I agree with the other comments - if the problem went away when you were returning to the bottles, not the main pipework, maybe that is the problem. Try to replicate the issue - connect your bleed off lines back up, if she starts to misfire again, reconnect them to the bottles, if the misfire goes away again, well, it does really point directly to your bleed off lines being plugged somewhere. Being able to replicate the issue by doing the same thing is such a big help when trying to workout what is wrong.

Ok, i don't think your leak off levels are indicating anything particularly bad, however alarm bells rang when you said it was no longer misfiring with the kit attached. At this point I would be checking the fuel return line(s) all the way back for blockages or kinks etc as it could well be excessive back pressure in the return that is causing your problems.

The flow test dosent always show anything like you saw... on a scan tool in live data it's better to check the injector adaptive values. If one injector is adapting a lot more than the others then that's your faulty one

Try the return valve in the bango bolt in the pump .. had a few of them jam up before

Absaloutly brilliant video Ian miss hubnut ❤👍 it's always great to see when your sick my two favorite ppl on the internet I love you 2 guys brilliant

The best "car couple", on KZfaq 😊👍

another great video has always Ian and miss hubnut and hublets and hubmutts 👍

Mrs HubNut was the student but now has become the master…..

I love that James Walshe has now become something of a Berlingo whisperer. Seems like a top chap. Sadly my hypnotic jiggling relates to my dietary choices

interesting that Bella didn`t misfire at all once the test kit was installed, this would lead me to think that the return pipes could be the issue, so I`d put her back together & drive her home, then, if the issues return, I`d replace all the return pipes, then if that doesn`t solve it, move onto the injectors, as pipe is a lot cheaper & easier to change than 4 injectors (why just replace 2 when all 4 are the same age?). Also, you overlooked checking to see if there was still air in that filter pipe when the kit was fitted, if there wasn`t, then it`s a return pipe issue, so my 1st port of call would be to change the return pipes & take it from there. Do the simple/easy stuff first. :)

Been waiting for this for weeks! Come on...I've got faith

Interesting how the test with the little bottles seemed to stop the problem.. I’d go with looking into the leak off pipes etc before injectors, as they seemed to be doing there job ok when you rev’d the engine

On the Citroen, the fault with odd lights illuminated, will be a bad earth somewhere. 👍👍👌👌

Thought that was Boris Johnson…then I realised it couldn’t be…this guy is actually useful.

Interesting results in the test when it stopped misfiring. I do remember my first car (1982 Mazda 323) had misfire at one point in winter time, when it was getting warm. It never stalled the engine, just started misfiring, didn't even rev the engine for a while,, but after a while running at idle, that "misfiring seizure" went away, so could continue driving. It had the old school mechanical contact point ignition with capacitor / condenser, and indeed replacing the capacitor fixed the problem, after trying all the other ignition components first, adjusting timing etc. :D Next Mazda (1990 323) had electronic ignition, but when the ignition module fried, the car died immediatly on the road as the faulty module killed the spark with it.

Going back in what passes for my memory, I think we had a special tool like a slide hammer for removing injectors. Yes, they do get very tight! Sometimes a little bit of blow by occurs, so you get black goo that solidifies! A trick we used to try was to fill the fuel filter with diesel injector cleaner, then run the engine. Might work?? Hope you get Bella sorted. PS the fuel cleaner trick won't help get them out, just might clean them enough to improve the running

Wow..a proper A lister in the classic car world....Huge practical classics fan, subscriber to the magazine, best classic car mag on the market

Also, if you do decide to try removing injectors, try wheel cleaning acid down the holes for a few days before you try. Having said that, the leak off levels didn't seem to be different enough to me to try that madness, it's a world of pain and best avoided!

Bye bye Gisselle, You both know you want the 7........suits you😊 really good camera work, clear and pointing at the action.

Good luck at Tim’s… Everything is going to be fine again, I’m pretty sure. 🍀🤗🍀

To me that leak off test was fine, when injectors fail they leak a load of fuel and I've had a tube fill up in seconds, while the other ones have a few drips in it, i need to do a leak off test on my astra as is lumpy and goes in to limp mode

If it didn’t misfire with the tester attached, could it be a blocked fuel return line? (Total guess by the way).

