Hi Randy! Been watching your channel since the Caballero and the Tempo. I’ve rebuilt GNs using the OTC2000 and can help you out. Shoot me an email if you want to talk more. 1. 13:50 Ignore the check engine codes and live data coming from the OTC2000. If you don’t have the right engine selection, it is untrustworthy. Once you hook up the Scanmaster, it will confirm what codes your car really has. Do it first before replacing the coolant temp sensor. 2. 15:05 - 16:00 Your car does not have a MAP sensor. GNs with the digital speedo have a Hobbs switch. Analog speedo cars have a MAP sensor. These two sensors have no effect on the running condition of the car. The purpose is to light up the factory boost lights on the lower right corner of the speedo (under “TURBO POWER”). 3. Inspect your driver side header for cracks. If your passenger side is cracked, the driver side is likely done for too. They usually split between cylinder 3 and cylinder 5. I recommend smoke testing the exhaust through the oxygen sensor. 4. These cars stay in open loop until the temp sensor reaches 155 degrees. Additional info: 2:46 Secure all vacuum lines, especially on the turbo’s cold side as well as that boost controller. We use zip ties on them so they don’t blow off. 5:26 highly recommend Pypes or RJC for their cat-back exhaust systems. 10:35 Does the other OTC 2000 do the same thing? After you press 2 for 3.8 V6, Buick PFI should come across the screen. That can be done regardless of if the scanner is plugged into the port; I just tested it on mine with the same cartridge. 11:32 Disregard the split second data, that happens even when it’s unplugged. Gotta love 80s technology! 12:40 Don’t be concerned if certain modes are blank, try another mode that has the same parameter. For example, Mode 1, 8, 10, 31, 40, 49 all have RPM as a selection but only one of them actually provides the real number. IAC could be present in Mode 42.

Randy, I'm almost willing to bet that you have a wrong ECM/PROM combination. Pull your ECM, and look for white tag on it. You're looking for Service Number 1227148 on the ECM itself. Then, there's a little door on the ECM secured by a screw, under it should be your PROM chip. A stock '87 PROM will have either CMW or ACXA printed on it. There was a recall chip for the '97's, and that one will be printed BBKJ. Also, one other thing - most GM's of that era used that 3 wire weatherpack connector for the MAP sensor. I saw lying under what you thought might be the MAP sensor on the right fenderwell. Take it all together, my money's on a funky little computer setup here.

Randy, get a scan master scan tool it is a must for all grand nationals. It will give you all the scan info you need. The MAP sensor controls nothing but the boost gauge on the dash. Replace temp sensor and 02 sensor and get a MAF translator and LS1 MAF. Love the channel!

I'm enjoying the direction Randy has taken his channel recently. Thanks for posting these cars for us

24K is a lot of cash no doubt, but if the vehicle was 100% and driving down the road the videos would be kinda boring! I’d rather watch you spin wrenches on this awesome car and bring it back! Watching those videos of the car you repaired drive makes the viewers feel part of that success 🎉

Shout out to all the sponsors, you're living the dream Randy...stay up, hard, and Free brother!

On top of that aftermarket mass airflow sensor, that huge orange end looks like its attached to the MAF with a wing and a prayer. Could be letting in a huge vacuum leak as well. Glad to see you're setting it straight under the hood. Good luck and thanks for the video Randy!

I think $24k for a partial runner is still a good deal today. A sorted out car is going in the mid 30's' to 40's. Mint GN's are in the 50's. I think you still got a good deal. I paid $19k back in 2014 and my car was a mint, stock 87 with 25k miles. prices are getting nutty.

Its never easy trying to fix a car thats been hacked on by previous owners. At least you have a direction to go now. Love that Grand National.

The grandnational I owned when I was 25, would not read codes when the fuse for the lighter blew. The obd port works off the same fuse. I got so tired of having to fix the engine problems. I put a 455 in it, and it bolted right up to the factory transmission. And that really made it fun and very fast.

Love this type of classic car Randy I enjoy watching your videos 🙏😇

That plug laying on the fender well looks like a map sensor plug

I'm looking forward to the fixes and see how the grand national really performs! Enjoy your vacation, we'll see you in a week 👍

That air filter looks like a vacuum cleaner filter

Fix the cracked manifold FIRST!

You're getting it done Randy, great job!! A second lift is needed for sure.

Once you get the grand national running good don't you think maybe you should try taking it to Mecum auto auction in Scottsdale ! I'm thinking it'd very well out there and give some added content to compensate the content you've lost ? It's just an idea! Obviously yould want to set a reserve that is comfortable with you ! I wish you the best luck whichever idea you go with ! Have a great day buddy

I would get a hold of Alex over at legit street cars. He owes you one. Remember when you had to buy that vet for him. He has one just like yours and not to mention the guy is pretty damn smart lol

Glad you where able to get some codes! She’s a beautiful classic car just has a few issues! Have you ever tried to talk to Alex from LSC? Think I’ve told you this before always look forward to your videos! Enjoy your vacation you deserve it!

