87 ea82 spfi component check, and ECU code questions

[daeron]

Okay.. ever since i got this car it has seemed to have an odd erratic power problem.. now, ive tightened a few clamps (like the one where the intake boot goes into the throttle body, whoops!) and fixed a few things like the thiming belt, and i think a possible wobbling crankshaft acessory pulley, and its improved a bit.. i still need to do the whole plugs wires cap rotor thing, but the wires are not TOO old (~30,000 miles? not OEM at least) and the same for the plugs..

 

I also need to do a compression check, and a bunch of other things, but there are symptoms that are still to hazy for me to try to communicate (this is a VERY erratic problem, made hard to determine by the fact that i have the AT slushbox in it...) but i want to check all my FI components (AFM, TPS, etc..) I have downloaded the 89 loyale FSM (well, the chunk of it) that floats around here, and it has the FI info in it, but i havent pored thru that yet.. im about to now. My question is...this link in the USRM tells me all about checking ECU codes, and im wondering if i might have any to check, even though i have NEVER had a CEL on this car? (well, once, but that was because i plugged in the green timing check plug under the hood thinking, hey, it should be plugged in, right? and drove it.. then i found this forum and found out what it was :- / ) Im beginning to think that my TPS or my AFM might have an issue.. that, or i need to do a more thorough check for vacuum leaks, or something...

 

but it could be a number of things. I dont get much time to do anything remotely mainline (like compression checks etc..) because thats all at my family's "shop" and not at my house... so im doing alot of skull work on this when there are already a few key steps (tune up and compression check, and a coolant flush) that i really need to just do.. But im trying to check something out, yanno?

 

thanks for reading the rambling post.

 

shawn (carey, not the admin.)

[NorthWet]

Before you go too wild, take care of the spark plugs/wires/rotor/cap. I have witnessed all sorts of bizarre power issues on my EA82Ts that have been because of marginal plugs and/or wires. You can have full power and responsiveness through part of the power band and then have it fall flat on its face for a couple thousand RPM and then scream like a Banshee again higher up. You can't tell much of anything until you have it electrically tuned-up. (Except for that checking of stored ECU codes, which who knows how old they are.)

[daeron]

yah, i finally got around to my ignition tune-up, and am reading thru the partial FSM pdf that floats around.. i forget where i found he link before anyone asks, and i could send it.. maybe, somehow, but its big.

 

it seems a bit beyond my grasp at first perusal, but im sure if i print the pages out and go thru the procedures step by step i should be okay... and anyhow, my point was that i wanted to know about trouble codes being possible (under the radar) so to speak... because if there is a more comprehensive self diagnosis mode to put the computer in before i go doing the compnent checks, I would far rather do that.. im trying to plan my attack as thoroughly as possible, because i really dont get alot of free time to work on this thing. so, i ask before i had done my plugs etc, and said yah i know i need to do those first, and took that as a given, and assumed it probly wouldnt fix my problem because the problem is more shirty than that. However, there are times when i say, approach a left turn in a divided highway.. pull across one lane of traffic, and kinda coasting to double check my aperture before pulling in front of people, and then i hit the fuel pedal and the engine almost totally dies for half a second, then wakes back up. This is is only symptom of any problem ive experienced that i even really understand enough to BEGIN to relate "what my car is doing.." as i said, there is something sneaky going on with either spark or ignition, or something...

 

but before i go into any long FI compnent testing procedure and probly rip my entire intake off to test it bit by bit.... i want to be sure i have to do that. I want to figure out why im running a little hot (sparks where white when i removed them, but no inordinate physical wear so to speak..) i want to check compression and do a leak-down test (if needs be) and i want to shoot the timing, and get that set perfect. i dont think we ever timed it with a light (my brother and I) and so its "pretty close.." which can only be pretty bad. At the very least, something is causing me to spit a tiny tiny bit, but almost constantly at idle...

 

 

so can i really just plug the test mode connector in with the engine running, and look down to my LED and see if i have any ECU-detectable compnent faults? or do i plug it in and start it, and it does it, or what? i read the tables, and they state a given scenario (engine on, this one plugged, this one not) they dont say plug it together, then start.. or start, then plug in.. or am i interpreting this the wrong way? is this "test mode connector" simply just a way of identifying a present (or past) CEL? because i have no CEL on my car, and never have, except for once when i plugged both those connectors in thinking hey that stuffs unplugged, that can be good, huh?.. then realized exactly what they must be when the car didnt run quite right and the CEL started flashing at me....

 

I will read thru the FSM over again when im not so close to catatonic, but a *tiny* drop of somplification would be appreciated. somehow, i find that interpreting technical writings like these FSMs are is much easier in hard copy, so i need to print that page range out.

 

ohh god, just looking at it on the screen for so long has my head splitting. I think i can figure this out, but if anyone wants to make it any easier, or if i am misunderstanding something i am reading and you think you might set me straight, id appreciate anyones feedback..

 

shawn