JerrrrStanley

Ok, 1991 3.1 with 192k. It started surging and back firing then died and wouldn't start. Started testing to find we had no spark at the plugs. Replaced the coil pack and still no spark. Next, we replaced the ignition control module. The old one tested bad so I was certain we fixed it. Still no spark and no start. I have fuel pressure and compression just no spark. Is there a part that will go bad and fry the ICM? Also, will a bad knock sensor make a "no spark" condition? Thanks for the help in advance...I'm lost!
Another thing is there a 3 vacuum lines that are broken or melted in two. They all are on the passenger side close to the egr. Would this cause my problems too? Where is a good place to find where these vacuum lines should go? Hayes?

K-slice

iTrader: (2)

Check the dizzy?
Damaged vacume line will cause it to run bad, or not at all, but shouldn't cause a no spark condition.

Maverick H1L

iTrader: (8)

Seriously, I wish you guys would search before posting... I at least try to find some of what I'm looking for before I ask...

If you would , you would find that ignition issues are a common problem on the 3.1 cars due to a wiring harness fault (that GM issued a TSB for). There's at least a dozen posts on this a month.

Oh, and there is no such thing as a coil pack on any F-body older than 1993... It's one coil, period, for all six cylinders.

The vacuum lines are the least of your worries until you find the wiring problem.

JerrrrStanley

I have searched for the past 3 days! The problem is that it is VERY RARE that a solution is posted. Most of the post I have read are left open ended. I only have 10 posts because I cure most of my problems by searching.
Now I appreciate the info on the vacuum lines but I just feel like your goal was to kick me while I'm down. I just sold this car to my in-laws and within 2 months it has died. I only have 2 weeks of vacation and would like to have it fixed before I have to leave. So, can someone help without talking down to me and assuming that I didn't search.
Or, Maverick H1L, find me a post that has a solution to problems similar to mine or answers my questions. Maybe I just am not up to your caliber in searching posts.

JerrrrStanley

K-slice, I checked the dizzy and replaced the rotor and dizzy cap. The rotor turns so its not the timing chain. I have replaced everything to do with spark, that I know of, other than the knock sensor.

evo6z28

also I had a problem with the harness that connects the ignition coil to the dizzy, replaced it and no more problems. just something else to look at.

Maverick H1L

iTrader: (8)

Dude, if it's not firing in the first place, the KS is NOT the problem...

The IGNITION MODULE runs the engine until the engine speed hits 400 RPM. I believe I've posted this at least TWICE in the last week. If the engine isn't even trying to start and you've replaced pretty much all of the ignition system components that can possibly be replaced short of the wiring, then the wiring is the problem. The KS is connected DIRECTLY to the ECM. Not to the ignition module, and not to a secondary spark control box as on the older V8's, but the ECM.

As I've posted before, check for power at the pink wire at the coil and the + terminal on the ignition module (at the 2-wire connector that comes from the black ignition coil connector). And then check for battery voltage on the white wire (next to the pink ignition switch power wire in the gray connector) at the ignition coil's tach terminal (there is an inline connector in the white wire... Find it as it's important for checking the system). Check this with the inline connector disconnected and the meter attached to the coil side with the ignition on... If you disconnect the gray coil connector, this becomes pointless as there is no power in the circuit and you're testing an OUTPUT....

Oh, and since you didn't mention it, do a resistance check on the pickup coil in the distributor...

JerrrrStanley

Thank you! Sorry for the rant earlier. I am 300 miles from home, I don't have my tools, and the car is in a field right now. I really miss my multi-meter. Not because it is anything great, I am just used to it. I don't trust the one I'm using now or me using it. I don't claim to be a mechanic and definitely not an electrician but I don't have the money to pay someone else to do it. Thanks again for the information, I now have a better understanding of what I'm doing.