88 2.8 GT about to be fixed! BUMPED!

[Vampcrist]

Alright guys so I'm working on this damned thing and can't for the life of me figure out whats going on. I'm having a problem similar to other people that I've read no joke I've gone threw all 32 pages on any 2.8 or 3.1 that sounds close to what I have and so far I can't find anything. When I'm driving it will just die. No real warning or anything most of the time idle's fine when it wants to start. Basicly I'll be driving along and poof no power. Sometimes I can hit the clutch and it will stay at high idle other times it will try to idle out and end up dieing. Up until today I could kick it a couple times in 4th or 3rd and it would come back on and drive down the road. Now basicly I'm down to three things. I've replaced the coils the module fuel pump relay fuel filter checked all wires (even the ones that are to close to hot things to burn the shhhh out of you) Nothing is loose nothing seems out of place. Now I've got about 160k on it but only about.... I belive I'm right around 7500 on the motor EVERYTHING is new except the alternator and my crank possision sensor. So I'm down to 3 things so far that I've read ECM, Crank sensor, or Fuel pump. Before I replaced the fuel relay I had code 54 for fuel pump voltage low or whatever it was but I've gone about 60 painful miles now and all I can get is 13. With the TPS disconnected the car does the same thing. If not driving throwing a rev at about 3500rpm it will cut and die sometimes it starts and runs and sometimes it wont so I don't think it's the TPS. I know this motor in and out and can't think much other then the fuel pump. Tests fine except I haven't gotten a voltage test on it but pressure when it wants to run is held steady at about 46psi running does the same unless it doesn't want to start. Anything would help and I hope my description will help as long as it is. I know the tank drop for the fuel pump is easy but it's the last thing I want to do. Whats the deal with the crank sensor can it cause intermedeat problems? Is there any way to home test your ECM? Last thing I want to do is take it to a dealershi[p and hacve them not figure it out. Thanks for any help guys

[Carson21R]

crank sensor. does it happen whens its hot or cold? because when they heat up they tend to not work and when it cools down it starts again. i had the same problem and it wound up being the CKPS

[Cliff8928]

I've had a few things cause a problem like that...

Most commonly it was bad (shorted) fuel injectors. This is usually a heat-related issue. It will run fine when it's cold, but will stall when it gets hot. You can measure the resistance across the terminals of the fuel injectors and they should measure around 12Ω.

I've also had my ECM go bad, but it would always idle, but when I would try and accelerate it would die out. That's not to say that it can't fail a different way. I could reach over and tap on it and it would be fine for a while.

If your crank sensor was bad, you would not see any RPMs when you were trying to start the car. (I think the analog tach normally still works while cranking?)

[Vampcrist]

Well It does it hot or cold I'm going to try to limp it home tomorrow so I atleast have it here to work on some I'll test the injectors and fuel pressure again as well once i get it here thanks for the quick responces

[Vampcrist]

Also I just thought about the tack mine is still analog when i crank it cranks right around 500rpm now most the time mine will also idle when it doesnt usually is when it wants to die out when im driving but if i can get it to start and keep it running it will idle all day long usually

[Vampcrist]

Alright so I got it home yesterday checked out the ECM a bit more its got the sticker on it from GM so its MAF by-passed for sure(also glad to know that for intake air) it doesnt have a date on it but it doesnt look like its all that old or anything. I replaced the crank shaft sensor and O2 sensor just to get rid of the annoying light and still no change. At most I can tell you that it will start cold but a rev to about 3500rpm and it goes to no power and then still starts right back up. If it gets warm its harder to start. I'm going to check the fuel pressure tomorrow I didn't have a gage here so I had to wait a day. Any other ideas if the fuel pressure tests okay?? Don't know where else to go if the fuel pressure tests alright. I'll have an ohm reader as well tomorrow to test resistance. Any good posts to check the power to them?? I've found a couple on here but not to discriptive and of course hanes thinks that no one has any idea what they are doing and dont give you much to tell you how to test it out. Let me know if anything else makes a light go on in your guys head thanks for the help and ill post more about the tests tomorrow

[DTMAce]

Does that thing have a TPS (throttle position sensor) by chance? I can't remember.

