Ghettobird52

So the other day my car dies out on me mid traffic at a red light. I push my car to the side of road and start diagnosing. Instantly read fuel pressure and all is correct, check for spark and nothing. I had a problem 6months ago with spark so i had a few tools on me. I pulled the cap off dizzy and put a replacement ICM on. No spark still. I put a good Ign coil on and nothing no spark. I verify in WUD on EBL Flash that im getting DRPs. disconnect 4 wire connector of icm and still no spark. change two wire connector between icm and coil and still no spark. Check for volts at the coil and get 12 volts on pink wire in EDIT: GRAY connector, but get no volts on white wire in EDIT: GRAY connector. The white wire turns out to be the tach terminal lead.

I chase the wire out the harness and find this










I pushed a few wires around on the inside under dash and i hear my headlight motors clicking and then the interior lights go off!



I notice i have no power to my headlights, radio or interior lights. I wiggle a wire back around on the inside of the connector and power comes back on. So the c100 bulkhead connector needs to be replaced. Is it possible? How does it disconnect and removed?


I did try to bypass the bulkhead connector by splicing around it with a good wire but still was unable to get 12 volts on the tach terminal lead?



Do i have another short farther up my dash or is power getting cut somewhere to my tach terminal from this melted c100 connector.

Thanks all for information and advice

EDIT: So i got the connector apart, no terminals look fried just all this black goo every where! What is this?! i see other pics of people with the same exact stuff on it. Is this supposed to be there?

Lurbie

iTrader: (3)

Black goo is normal, that's how they kept the water on the outside and the dry on the inside.

OrangeBird

iTrader: (1)

And , putting 12 volts on the white tach wire is a great way to fry the ICM .

Ghettobird52

Excuse me i meant over 10 volts. I didnt jump any power to anything or change any wiring all i did was splice around that bulkhead to see if it would change anything.

Im just following the diagnostics from the service manual (see attached doc)

STEP 4: Both terminals (+, C) show 10volts or more on 2 wire connector with ignition on. Reconnect dist 2 term conn

With Ign "ON" check voltage from tach. term to gnd

3 options ; Over 10 volts, under 1 volt, 1-10 volts. Im getting under 1 volt.

EDIT: Sorry in my original post i meant the GRAY connector on the coil, not the black. SORRY!

Ghettobird52

So i put everything back together and now im reading intermittently voltage on the tach terminal? I'll see 2.6v then it'll drop to 200 mV then stay there and then i'll see .7v n itll drop back to mV....

Ghettobird52

I wanted to update this thread. so after completely ripping my interior apart and finding zero breaks in my tach wire i was stumped. I finally realize that you are supposed to test the tach lead WITH the wiring harness plugged into the coil!!!. I checked at the connector behind the coil with everything plugged up and boom 12.10v

So i jump back to my GM service manual and find that icm is usually the cause. I had an old one that was known good but it was sitting in my garage for 4 years and it wasnt working. So I give a new one a shot from the parts store. BOOM i get spark.

Heres the problem i pulled my dizzy and swapped it in and out with my old dizzy about 5 times just going in circles. Well i was being lazy and not being 100% with the marking of the rotor location. I thought i was close enough to when i would get spark it would run and i could adjust from there.

I was wrong! The car will have VERY HARD starts but instantly die out and back fire smoke! So now i got spark back and fuel is there but my timing must be completely off!

What is the easiest way to find TDC on #1? Heck easiest way to time this beast!

Thanks all

Tuned Performance

iTrader: (92)

Sounds too advanced if it’s cranking over hard.
To find tdc disconnect power from your distributor. To avoid getting zapped.take out the number one plug and put your finger over the plug hole. Have someone bump the starter until you feel compression. Look at the timing market and rotate the engine market to tdc.
On the distributor body you can put the cap on and make a mark on where the number 1 cylinder wire will be. That way you know about where the rotor needs to face.
Hope the gibberish makes sense

Ghettobird52

Tuned Performance

iTrader: (92)

You got it .

Ghettobird52

Ok so i had someone bump the starter while i felt for compression on #1 with the spark plug out. Felt it, stopped there. Pulled off the cap of my dizzy and noticed the rotor was facing 180* backwards. Rerouted the wires to match the location of the rotor, and attempted to start it. Only got to try to start it once as my battery died out after but it still didnt start. It had a small backfire still but nothing like before.



One thing i did notice is that my #1 plug is carbon fouled to hell. Most likely because my idiot self didnt un plug the fuel pump/injectors while trying to get my spark back. So im pretty sure all the plugs are gone like this. I wonder if i need new spark plugs or would it still start with plugs this fried? The threads were crazy dirty, 'smudgey' as well but i wiped them before the pic.

Thanks again

Tuned Performance

iTrader: (92)

looks like your running pretty pig rich.
New plugs with a larger center electrode might be a better way to go.

Ghettobird52

Yeah just bought new plugs going to change them out. Would fuel fowled plugs cause no start issue? backfiring?

EDIT: Also with the method of finding TDC i used how would one know your on the compression stroke and not the exhaust stroke?

Richardman1992

Ghettobird52

Yeah but wouldnt you feel air pressure on both compression/exhaust strokes?

Richardman1992

Tuned Performance

iTrader: (92)

I think the timing issue is the cause of the no start. It could be flooded I’m just not sure what variables your dealing with . I see you have the ebl. Is this first fire up since it’s install or have you been fighting a spark issue ?

Ghettobird52

first attempt at start since the new ICM? Yes first start. No spark issue before car broke down. It was starting up and running daily for months.

Im changing plugs now. They are all fouled up and reek like fuel.

Tuned Performance

iTrader: (92)

Good hot spark with a spark tester ?
I use one from acdelco that’s set to 40kv
Any changes made to the ebl cold start enrichment?

Ghettobird52

I dont have a spark tester checking for spark with timing light, which i guess is prob not the best tool. No changes to tuning

I went to check for spark today to verify with timing light and had a 2nd hand turn the motor over. As soon as we turned it over for a few seconds and stopped it made a large gunshot blast out of the muffler? I had fuel pump disconnected at the connector above rear end so there was no fuel supply from the injectors?!

I guess there could of been fuel from the day before still in the cylinders. idk im freaking out now lol

Ghettobird52

I wanted to update this. After a few weeks of being out of town i finally got back on the f-body this weekend. Ok so i replaced all spark plugs, found TDC by bump start/finger method. Noticed i was actually 45* advanced off tdc. Adjusted, and started the car up! Ran but slow, pulled the timing light out and adjusted to *2BTDC. Im back on the road again

Thanks everyone for your input and advice