Anyone had this misfire issue?

[my1stgn]

So I just had the alarm put in a few weeks ago and now the car has an intermittent misfire problem. It looks like it fires only on half the cylinders and on my Trans Gen II it shows 0 RPM when the car misfires. I took a temp gun to the cylinders to find out which ones are misfiring and it looks like only 1 cylinder per coil pack is firing, so I have 2 cylinders on one side and 1 cylinder on the other side that are firing. I am thinking either the ignition coil module took a crap cause I doubt that all the coils would go bad at the same time.... right? Im gonna double check the work the alarm people did but I do not want to take it back to them to check it out. I wouldnt trust them to diagnose a car even if its just double checking there work. I would rather do it myself.

But sometimes the car runs fine. Then other days I start it and it misfires like crazy! But it only misfires on start ups and then I cant drive it. If the car starts normal then usually I can drive it with no issues.

Anyone had this misfire issue before? Thanks!

 

[meanchicken]

Installers probably nicked up your wiring under the dash assuming it's related to the alarm install.
Trace the wiring under the dash from the instal and see if anything looks boogered up.

....but they'll deny everything...

Have you checked out your coil pack and ign module yet?
Is your gin module bolted down tight?

Is it doing it at idle?
Unplug your MAF and see if it goes away...

Battery cables and connections all tight?

 

[my1stgn]

Good Points! Im gonna check all those out.

Another things that happens when this problem is happening is the check engine light flashes real fast. Not like the "hey you have a huge misfire" flash like on the OBD II cars, but faster, more like a "something is shorting out" kinda quick flash. And this is before I even try to start the car.

So when I turn the key to the on position, the check engine light flashes real fast and if/when I try to start it the car misfires bad.

But if I turn the key on and the check engine light is off, the car starts fine. I havent looked to see what code it is for the check engine light yet.

 

[turbolou]

Reply

Good Points! Im gonna check all those out.

Another things that happens when this problem is happening is the check engine light flashes real fast. Not like the "hey you have a huge misfire" flash like on the OBD II cars, but faster, more like a "something is shorting out" kinda quick flash. And this is before I even try to start the car.

So when I turn the key to the on position, the check engine light flashes real fast and if/when I try to start it the car misfires bad.

But if I turn the key on and the check engine light is off, the car starts fine. I havent looked to see what code it is for the check engine light yet.

Chickens recommendations are good but check to see if the installers tapped into any computer wiring. The orange power feed wire to the computer is a favorite for them to tap into since it appears easy to do. Also a bad or improperly installed chip will cause rapid flashing of the check eng. light. Make sure you haven't any bent pins on the chip.

 

[750H.P.V6]

I'm with Lou. Check the chip installation. If it looks OK try another chip. Sometimes they crap out and you'll get a flickering check engine light and the car will barely run.

Neal

 

[Rodney87GN]

^^^Good suggestions above. I would also look for corrosion on the ECM pins. I've personally experienced this and my car would do weird sh!t intermittently until I replaced the ECM...you'll never be able to completely clean the corrosion off the pins.