As for testing resistance, just pull the plug out of each injector as you check them, test the leads to see what the resistance is. There are probably 2 leads in the plug and I think you just test between them. Either that or each one is tested to ground. Your meter will not hurt it in any case, so don't worry if you get it wrong. But get some resistances, see what you have.

[Vampcrist]

Yeah it has a TPS but it's older non-adjustable style once i get fuel pressure tested here later in the day I'll post those results. Also started looking around a bit more information about the fuel pressure regulator on the fuel rail. What kind of malfunctions can it cause if it's going bad does it usually dump more fuel to where it could flood out the car or cause the pressure to be inconsistent? Also any way to test it if my injectors and fuel pressure come out right?


Edit:

Okay so later on today checked everything we could with what we had haven't gotten a pressure test but we did notice the alt after it had a spell of not wanting to start sparked like crazy and then quit after about 5 seconds after the car started and then idled out just fine any such problems occure that you guys know of would be nice because we didn't think that it would be a problem until we saw it spark. voltage tests fine but that was with the car starting to run and we didnt think about retesting it we where looking at fuel rail wires and whatnot. Let me know if anything comes to mind I'm going to go try to find one in the junk yard so i can test it out before buying a new one.

[Vampcrist]

Okay so the fuel pressure doesn't hold steady. I'm going to look around on here to see if i can't find a thread about it theres just way to many options I know the vacume is right about 17

[Vampcrist]

Alright injectors test fine the idle air control valve doesn't move very freely... they are bringing in the new one in about an hour and a half so we can see the difference between the two I figure it's one of the last things i have to replace everything now is getting up there in price range making it harder to replace damn you supply and demand!!!

[Money pit Beretta]

They don't move easy unless there is something wrong. If they were to move easy then it could be forced open by the air flowing in.
That I know of there was never an adjustable TPS on a Beretta. They can make a very high idle, but it shouldn't make a power problem.
Is your exhaust flowing well?
Did you try to unplug the EGR?
Just throwing some ideas out there.

[Vampcrist]

Yeah EGR is working fine exhaust needs work badly but the cat is probably less then 3 years old I'm going to look into getting the TPS tomorrow possibly and try to see if that doesn't do it past that I don't know what else to change out to make the damned thing run again. Voting the TPS fixes it tomorrow we will know!!

[Vampcrist]

Okay so NOt the TPS changed it out went out with it ran great again until you try to accellerate in any gear to where your almost WOT SO after a spell of it not wanting to start i played with the IAC pulled it out changed it's possision over and over FINALLY put it in gave it a few good wacks and boom car started just fine SO any idea's??????

[jeff540]

I would think the IAC controls idle only meaning Idle Air Control,shouldn't have any effect at WOT.

When did you change your fuel filter last? could be partially blocked,not allowing WOT,I have seen many problems since gas has ethonol in it now.I can't keep a fuel filter on my jeep for more then a month,the ethonol eats the china made fuel filters from the inside out.

[Vampcrist]

Yeah I've replaced about everything you can so far fuel filter CPS TPS o2 coil packs ignition module tested fuel pressure tested injectors both are fine vac at 17 wants to push to 25 at let off ive got one iffy vac line that still gets plinty of pressure so i dont know IAC can do a lot more to your car then you think as well as it controls idle it also opens and closes if not opening all the way at WOT you would have vacum still and be low on fuel pressure causing an injector fault and boom car is off but the way it acts when it doesnt want to start is like it has no spark or no fuel im horrible to tell but if you do the good ole trick with the plug wire off i have great spark and fuel pressure is fine and doesnt drop at all when cranking basicly don't know whats left to do at the moment any help would be great though and thanks for the reply