rithsleeper

I had to switch to a remote coil HEI unit from a camaro to get it to fit with the stealth ram and I think something is wrong. I finally got the engine to fire and it runs really rough. The ECU is a Holley Commander 950.

The really weird thing is every other cylinder is firing. 1 no, 8 yes, 4 no, 3 yes, 6 no, 5 yes, 7 no, 2 yes.....

This seems like the coil is only firing every other cylinder and thinks the engine is a 4 cylinder for some reason. The RPM seems to be registering correctly around 1400 and varries so I don't think it is a reference problem....

I am pretty sure I have it wired correctly. the 4 pin connector was different but all wire colors were the same so I just matched them up. I have a power to the coil, tach reference then the two wires from coil to the distributor. It just seems too much of a coincidence to not think it is something with the EFI. This ECU worked perfect on the engine I took out though.

I set the distributor at TDC, checked lots of times and placed the 1st plug directly over where it was pointing, then once the engine started I had to advance the distributor farther than I expected to keep it from dying. The number one cylinder wont fire unless I retard the timing till I believe it thinks it is the #8 cylinder... Just so weird.

Hot Rod Roy

It's not clear to me what you're saying here. How did you "set the distributor at TDC"?

How did you "place the 1st plug directly over where it was pointing"? Please elaborate on what you did.

Can you show us a photo of your distributor with cap removed and the #1 cyl at TDC, on the compression stroke. Please tell us how you determined the compression stroke.

rithsleeper

I watched the exhaust valve open, then the intake valve open, then once the rocker closed I put a pencil eraser in the number 1 cylinder hole and when the piston stopped moving up that was tdc... Then I dropped the distributor in with the rotor pointing sort of toward the #1 cylinder and marked on the back of the manifold where it was pointing.Then put the cap on and aligned a prong to that marking and plugged my #1 spark plug wire to that prong. Then moving clockwise placed the other wires in order.

Let's say I somehow messed this process up (which I don't see how its possible), the plugs would still fire even if at the wrong time. The plugs are NOT FIRING at all. Its not a misfire, or a lack of a clean burn they are not sparking.

To me this seems like a wiring issue but I don't see how that is possible either. Its so simple. The way the hei units work is alternating ground and positive for firing triggers (iirc) so it could mean that trigger wire or portion of the control module is not working. In my wire diagrams though it doesn't even tell me how to test the 4 reference wires going to the distributor. Just tells me their color and they go to the ecu.

DanielRicany

You say it fires every other cylinder. How many teeth are on the reluctor wheel for the pick up coil?

rithsleeper

I will have to look but did they even make a 4 cyl version of this distributor and coil? It came as one piece with a cap and distributor. It doesn't make sense that they would put a 4 cyl distributor and a 8 cyl cap. I guess it is possible and I will check. The wiring harness is the same as a v8 truck and Camaro, it is a very common distributor setup, that would be a one in a million mistake, but I could be the millionth customer!

rithsleeper

Ok the ignition control module failed and they gave me a new one I will install when I get off work. Question now is, did I burn it out by mistake wiring something. I have power to coil (pink), the tach reference is white right next to power wire, two wires go from coil to distributor color coded red and white iirc and then the four plug to the distributor with purple black/red, think a black and a tan also. Can't really mess those up..... Just getting as much info as I can before diving in.

Driving the car at Daytona in two days.....

DanielRicany

I believe there should be a black ground wire that goes in the center between the power wire and ground wire (the one the ICM controls).

DanielRicany

Never mind... I forgot you have an external coil. Not sure how that one should work.

383vett

Are the nonfiring cylinders getting fuel?

Cliff Harris

I was thinking that...

I don't see how else you could get a spark on every other cylinder.

tunedport85inject

Do you set the commander wizzard calibration for 8 cylinders? May be you haven't set it correctly and no reference pulse from ecm to injectors ( just 4 of them)

rithsleeper

Well guys here is the solution. The module fixed the skipping every other cylinder. Half module was burnt out. However when I put the new in cyl 1 was not firing past idle. Anything above 1000 rpm cut out. I dropped my old hei and couldn't adjust timing because of clearance but it fired right up no lack of firing. I went and got another distributor from O'Riley's instead of the duralast and worked fine.

So whoever put that distributor together must have been high or something. Burnt module and bad distributor. It was a "new" unit too, not rebuilt.

Hope this post helps others in the future. Don't assume new parts work. Glad duralast wasted so much of my time. Thanks for all your input everyone.

Midnight 85

I had the exact same thing happen to mine when I switched to the small hei. I bought a Pertronix distributor, brand new and it went through 3 modules in less than a week. I ripped it out and got an AC Delco, dropped it in and it is still in there 2 years later with not so much as a hiccup. Glad you found it & all is well.

rithsleeper

Well looks like this thread is back alive. Now number one is firing for first 30 sec cold then nothing. Number 6 is sporadic so I'm thinking it might be the module.....

Might have to get a hold of an ac delco like you said. I find this very hard to believe this is coincidence that the two modules from auto zone burnt out then the distributor was bad then the one from O'Riley's went bad too. I'm pretty confident on my wiring unless there is something in the wrong place or something. I am going to try to find one of the parts places that can get a delco unit and then get a hold of a msd box I guess to make sure the spark is strong and not just fouling considering right now the tuning phase is making me run it really rich.

Even after new plug still skipped on cyl 1 though so something is wrong at the distributor end.

aklim

I'm using an MSD 8366

C409

..... Replace the ignition adapter between the 950 harness connector and the small cap HEI distributor ... they are plentiful at the pick-n-pull on GM trucks with TBI (early 90's) ... are you using an MSD ignition box (6AL) ? .......

rithsleeper

That is how I originally went to the small cap distributor. Got the small plug and rewired it into the 950 wire harness (did it right with solder and everything.). Got the wiring out of an old gm truck. ('93 iirc).

I am not using a msd box but I want to eventually but don't feel like I need to being an hei unit already.

Summit does have a free blaster coil with msd distributor right now. Might have to bite the bullet on this and get a 6a unit also.

C409

..... When you say that you rewired it I have to ask Why? ... it should just plug into the harness with a 4-wire weatherpack and into the distributor ICM ............

aklim

I think when you switch to small cap, the plugs don't fit so you have to cut and splice it into the correct harness

http://www.ebay.com/itm/Chevy-85-86-...-/301202546646

rithsleeper

You are right. The small cap distributor uses a totally different 4 prong plug. Same wires, but just different plug...