Hey,

My '96 EX has a check engine light. Took it to my mechanic, he said the code was "Engine running lean". I replaced the fuel filter and the light AND problem went away for a while...but it came back with a vengeance yesterday. The car will randomly hesitate and sit at about 2000-2200 rpm even with the pedal to the metal. Sometimes I can drive it with zero problems, sometimes I can barely get up to 35 mph without pumping the pedal. The other day it was also hesitating oddly on the freeway at about 60 mph...felt like someone was tapping the brakes on and off. I took surface streets home. (That was before the fuel filter replacement.)

Any suggestions?

Thanks.

~Micah

 

I would start with fuel pressure readings before replacing any more parts.

 

Will the fuel pressure readings be off if it's such an intermittent problem?

 

That's what makes intermittent problems so difficult to diagnose, they are intermittent. If the fuel delivery is the problem I would suspect an issue with the pressure regulaor, pump or possibly an intermiettent voltage drop on the main relay.

I found a crack in the fuel pickup in the tank in a customers car once. The pump would draw air into the fuel system but only when the tank was nearly empty. Otherwise the car was fine. I've found a couple of faulty fuel feedback sensors ( o2 sensors ) which were causing a car to run horribly because they were biased.

The point is there are a lot of things that can cause your symptom. Make sure you only let the most experienced technicians try and figure this out so you aren't dumping a bunch of unneeded money into your cars problem.

 

Hey thanks so much for helping me so far. Here's the information from the code reader's freeze frame:

Error P0171: System Too Lean (Bank 1)
Freeze Frame Data:
Fuel Sys 1: CL
Fuel Sys 2: CL-Fault
Calc Load %: 76.47
ECT (degreesF): 172
STFT B1 %: 46.88
LTFT B1%: 19.53
MAP (inHG):23.03
Eng RPM: 2334
Veh Speed (mph): 31
IAT (degreesF): 75
TPS %: 23.92

I just finished spending too much money on a timing belt job and a new radiator for this car...I can't afford to have the shop charge 100 bucks an hour for diagnosis. I'd like to try and narrow the problem down myself, if I can get some suggestions on what course(s) to take.

Many thanks again.