my quad 4 is running on the 2 inside cylinders and I already changed coils I was wondering if anyone had this happen . Its a 1995.
Michael

well then that would make it a quad 2 then wouldnt it? a little more info would help... was it rebuilt? if so, how many miles? do you have fuel to all 4 cyls? did you check the spark on all 4 cyls? any more info would help.

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1986 Silver 5 speed Fiero 3.4 DOHC
Bored .30, Fully balanced and blueprinted
13.93@101mph as it is on the street.
... ... !
350ci 400hp/tq SBC, 4 bolt main
Spec Stage 3, Nitrous Oxide, many extras.
87 GT 5-speed Getrag, power everything.

[This message has been edited by flames4me (edited 05-02-2007).]

If it feels like it's running on 2 sylinders it probubly is.Check your fireing order again...

(might also be the wires arn't snaped on right).

It only has spark on the inside cylinders and it doesnt have wires. I was driving down the road and 2 cylinders quit. still gets fuel to all cylinders

Check out the boots under the top engine cover they often split or come loose or just plain stop working. They don't seem to last as long as a coil pack setup because the heat from the engine gets trapped under that cover and also they are subject to vibration more so then a regular plug and wire style ignition. Lots of guys convert their quad's to coil packs for this reason.

Do you know which two are not firing?

The injectors are paired up as 1+4 and 2+3
and the Coils are 1+2 and 3+4.

So by pulling injector clips you can find which cylenders are or are not firing, and potentially why.

If it is ignition related, meaning either pair 1+2 or 3+4 are not firing, then your only recourse is to replace the coil's or the ignition module or the spark boots. The crank signal goes directly to the ignition module, and the power to fire the coils, then the ignition module actually fires the coils. The ECM has 4 wires running to the module only to help it control timing. So that leaves you with the ignition module not working on one output, or the coil has crapped out. These items have a high rate of failure anyway, so it's not suprising if its one or the other.

If it is fuel related, it can only be either the wiring or the computer. The ECM does fire the injectors at the same time, but it uses two seperate circuits to do it, if one fails, you run on either 1+4 or 2+3.

I replaced the coils and plugs and no difference. I then turned the engine cover with plugs and coils all assembled upside down ,grounded the plugs, and cranked it over and only the two inside plugs fire.

did u replace wires too??? switch your wires...take one that is working and put it on a plug thats not firing..tim

I had a problem like this with a Saturn "Quad4". The injectors stuck open. So it was getting fuel to all cylinders and the ignition was working... it was just getting too much fuel.

Try some Seafoam?

quote Originally posted by Mlevair: I replaced the coils and plugs and no difference. I then turned the engine cover with plugs and coils all assembled upside down ,grounded the plugs, and cranked it over and only the two inside plugs fire.

Based on this I think I'd try a different housing i.e. the white or black plastic piece that the coil packs fit inside.

You also might want to try not grounding the two inside plugs and see if the outside ones then fire.

[This message has been edited by sanderson (edited 05-03-2007).]

It's not fuel related, he already said he's only getting spark on the inside two. And the Quad 4 doesn't have plug wires.
Did you try replacing the ignition control module too?
(It's bolted to the inside of the IDI cover)

I thought of that but they wanted $168.00 for it and I wanted to get some advice before I bought it.
Michael

Go to a junkyard (preferably a u-pick-it), and get a few ignition housing complete with the IDI cover, coils, housing, and ignition module, since you are a '95, I think your ignition module is a one year thing, but everything else is the same, and swap the entire cover across and see if it makes a difference. If you get a non 95, just change the ignition module. Also, one coil fires 1+4, and the other fires 2+3, not 1+2 and 3+4, so that means you have a dead coil, or a break in the line from the coil to the plug. Them plastic housings have the plug wires built into them, and they often go bad and arc across to the cam towers.

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84 Fiero Sport Coupe #1192 :: 86 Fiero Base Coupe Quad 4 HO :: 1998 Dodge Neon EX 2Dr 2.0L DOHC Auto

more than likely it is the coil housing or whatever it is called they do go bad. I had to replace quite a few om them when I worked at the Pontiac dealership many years ago. The coil was the first thing to fail with the housing not far behind.

thanks for all the help to all who replied.
Michael

On a possibly related note...You might want to consider switching from the Quad4 coil-on-plug system (notorious for coils and the housing going bad) and moving the ICM and coils elsewhere...this can be done with an ICM and coils from a 2200 (the ICM wiring is even color-coded the same IIRC).

I used to have a page with instructions (it's very easy to do) but apparently it's been deleted

[This message has been edited by Captain Colon (edited 05-06-2007).]