no start problem
Thread Starter
Burning Brakes
Joined: Jul 2000
Posts: 1,045
Likes: 3
no start problem
I have a C3 with a speed density TPI engine. I am running a 7730 ecm with a howell engineering harness.
Car was running great this weekend. Got home and had the car running in the driveway for a while. The car started to stuble and die. Got the car running and car died a second time. Cranked and got car running but after a backfire. Died third time and will only crank.
Fuel pressure is 49lbs and hold for quite a while. Cranks and shows spark through timing light. Replace ignition module , tried a new memcal, prom,ecm. Show 12 volts at all eight injectors. Car will not fire or show any sign with starting fluid. Check that timing is on by checking rotor location and timing pointed is ok indicating no timing jump.
Any ideas....
Car was running great this weekend. Got home and had the car running in the driveway for a while. The car started to stuble and die. Got the car running and car died a second time. Cranked and got car running but after a backfire. Died third time and will only crank.
Fuel pressure is 49lbs and hold for quite a while. Cranks and shows spark through timing light. Replace ignition module , tried a new memcal, prom,ecm. Show 12 volts at all eight injectors. Car will not fire or show any sign with starting fluid. Check that timing is on by checking rotor location and timing pointed is ok indicating no timing jump.
Any ideas....
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
During cranking, use your timing light to determine if spark timing is correct. The injectors are connected to 12v and the ECM pulses each second injector coil wire to ground, so 12v on all injectors doesn't tell much. Use a noid light (parts house), or make one with an LED and a series 680 ohm 1/4W or higher resistor across injector plug to see if it pulses during cranking. If you make one, polarity across injector plug must be correct. Bring a grounded wire close to a plug wire during cranking, spark should be at least 1/2 inch and snappy. If you have spark and at the right time, fuel pressure, injector pulses, then do a compression test. Backfire tells me the spark timing is not correct.
Thread Starter
Burning Brakes
Joined: Jul 2000
Posts: 1,045
Likes: 3
Got the car running tonight. Car not firing with starting fluid was biggest hint. Double checked spark at the plug. All I was able to do was get a small white spark at the plug. I installed a ignition module and everything in the distrubtor is looking good. So I decided to replace the MDS coil that I installed this spring. Installed the stock coil and the car fired right up.
Thanks for the help guys.
Thanks for the help guys.
