How To Test Fuel Pressures for Porsche 911 Bosch CIS K-Jetronic Fuel Injection

No video

How To Test Fuel Pressures for Porsche 911 Bosch CIS K-Jetronic Fuel Injection

Рет қаралды 6,682

Күн бұрын

Porsche 911 DIY Repair Blog: joe-engineer.com/
Step by step process on how to perform the fuel pressure tests on air-cooled Porsche 911s running Bosch CIS K-Jetronic Fuel Injection.
Additional Notes:
1. Applicable for Bosch CIS K-Jetronic cars 1973-1983.
2. Note: I am focusing on NA cars but 930 Turbo and early 965 Turbo cars running CIS also apply.
3. S&G Tools 33800 Test Gauge Set: www.tooldiscou...
4. Bentley Manual 1978-1983: amzn.to/3LgjrCG
5. Please take all necessary safety precautions. Not responsible for any personal injury or vehicle damage.
6. Shortcuts for convenience:
00:19: Intro & Fuel Pressures Description
06:15: Tools Needed
13:54 Test Preparation
17:12 Fuel Test Gauge Installation
19:18 Fuel Pump Relay Jumper Installation
21:27 System Pressure Test
24:40 Cold Control Pressure Test
26:44 Warm Control Pressure Test
27:03 Residual Pressure Test
If you would like to support the channel, please click this Amazon link and do whatever normal shopping you were going to do anyway: amzn.to/3yLlOGJ
IG: / joe_engineer

Пікірлер: 20

@marcing7684 Жыл бұрын

That's a great video. Thank You. Simply explained so anyone can do it. Too bad Bentley never did any service manual for 74-77 cars which also uses CIS

@marcelmed4574 Жыл бұрын

Hello Joe, very well explained thanks so much for doing these videos. I have a 1982 SC have learnt so much from you and did your smoke test from another one of your videos which allowed me to find a vacuum leak around the o ring of my pop off valve

@zachf6256 10 ай бұрын

Excellent tutorial. Thank you very much for your thoroughness and detail oriented manner. Approaching diagnostics in a man er that allows for expectations makes all the difference. Cheers!

@foxlair3682 9 ай бұрын

Extremely helpful as are your other videos. Has helped me a lot with my 83 SC. Thank you!

@miniprousa Жыл бұрын

from one Jose to another, thanks for making these videos. I'm dropping my engine soon and this will help me a lot. I have a 77 but this is great reference.

@turdrocket 4 ай бұрын

Correct on the arguments of this thing. That’s a rabbit hole. They all seem to work the same way, except placement of vacuum fuel enrichment. Between the earlier ones and the 81 to 83

@Jarratt. Жыл бұрын

Thank you for sharing 😊

@josesandoval9938 9 ай бұрын

Hi, when you did replaced fuel hoses from tunnel to press. accumulator to filter and rear engine ones, what did you use? Most NBR lines do not run well with ethanol after a year... I need to find original look, wraped look and pressed in not crimped...

@JoeEngineer 9 ай бұрын

E85 compatible polyamide in the tunnel and E85 compatible modern hose everywhere else.

@petermauro2268 28 күн бұрын

Hey Joe, Great video! I have a '82 SC that I rebuild (with help from my local mechanic). Your video helped to pinpoint what might be causing my cold start issue. However, my issue only seems to occur when my garage gets over 90℉, which is most of the summer (I live in Florida). Thus the WUR gets up to temp very quickly (10-15sec) and the cold start pressure (according to the graph) at 90℉ is about 3 bar, which does not give much engine warm up time. I usually have to step on the accelerator for a minute or two to keep it from running rough. Is there a solution for this?

@JoeEngineer 24 күн бұрын

Might need to send the WUR to get rebuilt/adjusted for your climate.

@christiangrann2810 Ай бұрын

Hi Joe Great video! I have a 1974 and had problems with my fuel system. This video was helpful in lack of the Bentley Manaual:-) I havent tryed it yet - but will certianly do. One question: I noticed your fuel pump did make som “noise” - or am I wrong? My pump sits just in front of left rear wheel and does not make that much noise when working in good order. The problem I had was fuel line on the suction side of my pump - it was deteoriated and some debris went into the pump inlet side which caused the problem I mentioned. The sound from my pump was getting louder and when reading Wayne Dempseys book “101 projects” I just thougth that the pump should be replaced. I did replace it - but at that point it was broken. They can not run without cooling of the fuel:-) My new pump (and new fuel line) works fine now - and my fuel filter is also replaced - it recived a lot of debri from the fuel line

@JoeEngineer Ай бұрын

The noise you hear in my video is my frequency valve, unique to US 81-83 cars. It is quite a bit louder than a normal pump noise.

@user-of2rj8rp8w 22 күн бұрын

Hey Joe, I did a pressure check and all we’re good except the cold control pressure was just a little under spec. Anyway, I have noticed a sort of galloping feel when under acceleration especially at lower rpm’s. What do you think could be the cause of this?

@JoeEngineer 19 күн бұрын

If your pressures are good I would proceed to reset the mixture and see how it feels.

@user-of2rj8rp8w 19 күн бұрын

⁠ok will do. I still have to do the vacuum test. Once it warms up a bit it runs much better, but it can still gallop a little. It’s at a pretty slow rate. Like just a slight tug at like 1 hz as I go.

@stevechiarchianis6439 10 ай бұрын

Hi Joe, I just purchased a fuel press. test kit, and will be testing my pressures using your video as a tutorial. I have a question about your jumper wire: what gauge wires did you use, and is that a fuse on the red wire? Is the fuse necessary? I have a ‘78 SC. Thanks…Steve

@JoeEngineer 10 ай бұрын

12 AWG is what the fuse holder came with. You should fuse it in case there are any other wiring surprises in that fuel pump circuit. Don't want to burn any factory wiring.

@marcelmed4574 Жыл бұрын

Joe, after all these adjustments. After warmup, if you pull up to a light does it smell rich? My 82 has had that issue for many years… it’s driving me nuts. I do have SSI. I beleive you have stock exhaust?

@JoeEngineer Жыл бұрын

Mine never smells rich. Maybe on cold start for a few seconds.