I am working on a friends 1989 Formula. Why does it die everytime I unplug the EST Bypass (brown wire) on the firewall?

The base timing (with the wire connected) is staying within a few degrees of 5 BTDC. But as soon as the connector is unplugged, it dies. It will not start with this unplugged. ANy help will be greatly appreciated.........

Kev

 

Base timing is retarded too much.

 

Thats what I thought too. So I turned it up where it will crank over and try to start but the engine immediately dies EVERYTIME... I checked the timing with my friend cranking it over to get it close (I know...) and then plugged the connector back up. It will run, but it will not rev up. It just spits and sputters..... The timing will then read better than 20 degrees BTDC at idle....

We have unplugged the MSD BTM, tried colder plugs, went back to stock plugs, new wires, bypassed the supercharger. His laptop died, so scanning it is alittle hard right now. I am almost tapped out of ideas. It will not pull above 3000rpm now.

I feared an internal engine problem, but that doesnt wxplained the strange timing issue. This has been a gradual problem....

Also, the tach in the dash will actually drop when he tries to rev it up until he lets off of it, then it will rev up for a split second as the throttle is released...

 

Any thoughts?

 

What happens when you go into field service mode?

 

Well, I unplugged the TPS to go into Limp Home mode. The timing is steady at 22 BTDC. If the timing is turned down below about 15, it dies. It still refuses to rev up. It will drop in revs until the throttle is let off, then it will rev up as the throttle is released.

This started as a small miss after he ran it on the dyno at The Fbody Gathering last month. Now it has progressed into not being able to rev or even pull out of his driveway.

He has a new MSD BTM, coil, wires, plugs, control module and pick up coil. We tried my BTM and coil, but there was no change.

I'll do a compression check (if he ever gets out of bed today0 Will a dead cylinder or two cause the engine to not rev? He is running 11psi on cast pistons ......

I'm stumped about the timing issue though. I set the timing on it when he put on all of the ignition parts. No problems. Not a month later, the timing is high and it will not set any lower and stay running. How did it move? Who knows.

Later.: