help thinking possibly my ecu

[fncrazy]

OK I have a 97 talon fwd. My at time runs great the out of No where runs like crap. Some times it will not go pass 4000 rpms. Others it pulls very hard and boost to like ten psi. When it runs like crap I hear the the Turbo spooling up but just goes to five psi. I just got it and yes it had a bov to the atmosphere boooo. The does leak ever so slightly thar's the only leak I saw. The car is stock. Also have code p1105. I was reving in my drive way and one out of five times it didn't go pass 4k rpms. Also as I did that my battery light was dim the in higher rpms when away then it came on bright in the high rpms. And has not been on since.it does run lean at idle like -3.2 and rich on boost. I know I'm all over the place but this car has a whole lot of problems to start. One last thing yes the wires r crap going to change and the plugs r autolight 63. Just trying to rule in or out the ecu. Or should I start with the obvious. Thanks in advance

 

[bigtimmyd]

I would get new plug wires, re-vent my bov back to the turbo and do a boost leak test/fix leak. Then you will be able to narrow it down more. In my 1g, when I tried to vent to atmoshere, it would barley run (really rich), I eventually will when I get my gm maf and maft.

 

[fncrazy]

OK so I regapped the plugs one and four where way too open and it drove a little better but still having the fuel cut out feeling randomly. Getting a fmic Friday with new piping. I'm trying to see if I should get an ecu also. I have seen on here atlease one problem like mine that the ecu fixed. Anyone else have this problem?

 

[bryanwheat]

The battery light coming on would indicate that the alternator is on it's way out. The code is for the fuel pressure solenoid. If the solenoid is still hooked up and not functioning than it would be causing the car to run lean under boost.

 

[delta448]

When it runs like crap I hear the the Turbo spooling up but just goes to five psi.

Boost leak test. Actually do one, don't just look at it and call it good.

Also have code p1105.

OBDII Diagnostic Trouble Codes
As stated, that's for the FPS:

The code is for the fuel pressure solenoid. If the solenoid is still hooked up and not functioning than it would be causing the car to run lean under boost.

AFAIK, the FPS is only used for warm-restarting. It cuts off the vacuum signal from the intake manifold to the fuel pressure regulator when the ECT is above a certain value, which raises fuel pressure back to base. This is needed to re-establish the port wall fuel film that has completely evaporated due to a hot engine.
I think I understand what you mean though Bryan, if the FPS is blocked, it can cause the FPR to not see any reference pressure from the manifold, ie -rich in vacuum and lean in boost.

it does run lean at idle like -3.2 and rich on boost.

What do you mean by -3.2?

Just trying to rule in or out the ecu. Or should I start with the obvious. Thanks in advance

You had to ask this? If you have something simple that you know is wrong and you replace a perfectly good ECU, you still have that same something simple that's wrong.

OK so I regapped the plugs one and four where way too open and it drove a little better but still having the fuel cut out feeling randomly. Getting a fmic Friday with new piping. I'm trying to see if I should get an ecu also. I have seen on here atlease one problem like mine that the ecu fixed. Anyone else have this problem?

Hold off on the FMIC until you find and completely fix this problem.

If it were me, I'd try connecting a vacuum line directly from the intake manifold to the FPR, completely bypassing the FPS at least until I could get a replacement. It might take a couple of extra cranks to start it if the engine has not had time to cool back down, but at least you know your fuel pressure won't cost you an engine.

 

[fncrazy]

OK ty will do. And What I meant by -3.2 is short term fuel trim and I also did do a blt it was fine at 18psi. I also did bypass the fps but it seemed like it wanted stall coming off the gas. I do think the alt. Is On it's way out but now it's charging 13.9 loaded. thanks for the help any advice is greatly appreciated. Also my grams per second are at like 6.2 not sure if that's right at idle? I will do one more blt to see if there is a leak.