Lexia is a good tool and gives you a lot of information if you know how to process it even in diesel injection and spill flows. Not had anything to do with the 2ltre model 1.4hdi 1.6hdi but even some fuel filters I have fitted I check all the drain plugs and fixings as they cause faults. Just think it's new out the box doesn't say its ready for fitting. I wonder if you have a damaged crushed return line back to the tank or a clog Only way is to find the main return and check and blow it through or pipe a return into a separate vessel. And go for a road test

GSA lights puzzle - you have probably done this already but follow through the wiring looms for affected lights and check no signs of melting/burning where wires have rubbed against each other.

AY UP MR AND MRS HUBNUT

Enjoyable caper , enjoyed watching it in Cheshire thunderstorms

I put off removing the injectors from my Mk2 scirocco for YEARS, and just decided to live with some hot starting issues - bigger battery so it could crank for ages! 1.8 8v kjet engine, which are notoriously difficult injectors to get out, various homemade tools for the job and tales of woe on the forums. Eventually for other reasons I decided to go down the engine swap route, had to remove the injection system before hauling the engine out. To my amazement/horror they came out with such a tiny amount of leverage (maybe shrunk seals were the cause of my issues...) but I'd hyped it up so much in my head before even trying it. IMO, maybe there's no harm giving them a half hearted go? When it gets to the point where you're applying "I could damage this" force, time to stop and rethink. Though from the comments it looks like you might not have to take them out after all! Good luck, and hopefully the Berlingo is back up and running smoothly soon.

Interesting comments below. Also noticed that there seemed to be a bit of air bubbling through #1. It might have been the vibration causing the bubbling, so I'd suggest checking the footage and poss re-running the test, but bubbles might indicate air being drawn into the fuel system. Unsure about the Belingo's system but quite a lot of diesels draw fuel from the tank through the filter using the fuel pump, (esp indirect injection) at a rate determined by engine speed with the fuel use determined by engine load and pedal position. The excess is returned to the tank at ~atmospheric pressure. All in all, air in the fuel draw side causes probs and misfires. Blockages in the return, I think, are less likely to cause these. All the fuel ‘pull’ system is quite sensitive to filter restrictions (whether tank pick up or nearer the pump) and tank breather, too. Don’t forget this! Bleed off and return might be related but I’d want to check for and eliminate air pull-problems first. If you think you have return blockages, blow through the pipes with your air-line and look for kinks, too. Finally, I wonder if the scan software might have been able to log live data for the injectors, not just scan for codes. Plenty of cars etc from this era had the ability to log fuel pressure at the injector, fuel metering by the injector and a variety of other things such as expected and observed pressures and the like. It can be hugely useful to see the live logging data at idle and while under load, esp at constant speed in gear to look for anomalies etc. Good luck!!

That leak off test looks pretty good to me. My guess would be more of an electronic triggering fault in an injector when driving her.

Am inclined to agree with you say injector 3&4 are poorly. Hope you can get it fixed soon

I have just got an eml light on under hard acceleration ( goes off again in 10 seconds) on my 93 Cavalier MK3 . Not laptop or special software needed just a paper clip required to read codes. No3 injector low voltage so it's a £25 replacement and be done in an hour then.

A well worth test - based on my experience of doing a leak off test all 4 injectors are behaving the same in terms of leak off - No 4 did leak a tiny bit more over the duration of the test but no 2 injectors that have covered a decent mileage will/should leak exactly the same - to put this in perspective my car leaked off at a massive rate - 15 seconds and most were over filling - the engine ran perfectly, just smoked a lot on a cold engine - on my car the injectors were a more modern design that exhibit different symptoms than on the Berlingo. Bear in mind that if the leak off rate is small as is the case on your test the high pressure fuel pump will more than be able to sustain adequate pressure on the fuel rail - as others have posted if disconnecting the leak off return pipes during the test cured the problem then look there - if the engine starts and idles fine on hot/cold then the injectors themselves are likely to be fine - at this stage of investigation - If the engine does not produce smoke on idle or under load etc. then I would suspect the afore mentioned or the high pressure fuel pump is not delivering the required volume of fuel to the injectors at certain engine speed / LOAD. There may be a governor system in the pump - I don't have knowledge of high pressure fuel pumps but I would be looking at getting it assessed - Lets get a move on as its camping season - get the pump off and get it looked at

Finding a good replacement head, would be an option for the Peugeot, and possibly cheaper than paying to have the injectors replaced, and changing the head you could probably do yourself.. 👍👌

It may be worth checking the entire return flow system, including the tank breather solenoid valve. good luck.

