1996 Z24

Got to work one day and the car was running like crap right after I got off the highway. I took it by an Auto Zone after work and the codes were: Cylinder 3 misfire, Fuel Injector Circuit Open, and Evap Emission Control something or other. I figured the injector died on cyl 3 which was causing the computer to see a misfire. I ordered a new injector.

A week later I put the injector back in, put everything back together, start the car, still runs like crap. I pulled out the plugs and number 3 looked kinda white like it was just sparking and not getting any fuel to cool it. I put in a new set of plugs, and it still runs like crap.

Today I had my wife prime the ignition while I checked voltage at each fuel injector's connector. They all would go to about 11.4 volts and then go back to zero. That means they are all getting power. When the car runs it smells rich. So it seems like it isn't firing the plug now. I pulled the plugs again today and 1, 2, and 4, are just slightly gray and 3 looks brand new like it's hasn't even fired once.

I took the coil cover off and tested the resistance of the coils. They are both in spec according to the haynes manual. It says .4 to .8 ohms for secondary resistance but mine both sometimes drop to .3 ohms but I believe they are fine otherwise the car would have more than one cylinder not sparking. The primary resistance was around 5500 m Ohm's so it's in spec.

Went to Auto Zone again and bought new plug boots. Asked them to check my module that I brought with me, but they said only one store has the right plugs and it's quite a drive from where I live so I just came back. Put the boots on, put the module and coils back in the housing, and bolted it up. Start the car, and it still runs like crap.

I'm wondering if somehow the coil pack housing (yellow piece with the 4 terminals for the boots) is bad? Is there a way to test this? This frustrates the heck out of me because I hate being down to one car so I would like to fix it for my wife.

On a side note, the torque convertor has been deciding it doesn't want to lockup now, and also the cruise control quits working after like 30 seconds. I'm hoping those are related to the problem with it not running right and maybe the computer is preventing the lockup from engaging so it won't make the engine struggle harder than it is. I've only driven it maybe 20 miles since it started running bad because I had to get home from work.

Any ideas what to replace? I'm already out $90 for a fuel injector which may not have even been bad. I almost bought a new computer from a parts yard today but decided to hold off. I can get a coil housing cover for $45 and the coils are like $35 each but I don't want to buy another coil and a cover if it won't fix the problem because they can't be returned once installed.


Scott
2002 Audi S4, black
1996 Z24 auto, red

I had the same issue turned out to be my pcm was f'd up

that yellow strip that holds the plug boots is a fairly common part to go bad. check the resistance from the coil to the boot connector in the housing.

I´ve changed the coil pack housing 3 times, that is the guilty part for your trouble I would say and I am 99% sure about it.

I had the same problem...changed plugs, wiires, coils, module, everything and i was still running on 3 cylinders. Turns out my ECM was toast.

I would check compression on your cylinders,could be that the plug is firing but a burned vlave or something is preventing enough compression for the cylinder to put out any power. ( I have been there, not on a J body) check all cylinders and compare readings.

I have also had the ignitions coil packs and coil housing thing fail on my 96 Z24, makes car run like sheet and all the ohmeter checks pass just fine. Took to dealer as I didnt have time to fork with and didnt want to shotgun-got the 500 dollar plus ouch! should have just bought the coil packs....

Go to a junkard and fork over $40 for a complete coil housing assemply and slap in on there and see if it helps....

I've had to do that several times..... I'm already on my 4th set of coils..... and I have more IDI covers than I know what to do with.

Changed the coil housing today. Still runs like she-it. In the last week I've put in 4 new plugs, new plug boots, and a new coil housing. The #3 injector is brand new also. The car hasn't left my garage in over a month and I'm a little upset that it will not run right. My wife wants to tow it to a shop but I don't want them to pay for something I can fix myself.


Scott
2002 Audi S4, black
1996 Z24 auto, red

Also I have another Z24 engine (original from my wifes car that a dealer told us the crank was broken... liars. So we bought another engine) and it has good module/coils/housing but it's in MI and I now live in OH.


Scott
2002 Audi S4, black
1996 Z24 auto, red

Are all the sensors good?IAT,IAC,TPS,MAP?If so it just may be your ECM



15.2@89mph 2.171 60ft. 9.830 1/8 R.I.P. "LULU"

IAT is not very old, couple of months at most. The IAC and TPS should be good, never had hesitation or idle issue. MAP sensor I don't know but I don't think it would cause it to run on only 3 cylinders.

I'm debating about spending the money on a computer, if it won't fix the issue, there's more money wasted.

What gets me is everything runs in pairs. The injectors fire in pairs, the coils fire plugs in pairs. Yet only one of my cylinders isn't firing. So either one half of one coil is bad, or I thought the internal connection in the coil housing for #3 was bad (but apparently isn't). To me it seems like maybe I should get a new coil on the side that fires cylinder 3.


Scott
2002 Audi S4, black
1996 Z24 auto, red

any new ideas since the housing didn't fix it?


Scott
2002 Audi S4, black
1996 Z24 auto, red

Where is the computer? The book says under the airbox but there is nothing there. I think I saw it between the door and fender when I had the fender off. How do you remove the computer?


Scott
2002 Audi S4, black
1996 Z24 auto, red

Get the Ignition Control module tested, sorry it wasn´t the coil housing when mine failed I lost two cylinders and car barely moved crawling and the auto trans was acting funny too, it all wen´t away after new coil housing, coils and ignition control module.

ecm is in the passenger side fender, all the way up front.



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I am going to buy a coil tomorrow and swap one out. I think if the computer was bad it wouldn't run at all. Also if the Ignition Control Module was bad it'd probably run on two cylinders and not 3. The only way I can see only 1 cylinder not sparking is if half of one coil is dead. The car wouldn't smell like fuel if all the injectors weren't firing.


Scott
2002 Audi S4, black
1996 Z24 auto, red

Could the injector be stuck open is the plug white and smells like fuel? Thats something to look into even though the injector is new.Check the wiring could be shorted to ground causing the injector to stay open which would cause the plug to be white and run like crap. It happened to me before.

It turned out to be the computer. It runs great now with a new computer. Even shifts smoother and my problem with the knock sensor not reading is fixed too. I guess my computer was really screwed up.


Scott
2002 Audi S4, black
1996 Z24 auto, red