94 deville after tune up starting problems ... please help

Hi there everyone, thanks for looking.

I'm very mechanically inclined and have been working on vehicles for a long time, but I have never run ito this before ...

I have a 94 deville that Ive had for about a year. I decided to do minor tune (plugs, wires, cap, rotor, and air filter). As always, I did plugs and wires one at a time ... I did the front 4 and decided to call it a night, but it was backfiring through the intake. I checked and rechecked the firing order ... and its correct. Since it wasnt runnnig right I decided to do the other 4 plugs and wires ... agian one at a time and again double checking firing order.

Now it wont start. I have not messed with the distributor, I threw in a new coil assuming I could have in my haste damaged it ... and still nothing.

Im sleep deprived and missed work today ... any ideas would help and be greatly appreciated. I drove it in!

Thanks everyone. Oh, also the trans wont shift in the morning until the car has warmed up for a few minutes. Has been that way since I got it. It hasnt got better or worse. Is this a bad thing ... any ideas?

You say you checked and double checked but I still think you screwed up the firing order somehow. When standing in front of the car looking at the engine the front 4 cylinders from left to right are 1-3-5-7. The back 4 are 2-4-6-8. The spark plug wires are numbered on the ignition coil cover, but #1 generally is directly next to the air filter and going counterclockwise the firing order is 1-8-4-3-6-5-7-2. Hopefully this helps.
Another idea is that you put the rotor on 180 degrees backwards. The rotor should have a notch in it so it only goes one way but maybe its still possible somehow to screw it up.
Let us know how it goes.

Did you get the ground strap under the coil back in correctly?

Also check that the power connections to the distributer are correct, and tight.

I did install the coil correctly, I thought it may be bad (didnt have a meter handy) Bought a new one and installed. Still have same problem. I was aware of the firing order ... same as most sb gm cars and I also had looked on the intake to verify the cylindar numbers. The connections to the distributor are like the rotor ... notched and only go on one way. I didnt force anything into place or forcefully remove anything.

I am going crazy on this one ... I dont know if I originally put them out of order ... then cranked it over and had backfire ... could this cause the timing chain to jump? or maybe a wire got disconnected on the harness? I am thinking about tearing down to check the chain, but I still just dont see it being the problem. It has to be something simple Im overlooking.

I really appreciate all the advice and info ... I will keep trying and let you know when I get it running. Maybe Ill tear it down anyway ... it does have nearly 280K on it. (nice car ... ran good before I touched the plugs and wires :( It was a traveling sales car ... almost all highway.)

did you see the numbers on the distributor coil cover? #1 is the closest one to the left front (driver's side) tire.

ok, I charged the battery (it was dead from me cranking it over) and the thing started up ... runs like poop though. I jumped the a&b pins for timing set mode, grabbed the timing light and set it to 10 deg BTDC, it runs a little better, the timing mark was moving back and fourth pretty rapidly ... if I put it in park or neutral and rev the engine, it smothes out a bit, but does not hit higher rpms ... it seems to choke out or have a rev limiter on it or something, but seems to only be in the 3-4k rpm range.

The cooling fan (on the radiator) does not seem to be engaging.

Im going to drive it to the store and see if it does any better ... Ill post my results tomorrow.

Thanks again everyone for the help and ideas ... I wish I had a definate answer to what was/is wrong ... I dont know if anyone else has had similar problems.

Hey there guys ... drove the car and it is still pretty rough.

Idle is rough, seems to run rather smooth between about 1500 to 2500 rpm. No guts going up hills or taking off.

The cooling fan does kick on, but didnt when I was sitting still in the parkinglot when it decided to start. Maybe I didnt let it run long enough.

I think I had the firing order going clockwise, not counter clockwise originally.

The parts store told me the gap was .060 is this correct? Would incorrect gap cause it to run so rough? I did set them all prior to installation.

The parts store told me the gap was .060 is this correct? Would incorrect gap cause it to run so rough? I did set them all prior to installation.


Yes, that's correct. It will also be listed on the emissions label. I don't think a smaller gap would cause it to run rough, but a larger one would.

I got it running well now ... turns out in my haste, I didnt tie up all the plug wires or run them through the "loom" ... 2 wires rested against the manifolds and burnt. I replaced the wires (again) and this time routed them as they should have been in the first place ...

She runs great again with more power than I have ever had.

THANK YOU ALL.

ALL RIGHT!!!! Good to hear