S50 running issues

[Danny]

Replaced the cam position sensor, throttle position switch, coolant temp sensor, fuel pressure regulator and spark plug boots tonight.

Didn't help.

[328ijunkie]

^Stand corrected.

[Ryann]

I believe snapon might make something too but im pretty sure thats just for OBD2.

My MT2500 does OBD1. Adapter and cartridge are spendy though.

[gazellebeigem3]

Not sure what i did to piss you off but feel free to PM me to holler at me for whatever beef you have with me.

no beef homie, though you do come across as quite the smug cockjunkie

Humbly speaking i do this for a living and have ALOT of experience with these engines and troubleshooting issues with them. I am by no means 'the expert' and have not seen every situation or problem possible.

cool, me too. Though the important difference is that I don't come on the tech forums spracking off about how fprs never fail and how his injectors are too big and can't be compensated for by the antiquated obd1 dme.

And if you heard the video you can clearly hear a vac leak. :P

didn't watch the video on principle. these punk kids need to learn how to hold their cameras when they take video!

As far as OBD1 'Faults' Go: The only code youll get if youre lucky if its a vac leak or a Fuel pressure issue is a MAF code.

I guess that depends on what diag equipment you use. I can get a hell of a lot more that than from an autologic.

[328ijunkie]

Okay, update time.

Changed the fuel pump connector, much more solid now but no change in the way it runs.

Pretty sure I have a small vacuum leak from my brake booster, I ordered a new grommet today and it should be at work tomorrow. Pulled the vacuum line from the FPR and it runs the same with the line plugged or unplugged. I removed the fuel line and when it drained, the fuel would only drain from the side opposite the FPR, and none out of the FPR side. Thoughts?

Supposed to do that. Fuel only comes past the FPR when it exceeds the 3.5 bar pressure.

and INPA/DIS are about the only tools that can get a live datalog of OBD1. I believe snapon might make something too but im pretty sure thats just for OBD2. You also have to have a true ADS interface for it to work.

[F34R]

If I am right I want a picture of your gorgeous hair ;) lol good luck bro

[Danny]

I don't have the tools to pull a data log, it stumbles until 2500 RPM give or take 50 RPM.

[der affe]

Can you pull a data log from the stock ecu? I.would also check that out to see if i could track down the dxact rpms it was happening at.

[Danny]

MAF code at high RPM's + no change after MAF swap points to a vacuum leak. Attach a vacuum gauge the brake booster hose to confirm.

I'm going to borrow a vac gauge from a tech at work tomorrow. Will try to get a fuel pressure gauge as well.

[Ryann]

MAF code at high RPM's + no change after MAF swap points to a vacuum leak. Attach a vacuum gauge at the brake booster hose to confirm.

[Danny]

Okay, update time.

Changed the fuel pump connector, much more solid now but no change in the way it runs.

Pretty sure I have a small vacuum leak from my brake booster, I ordered a new grommet today and it should be at work tomorrow. Pulled the vacuum line from the FPR and it runs the same with the line plugged or unplugged. I removed the fuel line and when it drained, the fuel would only drain from the side opposite the FPR, and none out of the FPR side. Thoughts?

[Danny]

I did do the spray test with no obvious results.

Also, I appreciate all the help, sarcastic or not.

[e30user]

If there's a noticeable sound, wouldn't the ol' spray-stuff-with-carb-cleaner trick work? I'm actually curious about this. I'm still learning stuff, so this thread has been interesting. Have you done it since doing the most recent intake/vacuum related adjustments?

[328ijunkie]

My 2.8 ran fine with 21.5 lbs injectors and a OBDI with stock M50b25 tune. AFR's were perfect and it had no problems getting 30 MPG. Yeah I'm sure it would of made a little more power with a proper tune, it was probably still within 95% of possible power.

My OBDI electronics must be a freak of nature because OBDI sucks sooo bad.

As i told the OP (on the phone, using my shop time to help a fellow R3v'er). The injectors are not his current problem. The car will run and drive fine for the most part with bigger injectors. Just like all the M20 guys going to 19lb injectors on the "2.7i"s. I said specifically his problem from what i could tell is a vac leak. That doesnt mean the car will be running well running too much fuel like that.


And what did i do to piss the world off this week? Trying to help?.

[328ijunkie]

Agreed. I have also seen *gasp* fuel pressure regulators fail with my own eyes!!! 328icockjunkie appears to full of excellent advice today.

Danny if you're not setting any faults, I would run it with a fuel pressure gauge on it and go onto leakdown/compression from there if that didn't discover the problem. If that were caused by a vacuum leak, I think that the hiss at idle would be so noticeable that a supple young man such as yourself would hear it and quickly find a fucked connection or a cracked manifold.

Not sure what i did to piss you off but feel free to PM me to holler at me for whatever beef you have with me.

Humbly speaking i do this for a living and have ALOT of experience with these engines and troubleshooting issues with them. I am by no means 'the expert' and have not seen every situation or problem possible. Did i say it wasnt the FPR? No i said 'Ive never seen it' meaning its uncommon, not impossible. And by the way i was already correct once that he had the wrong main manifold connector to be fair.
And if you heard the video you can clearly hear a vac leak. :P


As far as OBD1 'Faults' Go: The only code youll get if youre lucky if its a vac leak or a Fuel pressure issue is a MAF code.