How To Test Ignition Module + Possible Car Trouble Relation

MR · 06-22-2005, 04:11 AM

How would I go about testing the ignition module?
As far as I knew, I could test each set of prongs that connect to the coil packs. This reading would be ~ 1.5Mohms.
I saw this somewhere, but I can't find it again.
Is this correct?

I actually have a problem with my car that this could be related to.
It's a '92 SL1 manual.
Almost 190k miles on car, but almost completely rebuilt engine at ~ 150k.
Changed bearings, seals, all but the piston rings and timing chain. Stupid mistake, but that's what happens when you have no money.

Just yesterday, I pulled away from a stop sign and I heard a noise that sounded like little bb's inside a tin can and the can was being spun really fast.
It went away after about ten seconds and after that the car was very sluggish whenever I would floor it.
I can hear the 'rattle' if I use light throttle pressure where engine is ~ 900 RPMS.

Whenever I really get on it, the car will not redline in any gear and is very sluggish in accelerating.
I can only redline when I gradually give it gas.
I also noticed if I goose it hard when the car is stopped, I can make it go past the idle limiter, but the idle limiter still works.
Coil packs are fine. Fuel pressure is fine. O2 sensor is fine (I think, I changed it and even disconnected it, but that didn't solve the problem).
It did throw a FLAG 53 which is the Knock Sensor, but I cleared it and it didn't come back.

Anyone know what's wrong?

**Ssicarman** · 06-22-2005, 05:06 AM

Is the noise external to the engine or internal? Try removing the O2 sensor to see if the engine will accelerate any better. If it doers then the cat converter may have broken up or plugged up.

Engine runs ok at idle?

MR · 06-22-2005, 05:29 AM

Engine seems to run just fine at idle.
Noise seems internal.
I disconnected the O2 sensor and then drove the car, but the problem did not go away.

**Ssicarman** · 06-22-2005, 05:44 AM

Not disconnect the O2 sensor. Remove it to see if the hole in the exhaust lets the exhaust out if the exhaust is plugged. Don't drive/run to long like this as the hot exhaust will damage things. With the noise internal to the engine it may not be a plugged or restricted exhaust. May be a timing chain? Where then t-chain parts replaced with the rebuild?

MR · 06-22-2005, 06:04 AM

Ok, then no, I didn't leave the O2 out to check for pressure.
But I was able to check the exhaust pressure while keeping the car at ~ 2500 RPMs and it seemed fine.
I also noticed a miss in the exhaust at times.
I actually had to engines to work off of for my rebuild and I picked the best timing set.
I did have a scan tool hooked up to it and it showed a 40 degree timing advance AND a 2 degree retard at the same time I think.
there were 2 things that didn't seems to make sense, but I can't remember what they were, since I wasn't the one looking at the scan tool.
Also, if I floored the car for more than a minute, it would stay about 1500 RPMS below redline and then cut the fuel off until the car decelerated about 8 MPH.
For example, I put it in 2nd, floor it, car stays ~ 50 MPH, fuel cuts out, car slows to 42 MPH, then car accelerates again.
This process can be repeated forever.
As soon as I let off the throttle a little and then gradually give it gas, the acceleration becomes almost normal (still a little slow).

Sega Saturn · 06-22-2005, 09:39 AM

Check the knock sensor, this sounds very close to what I experienced one day. The bb noise is detonation, not good, it was a hard thing to find but this is what it was, its located under the engine on the fire wall side, its a piezo crystal sensor so its a bit pricey, my dealership had specs for the resistance values, find out what yours is in relation to whats specified.