Gremlins

[neanderpaul]

Looking for advice....

Gremlins

96 aspire 5 speed. OBDII.
Driving fine. Slight idle variation. Occasional puff of smoke on start up. When daily driven check engine light went off. Left sitting for 6 days check engine light came back on.

In one day the following things were done to correct the smoke, idle variation, and CEL. Valve guide seals, plugs, wires, distributor cap, rotor button, PCV valve. During this process we ran a jumper wire on the "diagnostic port" in the engine bay. I did not realize this was an obdii car before Nate found the plug under the dash. This turned on the cooling fan.

During the valve guide seal process we had to remove the throttle body and the idle air control to access the valve guide seals. Gasket on the throttle body tore some. Nate sealed it with RTV. Later Nate cut a gasket for that to eliminate that as a possible point of failure.

Upon completion it fired right up. Idled smoothly with no vibration. Listening at the exhaust there was an occasional low frequency misfire.

Test drove. Pushed in clutch and brake. Idle stumbled to 400 rpms. Accelerated hard. Drastic loss of power. Pronounced pinging detonation.

Testing:
Sprayed carb cleaner over every possible point of vacuum leak. There was no increase in RPM.

Removed brake light switch. Depressed brake pedal. No change in RPM. Activated brake light switch. RPMs dropped.

Operated lower clutch switch without operating the clutch pedal. No change in RPM.

Replaced brake light switch.

Tested timing marks with a timing light. 2 marks on the pulley were counterclockwise of the stationary mark. Retarded timing at the distributor to the maximum and got pulley mark on time with stationary mark.

After timing adjustment rpms did not drop with pushing the clutch and brake pedal. Pinging nearly disappeared.

Tested throttle position sensor and idle air control. Both showed good readings.

Check engine light went out for a time after initial post tune up start up. Check engine light came back on. Got the OBDII scanner.

It said throttle position sensor.

After that all grounds were disconnected, cleaned, and reconnected.

[tooldude]

While not the expert, I'll throw out some ideas. The starting point in any computerized system is to establish sufficient battery voltage. Low voltages can cause strange problems. The 94-95 is typically OBD-I (2 digit codes) and 96-97 is typically OBD-II (4 digit codes), which do you have? You need to know the engine control strategy for that vehicle before you can make much sense of the symptoms. Because there is a hierarchy of tests within OBD II, the TPS code may only be telling you that it doesn't jive with another input, such as CkP sensor (the same way an O2 code doesn't necessarily mean a bad O2 sensor). However, since you should have OBD-I, the TPS may be testing OK, yet the signal not getting to the PCM. The PCM may be in fail-safe mode (FMEM). Fully retarding the distributor is compensating for advanced timing which seems to indicate a problem with the advance system, or maybe being in FMEM. I would check factors that affect timing, CkP, ECT, IAT, MAF sensors, & timing belt. The brake switch, when on, sends a 12V signal to the PCM which affects the deceleration system, so RPM drop may/may not be normal if in FMEM. Did you set timing by the book, grounding the STI connector, matching the yellow pulley mark (10* BTDC); reconnect the idle switch connector; reconnect the IAC connector; have the right crankshaft pulley (& marks) not spun on the crankshaft?

[Prafeston]

Sorry, AMC fan here. So when I see Gremlin. I just think...

[M3NTAL]

Is it still low on power? Have you ruled out dirty injectors ?

[iriegnome]

I am an AMC brat myself. Dad worked 37 years at the Motors. I had 5 Gremlins over the years. Including one just like in the pic. A 1975 Made in Mexico 3 speed on the tree White with Orange stripes and interior. I loved my Gremlins. Not so good for the OP though

[bravekozak]

Sorry, AMC fan here. So when I see Gremlin. I just think...

There is one at Airport Auto Wreckers in Niagara Falls, NY in the south west corner of the yard. I will take a pic of it for you next time I am there. I must warn you, ahead of time, that it does not look quite like the picture that you supplied.

[walth]

Does the OBDII aspire have a knock sensor?

[nitrofarm]

Hey Paul on my 95 5 speed Aspire my brake switch works just the opposite.When I push on the pedal the idle goes UP because of the load compensation solenoid. So why yours is going down is strange. Now on my wifes 97 I've had a CEL for a year now.It gets 30 mpg all the time runs great when you want to go fast and doesnt ping. I gave up on the CEL after taking it to local parts stores for scanning. Everyone of them just shrugged & said it wont work??? I'm considering buying a SCANGAUGE 2
Look at post 8 for what I'm talking about http://www.fordfestiva.com/forums/sh...153#post641153
I can get my 97 CEL to clear but it always comes back after a week.I kept telling my wife to tighten the gas cap after refuel.But that didnt help either.
Oh and one other thing on setting the timing and base idle.It really helped on both of mine to let the cooling fan come on twice before I grounded the sti. Not much help I know but thats all I got for ya,good luck-