Woo whooo car fixing time like content like this

I agree with the comments below about return pipe, but also, with fuel system problems, it's always worth adding a bottle of (in this case) diesel fuel system cleaner (Redex do one).

Before looking at injectors I would check there are no air leaks in the supply fuel line, often the primer bulb can leak air into the system particularly at the joints. Also fuel returning to the tank too easily via the in tank sender unit can be an issue, I think there is a rubber valve at the end of the return line that should only let fuel back into the tank under enough pressure.

I’m not massively convinced you have a particularly bad injector. Usually they are either good or bad and bad ones do tend to be bad bad. If you do pull the injectors replacing the seals is a given. If you do this regularly then you should get no blow by issues and this no stuck injectors. It would be interesting to monitor the live data for the injector pulses side by side as I have known intermittent wire breaks on these looms cause issues. This would clearly show if you got a scope on it. Picoscope is a good tool for this.

As mentioned by the other chap, if the problem seemed to go away on the first leak-off test but then came back, it could well be wiring. Try a 'wiggle test' - ask Miss H. to hold it at an rpm which recreates the fault, then wiggle wiring looms and connectors to see if it comes and goes. Could be a simple fix.

Everyone loves Betty 😎👍 Agreed

Leaky injector on 4 for sure. You could try cleaning in situ but the best solution is to replace. The engine sounds OK still but excess fuel will ruin it eventually. Removal is a swine but replacing is straightforward. Doing it in summer could be your biggest mistake (stand in the shade !) lol. Good luck.

It could mean 1 2 3 are bleeding off more of the air in the system than no4 even though 4 is actually 1 because french. For the purposes of this discussion though 4 in closest to the gearbox. I would try to have a proper fuel pressure test done before doing anything else. The diesel pump should be pretty easy on this cara since it doesntrequire any timing supposedly. They might be an injector problem to but I am pretty sure seals in the pump are perished and it dras in more air the more you work the engine hence it misfires when you are actually loading it by moving it rather than just reving on idle. Confirm everything before the injectors is working and air tight before touching the injectors. Injectors will set codes the pump will probably not.

I would say check fuel return pipe for blockage, some crap could have been picked up in it, blow it out with a low pressure airline but make sure the fuel cap is removed first.😊

Hook up a litre of liqui Moly to purge your injectors,the stuff works miracles on dirty injector's

A worn throttle potentiometer can cause mis-fire flat spot issue, however I am not sure that Berlingo's are fly by wire. Spill return IS an exact science, Ian, you time the run each tube has calibration marks. Put lots of WD40 around injectors, run engine to hot, put more WD40 on injectors, run again. Then remove injectors. you could scope the Injectors, make sure they are getting PWM equally.

A good man knows his limitations, as Clint Eastwood once said. Mr Walsh is therefore a good man.

Having just done 4 injectors on my 1.4 HDI (Ford fiesta flavoured) i can confirm they are a pain, but not impossible, got 3 by soaking in penetrative and rotating but unfortunately the slide hammer ripped the body off leaving the nozzle in the hole on the last one, Some very time consuming dentistry with a dremel eventually saved the day. Good luck if this is the path you choose

If its a "common rail" diesel the engine may go into limp mode if the pressure in the rail drops below a certain amount. Pressure loss is caused by leaky injectors. There is normally one injector that can fill a coke bottle in a very short time but your injectors are roughly the same. It suggests they are either all reasonable or all knackered. I dont think replacing number 3 and 4 injectors will solve the problem. By the way, on most common rail engines there is a sensor which records the pressure and this can be read via the OBD. If the pressure is below minimum this would suggest all the injectors are worn but if the pressure is within limits (and given the results of your leak off test) this would suggest that all of your injectors are OK. Hope this helps and best of luck

As stated by many already, check your return lines... the issue wasn't present when they were disconnected...

