S50 running issues

[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]

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.

[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]

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

[F34R]

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

[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.

[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.

[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.

[328ijunkie]

^Stand corrected.

[Danny]

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

Didn't help.

[RoadHazard]

I may have missed it but did you check your O2 sensors?

[Danny]

I have an o2 sensor brand new in the box sitting in my garage. I didn't have time to jack up the car tonight but I will replace it tomorrow.

[Mr.SWISS]

Gawd damn Danny 4 fuckin pages and you still haven't done a smoke test or pressurized the intake to check for leaks....

I saw you replaced that notorious fitting on the IAC but did you test the IAC to verify operation?

This car has an A/F ratio issue either from excess fuel, or insufficient air.

[Danny]

Alright, pulls 52 psi of fuel. I did an injector leak down test and they aren't leaking. Put a vacuum gauge on and it pulls 15 in/hg at idle and changes with fluctuation of the throttle.

Runs better with no O2 sensor plugged in though, gonna go replace that now.

[Danny]

So here is a bit of fun info for you. I have a 15 amp fuse in my place of my 7.5 amp fuel pump fuse. The car runs like shit when the fuse is in place but if I pull the fuse it runs beautifully, until it dies of course. If I put the correct 7.5 amp fuse in, the fuse blows.