Question1994 eclipse, 1.8, gs, manual
I came upon this car knowing it needed work, have replaced the water pump, plugs and wires, thermostat, distributor cap and rotor, radiator hoses, and, belts. then I had to replace the head gasket, and head because it was warped, had the replacement head checked and was told it was good, and replaced a cracked rocker arm assembly, and lifters, I also flushed the engine to get all water out of the oil and replaced oil and filter. one thing i haven't changed is the fuel filter
the car runs,but very rough, and makes a tapping noise that has me baffled, along with low compression and it will not pick up speed/ won't go above 2-3,500 rpms. Everything is reconnected/ installed properly and the timing is right, yet something is still wrong and i can't figure it out, and i have been working on cars since i was 8 and am now almost 20 yet all that still ain't helping. I have mechanics who live by me and am getting different ideas (there stabbing in the dark in essence) one is telling me its the pulley, or a lose bolt but all are tight, i am starting to get so frustrated that i am ready to give up and sell it, but really don't want to. any ideas on what the cause may be? any help would be extremely appreciated, thank you in advance Matt
AnswerMatt,
Tapping noises on older Eclipses are common. If you used OEM lifters made for a 90-99 Eclipse, you will get a tapping noise. Though if the ones you just put in are new (or at least cleaned very well), you shouldn't hear tapping from those after you've run the car for a while. Loud tapping can also be caused by a bad fuel injector. You may want to try buying a new injector, then replace an exiting one with the new one. Do this for every injector and see if the noise gets any quieter for any particular injector that gets replaced. Replacing the fuel filter is a good idea, and may help a bit with the rough ride, but it probably won't solve all your problems.
Other items to keep in mind are your mass air sensor, O2 sensor and crank/camshaft sensor. A faulty cam sensor will make your computer think the timing is off and cause a poor ride and knocking. Typically, these type of sensor problems would cause the check engine light to come on, but if there is a problem with the computer itself, it may not. Read this article for more information:
http://www.90gsx.com/eclipse/cap/caps.htm
If the ECU is malfunctioning, you can have all sorts of unexplained problems. It wouldn't take much time to pull the ECU and visually inspect it for damage. But the symptoms you're describing does sound like the ignition timing is being automatically adjusted incorrectly - either due to a faulty sensor or a faulty ECU. If you really want to keep the car, and you don't have access to the factory service manual, I would recommend getting one. There are great procedures in there to test the major eletrical components, and you should be checking all the sensor to see if any are bad.
Good luck!
