snflupigus

Ok, put WinALDL on Bruce's car tonight. O2 sensor readings all overthe board were pretty low (voltage). At idle the car was fine, under load, WOT etc... 02 readings are in the .1 - .01 range! idle shows .450 ish and decel is fine. Car is jerking hard and barely runs at all until it gets into closed loop. Injector spray looks a bit rough. Couldnt check fuel pressure today.

My guess = clogged fuel filter (realized it hasnt been changed for 2 years) DOH! -- come on, when was the last time you changed yours. LOL

OR, dreadfully, dying fuel pump?

Knock counts of course are of plenty!

Temp sensors is new and works fine, iac = fine.

Everything else looked ok to me.

Originally thought it was a dead ecm and wasnt going closed loop at all. Threw another ecm on it and it ran the same.

Throw out your suggestions everybody. Fix the moderators car!

snflupigus

code 44 thrown while still in open loop. blms go to 148-150 right away at idle once it gets into closed loop. ints are 148. 02 readings in open loop are .1-.2 ish.

Fast355

iTrader: (2)

Check fuel pressure under load. 11-13 PSI is the norm. Change fuel filter. Repeat pressure test. Still no go, check the regulator spring, it is common to see them break. Spring intact, change pump.

dimented24x7

iTrader: (2)

Probably the fuel pump. Ive had the filters go alot longer then that, unless the fuel was majorly contaminated.

ShiftyCapone

iTrader: (7)

Agreed. A dying fuel pump will just allow the car to run but horribly at best (7 psi or so). When my first pump went out I saw 5 psi and the car would barely idle. It was deceiving though because it would still provide a nice fuel cone out of the injectors.

90RS305

I do understand what problems a bad fuel pump cause, and it just doesn't seem to fit entirely with what my car does. The strangest part is when it is cold (well, coldER) outside, like in the morning for example, I can't even get the car to idle. I litterally have to fight with the thing. I can floor it and all it does is die. If I pump the gas long enough while scooting down the road at 20-30mph in 4th gear, I can get the engine to a high enough temperature (at least, thats what seems to be the determining factor) to where it will finally start to accelerate on its own power. If I start the car in the middle of the day, say around 3pm when its 110+ outside, the car will start fine and hold an idle. It still accelerates kinda funky, but not bad enough it prevents me from driving the car. Freeway speeds are no problem at that time as well. Then, when it starts to cool down at night and I haven't driven it in a while.....same problem as the morning.

I just have a REALLY hard time pointing the finger at that pump. Generally speaking (but prob wrong) when I've seen fuel pumps going out they make noises and tend to cut in/out, not slowly start to work then slowly stop working as the car cools back down. My pump makes the same sounds it has for the 4 years that I've had the car. Primes just fine when the car is put in the on position, and Snflupigus even commented on how quiet it performed when my car was holding an idle.

I already bought a new filter and will hopefully be putting it in tmo. That DOES seem like a likey cause for the problems, due to the fact that gas out here can be kinda shakey, and I have had to use a few, dare I say, generic gas stations over the last couple years on road trips.

And last but not least (and in an effort to not make a novel out of this post) is there a possibility my injectors could be effected by the teperature? Maybe they are gunked up and when the gunk is cooler it just doesn't spray enough, and when it warms up the gunk gets pliable enough that I can somewhat drive my car? Long-shot, but theoretically possible.....

Thanks for all your help guys...

Bruce (90RS305)

DM91RS

Bruce do you have a fuel pressure guage on it? And if so what does it read?

DM

Chadster86S10

I'm struggling with my new motor too..

Other than the fuel...
Don't have a plug wire off or burned?
Is your MAP/MAF ok?
Is your alt putting out good voltage?

It's probably something simple!

snflupigus

sensors all seem to be working correctly... I voted fuel filter or pump when I saw those 02 numbers.

Morning = cooler air, more air, no fuel. EXTREMELY LEAN... hot AZ air durring the day = less dense air, lean fuel = better mixture? Enough to run at least, but Bruce, even when your car was finally running in closed loop, your mix was way LEAN.

Get that filter replaced, if it doesnt solve the problem we can probably rent a gauge from autozone or something and check the fuel pressure. Pulling the pod apart to check for a broken spring is easy too.

IceManRS305

iTrader: (-1)

sounds ALOT like my car, im guessing its the pump myself.... anyone have a link to the fuel pump replacement thread? the one with pictures of cutting the trunk above the fuel tank to make the job easier and to gain full access to the pump for EASY replacement??

snflupigus

took 5 to replace the fuel filter tonight.... reset the ecm... car was still hot and went straight to closed loop but the WOT 02 readings were no longer .1 but now at .85ish. It ran A LOT smoother than what I witnessed the other night. The rest of the data looked good but a tune up with new plugs, wires, cap, rotor, and TIMING fix (its off) would make the car run stock again.

when are we doing it bruce... you're car is easier to fix/work on........... vs. the tune on mine. or the Alky injection on the truck, or the restoration and engine rebuild of the Porsche...

Let me know how it starts in the morning when its...er, cold? (only 100 degrees outside).

90RS305

Got out to it at about 9:45 this morning, and it did run a little choppy. Nowhere near as bad as it has been running, but still not perfect. I'm gonna have to try it again in the middle of the night for the best test run, so I'll post again after that. The drive home from your place was great though, I actaully could feel the car WANTING to go when I accelerated in 5th gear on the freeway. Something I haven't been able to do in some time now....

snflupigus

save up for that fuel pump... it will go soon i think... run some injector cleaner through it with a bit of 91 octane. 50 cents a gallon more is only 7 bucks a tank. You saved that by Michelle making dinner last night LOL AND your mpg will improve. you're knock is causing timing retard and bad fuel mileage. We might want to give you a bit more fuel pressure so the car is pulling it back vs trying to add it all the time.