That sensor is for digital dash boost gauge . I can send you picks on how it’s vacuum lines are run

i used to have so many diy diagnostic tools when i used to own and race gns and t-types. you really need to fix the basics. get and install a scanmaster. get a coil pack tester. get a maf translator, and an ls1 or lt1 maf and fix that jack show of an intake. check the plugs. check the tps voltage. idle air controls love to crap out on them. my god the list goes on and on with those cars. it was a real labor of love keeping them race ready.

Cannot wait to see the next video where you put all those new parts on her and it runs better and you get that passenger side header and that will help too.😊

O2 sensor probably won't read correctly with the cracked exhaust manifold...that is a common issue on the GNs...you need to fix that! Replace the coolant temp sensor, fix the exhaust manifold and I would probably replace that MAF with an LT1 MAF with a translator. Those MAFs were always very tempermental and easily damaged. I love the GNs, but they are by their very nature very tempermental...I've owned 3 of them. Enjoying the content.

Fix the damn cracked manifold...it's gonna cause alot of issues with a turbo car. I love the videos by the way.

Good Morning There My Good Little Bro Randy Lee Shear Auto Auction Rebuilds

She really runs good when she gets warmed up.👍

thanks you for the videos Randy cant wait to see you work on that buick and enjoy ur vacation be safe

the plug that is by that piece with the vacuum hose is were the map sensor should be the green plug is the plug for the sensor

Good morning sir. Good to see you again.😊👍

The switch on the passenger fender is for lock up torque converter snd the empty plug below that is for your map sensor

The connector that is sitting right there under what you believe is the map sensor is for the map sensor it looks like your missing the map sensor

The auto diogastic reader from 80s& 90s work's well for ur 80s muscle car collection Randy

Enjoy your holiday Randy!

Enjoy your vacation randy

Please be safe and careful.😊👍🙏 Enjoy your vacation.😊

The turbo wont work rite till the manifold is fixed.. enjoyed the sharing 👍

16:00 That 3 prong plug laying next to that diaphragm with the 2 prongs looks like an old GM MAP connector

Love the style of cars lately

Reminds me of my 87 Cutlass I had similar issues except mine kept going in and out of loop;previous owner removed the check engine light bulb! I had to get a heated O2 sensor and it helped alot and stayed in closed loop and ran great then. Thanks for your constant content; I watch daily.

Randy the empty plug by the vacuum sensor is the plug for the map sensor

Couldn't the crack in the manifold have a lot to do why she's running like total crap?

Randy that Coolant temp sensor helps the ECM with how much fuel and timing to use. When it’s cold its reading is way off, therefore it’s stalling. When it warms up it’s getting a reading(even though low and at 88-90 degrees) that the ECM can manage because it’s a reading the ECM can see with an operating temperature.

These solid state computers in the OBD GM cars were known to have problems with cracked solder joints. Also you can actually do a pinout test from the computer to actually check sensor values.

The crack is a huge exhaust leak = poor idle and stalling issues love the vids Randy🎉🎉🎉

Please fix the cracked manifold!! That would also help fix your problem instantly

OMG! That "filter" looks to be one of those Intex pool filters that I have for my pool....LMAO

The exhaust manifold and that connector that doesn't lead anywhere worry me on the passenger side

High or low mileage always something to rebuild/replace on these cars. Enjoy the ride!

Great idea getting another lift!

That Sunbird is too official 😍 that’s a hotboy car from the 90s 🥵

I’m really I joying these era if cars . seeing them brings back a ton of good memories, also I’ll trade you weather temps it’s 47 here in Ky lol. Hope you have a great day.

🗿💨the ox sensor is lieing to the computer.. imo. Manifold is prob the culprit. Imo. Enjoy you sharing this car👍👍

The map sensor is unplugged! The part on the passenger side that you thought was it isn't it but you can see the 3 prong plug for the map sensor below it. It's missing that's probably why it's running like shit.

Good start Randy 😎😎👍👍

Maybe?? this is from a Forum.... MAP stands for; manifold absolute pressure. It is a little rectangular shaped sensor, usually located on the passenger side firewall on a stock GN, under a small metal bracket within inches of the A/C evaporator housing. In most vehicles, it measures vacuum then sends a signal to the computer to calibrate fuel adjustments. In the Turbo Buick, it measures boost levels from the turbo, sends a signal to the computer for the same reason. The factory 2 BAR MAP sensor is only capable of reading boost levels up to about 14 PSI (This number may not be totally accurate but very close), a 3 BAR MAP is able to read boost levels much higher, which is needed when adding bigger turbos, more boost and alcohol injection. It's a little more complicated but, this is probably all you need.

That cracked exhaust manifold, could be making the O2 sensor reading lean?

Love it all Randy, all the best of luck with the Gran-National.😊👍

We can’t blame you! Man I love that car so much! Keep it up randy l!!

It should have a mass air flow sensor on the intake side usually found on the tube between the filter and the intake

Keep on it Randy! You’ll figure it out. There are some good commenters in here that mention the same things you did. Chase the Temp , MAP ,02 sensors and verify a good correct Computer and Prom and im sure you’ll see improvement. My Tech scanners read Temp in Celsius maybe your OTC does too.

