I am helping a freind with his 92 civic. He bought it from an old lady that said all it needed was a starter.

We replaced the starter. Then we were throwing a code for fuel delivery system.

We replaced the fuel filter, plugs, wires, oil and filter, air filter, o2 sensor. Finally after all of this we thought we had it fixed. Everything was working normal. We never drove it, but under no load all was normal.

Then he got insurance and tags for the car and started driving it. Well the idle went back down to about 300rpm, and in random placed in the power band it sputters and bogs very bad. So bad that going up a slight incline with it floored it will not gain any speed, no matter what gear you are in.

Also most of the time while driving it, it will not heat up, but it it is sitting still the gauge will go to normal temp. as soon as you strat driving it will start to fall back down though.

We have checked for vacum leaks and there are none.

Anyone have any thoughts???

Please help. What sensor could cause this? Anything fuelwise that would cause this?


Oh yeah, i did search

 

check for a clogged exhaust system. disconnect the exhaust between the exhaust manifold and cat. if the car drives great with just the exhaust manifold, then you have a clogged cat or something else down the line. you may have a water pump that needs replacement, or a thermostat that is not closing which would cause the cars temperature to fluxuate like you describe. it would also be wise to check ignition timing and your spark gap, dist cap and rotor and injector firing pattern.

 

there is no cat. the old lady's son got ahold of the car. plugs were checked when we put them in less than a week ago. Cap and rotor both visually look good too.

 

If coolant by-pass was done I would undo it and that should fix the temperature issue especially in colder climates.

 

time for a compression test, cam timing check, ignition timing check, valve lash check.

 

here is a lil more info on the car. i dont know if it will help or not, but its worth a try. oh its my car by the way.
sometimes the car will find the right combination or rpm and throttle pressure/fuel that it will run good. the engine in the those few moments feels strong (as strong as a d15 can anyhow). the car seems to do better when im light on the throttle. it doesnt stutter as much. it accelerates smoothly then and will cruise at a steady speed nicely then as well. but any change in throttle pedal pressure will cause it to stutter and bog again. if i try to accelerate moderate to fast it bog and strutters horribly until higher rpms. the point where it stops bogging will vary, sometimes 3k sometime 4k sometimes 5k.

we will check the timing tomarrow.

thanks guys

 

check tps, map, o2 sensor outputs. check ignition condition with meters.