Getting spark when key is released

Hi all,

I am trying to finish up wiring up my 2.9 L out of a '88 going into a '84 BII.
I don't get spark when turning over the engine. But, when I release the key I'll get an intermitent spark.
On certain rotations or attempts I'll get one cylinder ignition even. What is happening here? I have tested coil, module, wiring in run and in start position. Everything is showing power with my test light.
Can bad grounding cause this to happen?
Any and all help is appreciated.

Hawkeye

Hawkeye58 said:

Hi all,

I am trying to finish up wiring up my 2.9 L out of a '88 going into a '84 BII.
I don't get spark when turning over the engine. But, when I release the key I'll get an intermitent spark.
On certain rotations or attempts I'll get one cylinder ignition even. What is happening here? I have tested coil, module, wiring in run and in start position. Everything is showing power with my test light.
Can bad grounding cause this to happen?
Any and all help is appreciated.

Hawkeye

Click to expand...

yes... poor grounds can cause a multitude of issues. recheck 1st

2nd would double check to see if the wiring is correct for the firing order.

3rd you may/should have to get a EMC (engine computer), from an 88' or better. The 88' EMC isn't looking for the EGR and few other items related to the emissions...Presuming that you've used the 84' EMC, this can have some possible "runnability" trouble.

Also possible that the ignition switch on the steering colume is lessthan correct.

IMenriched said:

yes... poor grounds can cause a multitude of issues. recheck 1st

2nd would double check to see if the wiring is correct for the firing order.

3rd you may/should have to get a EMC (engine computer), from an 88' or better. The 88' EMC isn't looking for the EGR and few other items related to the emissions...Presuming that you've used the 84' EMC, this can have some possible "runnability" trouble.

Also possible that the ignition switch on the steering colume is lessthan correct.

Click to expand...

The firing order wiring is all labeled and double checked.
When I got the engine I pulled the complete harness and the brain with it.
Now the ignition switch is from the '84. Not sure about it.

Hawkeye

Is sounds like the coil primary is getting a constant current when the ignition switch is on, and while cranking. By turning the ignition switch off, this is
removing the 12V, creating the di/dt that the coil requires to generate a spark.

I believe what Mr Ayers is trying to say is, the coil isn't getting the trigger signal.....


If that is the case, you wired the system wrong, the pickup coil is bad, or the module is bad.

almostclueless said:

I believe what Mr Ayers is trying to say is, the coil isn't getting the trigger signal.....


If that is the case, you wired the system wrong, the pickup coil is bad, or the module is bad.

Click to expand...

Right now I'm inclined to think the wiring is messed up somewhere. The Distributor is new only about a week old, and the module tested good on the day I got that distributor.

Hawkeye

Is it duraspark on a 2.9?


What dizzy did you use?

almostclueless said:

Is it duraspark on a 2.9?


What dizzy did you use?

Click to expand...

It's stock with a TFI ( Thick Film Ignition)
Stock Dist.

Hawkeye

Got it

Good news folks! I retraced all my grounds for pins 20, 40, and 60. Also pin 49 (Hego ground). The fuel pump ground. Then the body, engine and frame grounds. I found two that I don't like, the braided ones running from engine to body and the other to the frame. Quick threw together one of each from some battery cable I have laying around and BINGO!! I have spark, and I mean serious spark. It's operating in the correct fashion as well not when the key is being turned off. Also picked up more speed in my starters crank speed as well.
I want to thank all of you that have chimed in on this. You all got me thinking and helped me work it out.
Man... am I relieved.

Hawkeye

Update

Hi all,

Well it's been a long while since I posted about my BII.
Here is a update.
Once I had the engine running for a few sessions I went forth with my first mod.
I installed a Taurus two speed electric fan and also the 130 amp Alternator from it as well in order to handle the load. That set up is doing very well.
Then a day later the engine started to blow blueish smoke out the exhaust. What a bummer. So... I decided to pull the engine after checking everything I could.
Once I got it on the stand and torn down I found what it was. I had done a re-ring job on it prior to my installing it and the other troubles. When I installed the rings I had gotten the gaps lined up on the #5 piston.
I decided at that time since it was all apart again that I'd take it and do a complete build. Now several months later I am now re-constructing it.
It's bored 30 over and balanced with a 4.0 L flywheel and clutch going into it this time. I also aquired some newer heads from a '89 (with the stronger pedestals to prevent cracking) those are fully rebuilt as well. Also a newer 5 speed trans. will replace the original 4 speed.
The good thing now in addition to the fact that I have a brand new engine going in, is that all the electrical for ignition is solved and doing well. Once I have the engine in and running I get to proceed to the dash wiring harness. Hopefully tath will sort it's self out relatively easy.

Well that's it for now. More later.

Hawkeye

when you say you retraced the grounds to the pins are you talking about the pins on the computer in the cab? i might have some ground issues and might want to try this, if you have some time, could you explain?
thanks
kyle

Hawkeye58 said:

Good news folks! I retraced all my grounds for pins 20, 40, and 60. Also pin 49 (Hego ground). The fuel pump ground. Then the body, engine and frame grounds. I found two that I don't like, the braided ones running from engine to body and the other to the frame. Quick threw together one of each from some battery cable I have laying around and BINGO!! I have spark, and I mean serious spark. It's operating in the correct fashion as well not when the key is being turned off. Also picked up more speed in my starters crank speed as well.
I want to thank all of you that have chimed in on this. You all got me thinking and helped me work it out.
Man... am I relieved.

Hawkeye

Click to expand...

my '84 mustang has the exact same problem with only getting spark when I let go of the key. I worked on mine for about 2 weeks and found a few wiring trouble spots but still don't have it fully solved. I will check all my grounds now though, i hope that fixes my trouble as well. mine also smoked some at idle but i found out that the crappy Holley on it was the trouble, so i slapped a good ol autolite 4100 on it, now there is no smoke and it never ran so good in the 8ish years i've owned it.

Grounds

The pins i refer to 20, 40, and 60, all are black wires going to those numbered pins on the computer.
One leads to the kick panel passenger side right next to the computer. One leads as I recall to a junction with several more grounds in the harness in the engine bay, one of those wires goes to ground at the battery. Then the other if I remember right goes to the engine. Then there are the others: engine to frame, body to engine. I hope that helps. My biggest trouble spot as it turned out was the braided one from back of engine to the firewall, ( a small post next to the wiper motor ) It started to emit smoke when holding my key on for a long time. That tipped me off to it. The braid looked good too, so looks can fool you. I eliminated it and used a battery ground cable I had in good condition to take it's place.

Hawkeye

Key on problem

If you find that the grounds are okay and you still get the spark at the time you release you key, it can be the ignition switch that has worn out. I almost replaced mine, and would have if the grounds hadn't proven to be the issue.
I have since learned that the switch has a reputation of failing and giving the issues of the spark happening at the turn off of the key.
Hope that helps some, good luck you guys.

Hawkeye

Another update

Here's what I've been doing to the engine recently.
the build:

Ring installation

IMG]http://i684.photobucket.com/albums/vv202/Hawkeye1958/Bronco%20II/Engine%20build/DSC00422.jpg[/IMG]

Fresh coat of paint

IMG]http://i684.photobucket.com/albums/vv202/Hawkeye1958/Bronco%20II/Engine%20build/DSC00422.jpg[/IMG]





Then the Install:











The engine is in now with a 5 speed OD and a flywheel and clutch for a 4.0L a few more days and I'll have it running I hope.

Hawkeye