TransAmman87

This problem is becoming a growing problem without any solutions. My 90 T/A is having major engine issues... rather a small problem leading to much bigger problems, it is dumping fuel and running real rich. The shop I took the car too was unable to diagnose the problem. Here is a break down of the 'symptoms':

The car has lumpy idle with the tach jumping slightly, car completely shaking more than normal, lacks power under acceleration as in it just doesn't want to accelerate and boggs down to the point of stalling. The mechanics are dumbfounded as to what is causing this. The only code being thrown is the one for rich fuel. Everything else is apparently working correctly from what they tell me.

Anyone have similar issues or any experiences. This is driving me insane because this car is my daily driver and I have so many places to drive too right now

patgta

is your bird running rich or just experiencing bad fuel mileage; there is a difference between the two. Does the car still feel lumpy once warmed up to about 160-170F and higher? When is the last time you had a tune-up (replacing cap, rotor & etc).

pat

TransAmman87

At the beginning of the problem, the drivability issues started once the car warmed up. Now, it is through the whole temperature range. The car will not exceed past 40 mph and is basically choking itself out. It is running rich, granted the fuel mileage is now not so hot due to this fact. Before this, I had no problems with fuel mileage, its all of a sudden that this lack of power and eratic idle have started. Could my CAT be clogged? Fuel pressure regulator having problems the mechanics didn't pickup? I have been running through my mind as to what could be wrong with the car. Its kind of disheartening when the diagnostics tools couldn't pick up the problem except that the car is running rich.

SpitotRs305

well you could have clogged your Cat by now... but i think your coolant temp sensor might have failed causeing your computer to dump fuel into the motor... i dont think your FPR would cause this as it probably would have been more eratic in the begining than only after the car was warm.

DBLTKE

iTrader: (1)

A simple way to check if your cat is clogged is to measure the vacuum. hook up a vacuum tester and see what it initially reads. Normal is about 18-22 HG. If the vacuum starts to drop as your engine gets warm then you have a clogged cat. Also once its warm rev your engine to about 2000-2500 RPM for about 20 seconds to a minute. If you see vacuum loss while it is revved up it also means you have a bad cat.

Symptoms of a bad cat include loss of performance and your engine running worse once you get to operating temp.

You could also remove the cat and see if your car runs any better without it.

TransAmman87

I talked with another mechanic today about looking at my car. Over the phone he suggested the culprit being the FPR even though the other mechanics told me it was ok. The reason he believes it is this is because he has had experiences where the FPR tests show that it is working correctly but it has little surges causing more fuel to flow through it. He told me to bring my car by to have a look over... and he also said that the CAT more than likely is getting clogged now at this point which I kinda already figured now. I will double check the Temp sensor though, its not going to hurt double checking everything. Thanks everyone... anyone else have any similiar troubles like this?

bilms01

In my experience the FPR problem I have seen most is the diaphram get a small rupture in it which will not allow it to regulate, basically full pump pressure. If the diaphram ruptures it can also suck fuel from the regulator and directly into the vacuum system causing a uncontrollable rich condition.

Since the problem originally got worse as it comes up to temp I would suspect the coolant temp sensor. It can fail at a point in between open and shorted IIRC the ecm looks for a voltage between 5V ref and 0, it might not set a code if it sees any different value.

With the coolant to normal temp scan the coolant temp the ECM is actually seeing, it may only see the engine temp at the cold side and is trying to compensate by dumping fuel.

The CAT is a definate concern as a symptom and not the root cause. Most of the cases I have seen the CAT is a 'victim' of other problems.

patgta

i once had a clogged cat, and the mileage was really bad about 11mpg (city and highway) and performance fell down a lot aswell. It got to a point where i couldn't reach a speed of greater than 70km/hr (about 50miles/hr).

The reason my cat failed on me, was just wear and tear over time. My car is a 88 tpi and the cat went bad in 2000, so i got 12 years out of it. The life expectancy is about 5 - 10 years and about 3 years for a high flow cat. Of course there must be a reason for this cause, so like the other guys have mentioned testing the FPR is a good idea. But I personally would also check or replace the 02 sensor since this is the most common cause of a slowly clogging cat.

Pat

TransAmman87

I took my car to Pep boys the other day, the third shop that I have had my car, and I just wanted them to change the spark plugs for me as a way to see if that may be one of the causes of my engine woes. My check engine light came on again while driving there and I decided to have them do a flow test just to double check some things. Anyway, they found that the 4th and 8th injectors were not working at all. This would explain many of the problems. I am going to work on my car this weekend and hope that everything starts working correctly again. Its almost spring time, its time for my car to run right! Thanks everyone.

SpitotRs305

did you actually watch pepboys test the injectors? if you didnt dont trust them test them for your self...