The return test should be performed at idle and you should find about 22ml in 3minutes. With the diagnosis tool you can also check the parameters for the injectors correction but also fuel and air pressure, air flow, you should be able to find something wrong. A compression test could help also as some of the 2.0HDi could drop the valves seats

A couple of weeks ago the check engine light came on in my 2014 GLK250 Bluetec and it seemed a little low on power. A couple of days later it started emitting a howling sound, but only under acceleration. The culprit turned out to be a split in one of the pipes that carry air from the intercooler to the engine. Thing is, once the pipe was replaced, the engine started throwing codes for the MAFS. With a new MAFS installed, it started throwing more strange codes. My mechanic reinstalled the original MAFS which didn't eliminate any of the new codes. At this point we both (mechanic and I) agreed that the car needed to go to the dealer. Appointment made, I went to pick up my car. As I was still in the mechanic's yard with the engine running, the check engine turned off and hasn't turned back on. The car is now running perfectly. I still kept the dealer appointment because there's also a recall that needs to be performed. Anyway, this story of woes is just a reminder that cars can sometimes surprise us with unexpected issues with unexpected causes. Good luck to you, I'm pretty sure that whatever it turns out to be, you will be surprised.

We had fun and games with my dads Nissan 1500cc diesel, to start with he bought the wrong injectors, then bought the right ones one by one, we have diagnostics but it was more trail and error the issue it had was trouble starting that got worse, He bought 4 correct injectors we fitted them one by one and coded them in one just wouldn’t code in how ever many times we tried, but the car starts spot on a runs great even though one was never coded to the car 🤷‍♂️

I think the clue is in it running fine with the kit fitted. I think there's a split or clogged leakoff pipe that's drawing air back into the system and messing up the pressures, making it almost burp itself (and show as a misfire).

Change the fuel filter. Fill the new one with injector cleaner. Put around ten (yes ten) bottles in the tank with only around 1/4 a tank of fuel. And drive around to clean them up. Then always use shell optimax. It makes a world of difference to these dci engines!

Ian - a thought about your wiring woes on the GSA.. Many years ago I replaced an engine on a Metro, after the transplant we had all sorts or wiring oddities (wiper stork activated the side lights, main beam worked the hazards etc) turned out we hadn't bolted the starter relay back in correctly (bad earth) just wondered if you had removed anything to give you access for the alternator?

New injectors, then chip her…different beast…transformed 😃👍

I had a slight misfire on my honda civic diesel. it was just a cheap run a round car so i didnt wanna spend money on it, cut a long story short. i bought a bottle of wynns injector cleaner. put it straight in the tank,,, and that cured the problem and it only cost a Tenner

Great HubNut video, where nothing much happens and some minor incompetence is revealed. Only thing is to get all 4 out and find someone with an injector tester.

Your fuel return pipes are blocked I reckon . I think you proved this by connecting the kit , seen this issue before

Apart from the leak off return being blocked or restricted somewhere, you really should try and find where the air is getting into the fuel feed, that air causes fueling problems, misfires and bad running. The problem is the air could be entering from anywhere from the tank pick up to the fuel filter. Car on a ramp and a careful look for damp patches on the fuel lines can help spot problems.

Hope it's sorted soon, if it is an injector fault I hope it's better priced than Skoda/VW's prices.

I'm no diesel expert, but the variation between cylinders doesn't seem that extreme, given that Bella's an old engine anyway and won't be perfect. The fact that the misfire disappeared with the leak-off test-kit in place suggests that the problem lies in the return circuit and not with the injectors themselves. I'd certainly look at the leak-off system before spending time and money wrestling the injectors out.

Happy tinkering @HubNut

Maybe 2 of those injectors are just dirty. You could try to add injector cleaner to the fuel. Or maybe ATF.(Which has lots of detergents in it and will mix quite well with diesel fuel.) Then run it until you need to fuel up again and monitor if the engine starts behaving any better. DO leave all connectors properly connected!😂😉

Wasn’t that fella one of the iterations of Dr Who?! 😂

my guess is that the injector is gummed up inside and the other one is getting the same as the other. can they be refurbished or rebuilt? - may be cheaper than getting new injectors. If so have the 4 done at the same time

Cannot help you with the issue but hope you can get Bella sorted and back doing the daily duties.

Ian before u start messing with the injectors run some cataclean through it ,but for diesels ,u can get it 😎should sort it ,try it

All you need is an injector socket set plus as well as injector replace copper washers with new.

Have you considered ultrasonic cleaning. I have heard on a motoring programme about the technique. Maybe help. Hope Bella gets sorted Ian.

