I got my car tuned last weekend(Defined Autoworks did a fantastic job) but I screwed something up the other night. I had forgotten to tie down my battery when I put it back in the other day and for some reason didn't solder my battery ground fitting(just crimped it) when I installed a few years ago. When I shifted into 2nd after a hard 1st gear pull, the main battery ground pulled itself out of the fitting. There was still a small ground connected to my battery that went directly to the Microtech. The car managed to say running, but the electrical system was going crazy. I found and fixed the problem the next day and everything electrical seems to work fine.

However, it is very difficult to start now(checked the compession, still fine on all rotors), and when I do get it to start it sputters and backfires. It also builds boost just by revving, and the manifold glows orange after a couple of revs. It seems as if the timing is now retarded quite a bit, but I swapped in a spare ECU and it did the same thing, so I know the Microtech isn't fried. Is it possible that the CAS was damaged?

I also put new plugs in it, but I havn't been able to check the timing yet. Any info on possible causes would be helpful, as I'm trying to figure out what is wrong before I go home and work on it this weekend.

 

Well, I tried swapping out crank angle sensors, didn't help. Swapped in a different primary coil, and it definatly seemed to help a bit. I will start it up one second, and it will rev, and 2 min later I try to start it and its back to popping and major hesitation.

Anyone have any ideas on what it could be?

 

I will paypal $10 to the first person who correctly identifies the problem, $20 if you can help me figure it out before saturday(tommarow) night.


When I do get it started and it revs freely, it seems to "load up" after about 30 sec and starts hesitating badly and backfiring, almost like the timing is changing.

 

take some jumper cables and use them to make a ground between the - terminal and the intake manifold and the block. the small ground on the motor might be toasted?

 

Check to see if you have a vacuum leak.

 

Are you using a microtech external ignitor (x4 or x6) or the factory ignitor/ignitors? If so, I'd say you could have damaged one. They die very quickly when run with a bad earth or no earth.

 

I have a large 6 gage(I think, its about 1/4" thick) ground going from the engine to the firewall replacing the small factory ground. I'll try running a new ground anyways though and see if it helps.


I'm running a MAP sensor, and the signal line is in great condition and hooked to the plenum. Vaccum leaks in other places shouldnt make a difference.


I'm running the factory coils right now, and I replaced the primary coil with a spare one, but its doing the same thing as before now. I'll double check the wiring going to it.

 

Are there any connections which could have been pulled when the battery and associated area moved around? Often when I see these problems they are caused by a poor connection. Maybe a marginal solder joint broke free?