Randy I own three of these cars along with several other rides as well. I know you have put new wires on the car but if you look at the video at 5:40 right before it dies you can see it sparking across the wires about a inch or two down from the coil. I seen it a minute or so before that. You may have a ground issue or possibly the coil or the module under the coil. Unfortunately you can't get any NOS parts. I know you will figure it out. Good luck.

You always build a shop next to your house where you live at your house so you can work on cars at home

You get that running it throws you into the back seat I remember I drove a brand new one back in The day you will see google c it's an awesome car

Main problems with the GN are fuel pump. There is a cam sync in the front you need to sure it’s adjusted correctly. pull pcm see if the is a aftermarket tune. Coil pack go out. Worst case detonated bent a rod.

Paper clip will pull codes on those obd1 cars .

Hey Randy love the card I use to have a 92 firebird formula red with the tan interior with the gold honeycomb wheels it was a 5 speed I miss it soooo much so if you plan on doing something with it please let me know love your videos and feel free to hit me up love to talk with you boss thanks again all the cars bring back fond memories

0:44 randy those wheels look awesome

It sounded like the idle changed very slightly when you messed with the plug on the puck in the fender

Temp sensor is likely reading out in Celsius on the scan tool. 88 deg is roughly 190 F

That coolant temp will cause all those run issues. GM has done this since it's been a thing . My 04 surburban did it when it's coolant temp sensor went out . In fact a lot of the time I got the reduced power code and blinking cel . Fix that the loose intake hose the not called for air filter and some fresh premium shell run like a top

Thanks for the Grand National Content Randy 🤘🏽🔥🖤

Have a wonderful vacation.

Temp may be reading C° instead of F°.

Randy, try the Buick regal T type with the turbo V6 on the scanner and see what that does

Great video,work and car😀

Can’t wait to install the replacement parts 😊

my test for window motors was to get in the car engine running, and slam the door while holding the switch down, it will probably work a few more times, just means the brushes are worn down in the motor, so the spring that pushes on them is almost extended all the way

Regardless of comments and wether the car runs or not, its a beautiful yard ornament 😎

See if that was my car I don't know who I'd bring it to. There may be a classic car tech closer than 5 hours away than North Miami.

15:13 the 3 wire plug is for a MAP sensor on an analog dash car to run the boost gauge. Your car is digital dash and doesn't use one. My '86 GN with 4700 miles (not a type o) that I bought new in 1986 has a digital dash and has that same plug just laying there. Hope that helps.

I’m with the guy below me! Fix the cracked manifold and go from there!

The map sensor is supposed to be plugged into that 3 wire connector on the passenger side. Looks like its not even there.

Check out the ball chiller vent under the steering wheel 😂

Randy you only paid 8,000 for AAHQ? in 2017? That's excellent 👌 I see the house and yard needed lots of work so yes hard work pays off

I think you should put in another lift in on the other side of the garage. You could get one more car in there

I think it has an aftermarket prom, they were really hot in the late 80s and early 90s and some worked very well, but the vin is stored in that prom, I would bet that is why the scanner is not reading the correct engine vin, no big deal just makes it a bit harder to diagnose problems but back then it was done with a multimeter and jumper wires and a good service manual, the codes were very basic and very little data from a scanner, and they were so slow so when you saw a change in data it happened long ago

Your map sensor is missing. It’s the 3 wire connector that has nothing plugged in.

Randy....Did you know your digital dash can be set to read metric also. Turn the reset knob clockwise to set to metric.I had a digital dash in a 1985 GN that I owned. Real rare in 1985.

Hello Randy. Trying to read the codes on the 1987 Buick Grand National to see why it doesn't run right. All of the stuff for the turbo charger is wrong. Replaced the spark plugs. $24,000 is a lot of money.

That Grand National is a must for me one day

The digital dash tells the story, you have no MAP sensor. I'm a complete novice, and just looked really quick for the info. Correct me if I'm wrong? 👍😎✌🗽

The cat is probably plugged. As soon as it gets hot thats why it is cutting off when it gets warm.

Have you checked the prom chip yet??????? The original chips do exactly what yours is doing ! Get a tt performance chip and a scan master!!!!!

Hey Randy, I just saw your video on the ground National. I hope you can get that car running correctly it sounds like it’s giving you problems when it’s cold outside when it’s cold let’s just say that but I know you and I know you’ll get it corrected. Can’t wait to see your next video on it. I’ll talk to you later buddy have a great vacation and I can’t wait to see you when you get back. Talk to you later.

map sensor on boosted cars have to be by a charge pipe

I borrowed that same scan tool from the ford dealer I worked at years ago and scanned an 88 olds cutlass supreme classic 307. It was a parts car we bought from a junkyard....somehow ran still (stuck on fast idle) but everything seemed in spec as far as the scanner was concerned. I just did it for fun.

Good luck randy

I think you need a larger shop, Randy.

I always love these 80s tech