Hello I've got the same engine in a xsara vtr and I've removed the injectors and on a xantia with the same engine and I honestly wouldn't be worried about removing injectors they do come out really easily on the 2.0 hdi 8v,

ian i think i would be getting the fuel lines checked over ,all so correct route as the rear axel has been off

Hi, seen this issue many times including on my own vehicle. Its simply either 3 things, the glow plugs or the egr or fuel rail sensor, first what I would do is buy some dpf cleaner the 5 litre one then put it in a pressure spray nozzle and squirt 2 litres of it through the air intake whilst somebody is revving the berlingo at 2000 rmp which will clean the egr which would 99 percent fix the issue as the egr is getting stuck from the carbon deposits. if this doesn't work then put a new fuel rail sensor on it and if that doesn't work then try the glow plugs.

if the car runs ok with the leak off tester installed then you need to look at the fuel return, the solenoid on common rail injectors actually controls the fuel leaving through the leak off port, changes the differential pressure etc, so anything blocking that fuel will change the way the injector work, perhaps the timing. the fact that it runs well with the tool fitted means you need investigate. I would start by either feeding the return pipe straight back into the tank through the filler or into a can under the bonnet. take it for a drive and see if the issue has gone. if that works then you need to blow out the return line or / and examine it very well, perhaps change it.

When salvage rebuilds did that test on the fiat engined van their jar were twice the size and filled quicker, so based on that yours look ok, the french build a decent motor but electrically they suck.

Modern common rail diesels are pretty complex, and if the service items are OK, then the only sensible option is to find a diesel specialist and have a proper diagnosis carried out.

Time for a tuneup with the old sonic screwdriver 👍

My diesel Mondeo had injector problems. Diagnostics said number 3 was the problem so i had it sorted and about 3 months later it happened again. Apparently they work in pairs so i had to have 3 and 1 done and then it was fine but i was a lot of money out of pocket! Not sure if this is true for the Berlingo too.

this is probably unlikely but... Something that might be worth checking out... Capacitors inside the ECU. I know a lot of Ford's and stuff have issues with electrolytic capacitors going open circuit and leaking physically inside the ECU, and that apparently causes misfires, not going into open loop, etc etc. Although that mostly applies to their old gasoline engines, so I doubt it would be this issue but just a thought that struck me while watching...I have no idea how these Berlingo ECU's are constructed but they are coming up in age aswell, so it could be something like that, just a thought! It is very interesting that the misfire stopped for a moment when you were using the measurement kit - perhaps it is a return line issue? Best Wishes from Sweden!

I checked the injectors on the MX5 by using a large long screwdriver as a stethoscope. I soon found an injector that wasn’t clicking. That was the one that was knackered. Quite easy to replace but no so on a diesel I imagine…

Citroen injectors need a special spanner to remove them, I did on my multispace, its interesting that the missfire doesnt occur when that kit was attached which would point to the return lines being the issue my 1.9 diesel injector no3 had a wire on it and reported injector faults to the lexia, im rather suprized that the lexia didnt detect an injector fault, have you checked all the return lines for splits in the ends of the pipes for cracks or splits, it could be pulling air into the fuel system that way, the little return lines next to the injectors often get neglected over the years and its a dirt cheap fix if it is that. The XUD engine fuel filter housings can leak air with age to, often the bitron seals on the top of the fuel filter housing lid and underneath the filter housing (if you pull the fuel filter there is a bolt in the bottom of the fuel filter housing) they can perish allowing air into the filter housing. when was the last time you unscrewd the filter water drain on the bottom and drained it? maybe youve picked up some water from a low tank in a garage, or maybe youve been to a Morrisons garage they are terrible for supplying us water in diesel fuel. I avoid Morisons garages like the plague since my mechanic showed me a mix of diesel and water drained from a customers fuel tank on a Citroen over 2 gallons of water. it would be interesting if you could attach some clear fuel line on the engine side of the pump or exiting the filter housing and see if you have air bubbles in the line whilst the engine is running, this would cause the car to stutter as the spray pattern on the injectors would keep being interupted and it would only get worse with time as you seem to have described. I am inclined to believe that what you have is air in the system, I dont know if the berlingos have a diesel fuel heater on the back of the engine, BX's definately had them, many were discarded as modern fuels were introduced with lower freezing temperatures of the fuel, the diesel heater has a tendancy to corrode at the pipe joints on the back of the engine and let air into the fuel system, often when garages fit a new fuel line on an aging Citroen diesel they now bypass the fuel heater curing the leak of air into the system. Id definately try a piece of clear fuel line connected to the exit line of the filter housing first to see if you have any air bubbles in the fuel, at least you can then rule it out and move on.

