If you set the timing, go by what’s on the underhood sticker as that takes precedent over anything that may be in a service manual and so on.
Engines that use computer controlled ignition timing almost always have a test plug or connector that needs to be either jumped or grounded so make sure that is done first.
Otherwise, the timing will not be anywhere near correct and if too much timing advance is allowed there is the possibility of engine damage at higher speeds and out on the open road.
Glad you got it running again. It does indeed sound like there may be a tps problem. The service manual will say how to test it. There’s a slight chance the accel problem could be related to the egr. The egr activates more when you step hard on the gas, but doesn’t if you accel gradually. Not all cars have egrs, but if yours does, consider that too.
On hard to start and runs poorly problems, always make sure the engine is acting as a sealed unit. There can’t be any air leaks between the air filter and the exhaust pipe, otherwise it will confuse the computer and it won’t know how to adjust the mix correctly. You’ll go from running rich to lean all the time. Common sources of air leaks are split vacuum hose, split diaphragms in vacuum operated devices like the brake booster, and problematic idle air control gadgets. On the exhaust system, cracked exhaust manifolds, leaking exhaust manifold gaskets, rust holes anywhere in the exhaust system, especially early in the exhaust system, closer up to the engine.
On some engines of this era there’s an idle air bleed screw, used to set the final idle rpm during a tune-up. It is extremely important this isn’t used to compensate for an air leak somewhere. 'cause if that’s done, it will be near impossible to get a correctly running engine. The symptom if the air bleed screw is out of range is usually an engine who’s rpm wanders around, but almost anything can happen. If your car sports one, the factory service manual will say where the nominal position of the air speed screw is, usually around 2 turn out from where it seats.
Actually, the egr is not supposed to activate upon wide open throttle
interesting … It sort of makes sense, if you step as hard on the gas as is possible, you presumably are doing it to pass or for some emergency situation like there’s a big truck coming toward you, so you want all the engine power available at that point. I guess that’s why throttle position sensors sometimes have a separate switch position to sense for a wide open throttle condition … so the ecm can sense that and temporarily disable the egr. Could still be a clue to the OP …
Today I drove it around the block and it handled well! It gets some good power and drives nicely.
I used a timing light to adjust the ignition timing, which helped a lot with the accelerating problem. It was off by about 18 degrees! so after bring it back it was much more responsive. I did have to jump the pins on the data connector, pins 3 and 5 I believe on a California emissions, which has 6 pins instead of the usual 4.
However, it will still stall when I rev it and quickly let go of the throttle. I believe my TPS needs adjusting, because while I don’t have the CEL on, I do get an error code which states the idle switch circuit is open or misadjusted. This might have to do with a K&N filter I put on?I ripped out the old filter housing and put in a cold air intake, so could this do it?
The TPS can be adjusted using my service manual, I’ll be trying that sometime this week. Another thing which might affect it is the position of the throttle cable. I had to draw it in significantly, making it tighter on the throttle to get the car to start. It was originally about half the distance possible, I made the cable as tight as it would go. Though it still doesn’t apply any pressure on the throttle without the accelerator depressed. Another potential issue?
Thank you all for your help!
If the balking doesn’t go away after any work with the TPS switch you might consider the possibility of a MAF sensor problem, intake vacuum leak, or leak in the intact tract between the throttle body and MAF sensor.
Whether the K & N has caused a problem I do not know. You might consider unplugging the MAF and taking a quick test spin to see if the balking goes away. The CEL will illuminate of course but it’s not a worry as this is only a test. If the balking disappears you might consider a MAF problem or air leak as an air leak can affect what the MAF does.
Good thing you got the timing sorted out. Eighteen degrees too much advance or too much retard can cause all kinds of grief; sometimes expensive grief.
Make sure the idle rpm is at spec. If the idle rpm is off that can make the ECM mistakenly think the tps isn’t working correctly.