Have you tried replacing the boost control valve I know when they go wrong on the Renault f9q they give all those issues.failing that some decent quality diesel some injector cleaner and a thrash

Did the misfire return after refitting the leak off pipes? Did you check live parameters with Lexia? Particularly check that the fuel pressure is stable when the misfire is present. The symptoms may also be consistent with a restricted exhaust system.

I've only ever looked into injector replacement on pugeot boxers/ citroen relays and it's relatively straightforward there, they aren't especially fragile. I wonder why they're so much of a pain on these

Can't remember the mileage on Bella but injectors do need to be changed at certain mileages along with injector pump overhaul and a thorough fuel line check, change always as a set, check manufactures workshop manual for when (online?). Often before 100,000 on a car, even on a truck or bus, but should never be over that. Over 5,000 gallons of fuel would have passed through each injector.

Never had a problem with that age Peug/Citr engine taking injectors out unlike newer vehicles where you hang the car off of the engine crane vier the injector or smash the cylinder head off around it like a Renault traffic, BUT you did not get the symptoms while doing the test...what did you do to set up the test that stopped the symptoms ? that's the diag route you need to go, repeat and prove. You also may need a refacing tool to clean the seats if you do remove the injectors. xx

There's a new type of diesel injection removal tool that relies on a rapidly vibrating pneumatic slide hammer that vibrates the injector free and it's designed for really stubborn jobs where traditional 'brute force' extractors can cause damage. Might be worth Googling to see if these can be hired. In an ideal world, there would be very little diesel in any of the bottles but since your engine has done some miles, there is leak off but at least it's fairly equal across all four bottles (all four injectors have worn more or less equally), albeit a tad higher in injector number four. If just one of the tiny orifices in the injector nozzle has blocked , then the spray pattern is affected and thus combustion, and internal fuel pressure in the injector will climb thus causing higher leak off volume back through the return/leak-off system. Excess leak-off if allowed to continue can cause the high pressure fuel pump to work harder than it needs to because it's detecting a more rapid drop in fuel rail pressure. This can also have the side effect of making the low pressure tank lift pump to also work harder than it needs to in order to try and get the required volume of fuel to the high pressure system. This is where oscilloscope/Picoscope diagnostics can be useful to see voltage/current draw on electric lift pumps. The next stage would be removal of all four injectors so a spray pattern test can be carried out on a diesel injector test bed. Worth noting common rail injectors of this era aren't particularly complex to take apart. Loads of videos on YT where the mechanical bits of the injectors and nozzles are cleaned in an ultra sound bath.

Could just adding a strong injector cleaner to the fuel be a possible solution? Can't hurt to try. Good luck with a great car.

Furious driving or tasty classics are your best bet.

I'm not an expert but your diesel fuel tank must be full of crap. Well you can always sing. "MAE HEN WLAD FY NHADAU" Plant a tree or a shrub. I planted a Victoria Plum tree and a gooseberry bush. Best thing you can do ever !!!!!! Fantastic video.

Many says orfull things about the Berlingo! And they're right! Would loose my manhood owning One! 🤢😜🔝❤️

I think Miss Hubnut had been about to say "you wanted a Honda"...could an FR-V be coming soon? It'd be an interesting comparison for a family car test...

Sounds like what my old Peugeot 306 HDi did as the lift pump in the tank started failing, I had what felt like a slight miss at partial load at around 1800 RPM from memory. Checked the fuel filter for swarf ?

where did you buy injector test kit

The injectors are probably original so have done well to last that long

Is the return pipe blocked perhaps?

I've never had problems removing injectors on 2.0HDis. I've removed eight in total.

Check the return line mate

I think it might be worth you spending £££ and getting the injectors replaced. My 207sw was doing the same and new injectors has not only cured all similar problems but boosted the motorway Mpg from 59 to 72. That's 72mpg from Perth to Leeds and then down to Deal and back again... Change the injectors!!

Have you tried aiming a laser temperature guage at the exhaust manifold branches , see which cylinder is running cooler ?