car suddenly wont start - never ran great anyway, esp. cold, now cranks, but won't st

rjSupra · 03-31-2011, 12:50 AM

Ok, so I hooked up the timing gun right this time.
The timing (w/ TE1 and e1 jumped) was reading 15 degrees. I dialed it back lower and it almost immediately bogged down and sounded like crap near 10 (the idle speed dropped significantly and was barely chugging).

I bumped it up to 18 degrees BTDC and it sounded way better. But my idle jumped up from 600-650 rpm to about 1000 rpm... hmmm....

So I turned car off to see if car would re-set the idle itself and it did (at 18 now). So then I decided to try to dial it slowly about the 11 degree mark (and see if the idle would re-program itself) which it did and I have the idle stabilized at 600 - 640 RPM.

I also clamped the pickup on #1, #3, and #5 spark leads. I was trying to use this as a quick test to see if I was even getting any electric up from each ignition coil, and I was getting the light coming on all three. So I am sort of guessing that I probably don't have a toasted ignition coil, or a bad igniter. The plug wires all look pretty solid, they are Sumitomo from 2002. But keep in mind this car was without inspection sticker since 2005, so it was almost rarely driven for many years down a private road only with little mileage on the wires.

When I throttled the gas, I was getting, uh, not full on exhaust backfires, but a deeper and quieter popping after abruptly letting off the throttle from 1000 to 2000 rpms (it was not a loud tail pop / snap, sounded more mellow and deeper up the exhaust sort of). This happened before and after I set the ignition to 15 (at start), 18 or so as where to my ear the car seemed to run smoothest, and then to 11 where I settled on setting the ignition.

My friend was saying that on his old Buick ('67 Skylark), he advanced his spark to 18-20 degrees to make it run smooth - or it ran quite poorly where it was specified to run. He later discovered a significant vacuum leak many months or years even later, and then could set it back to spec. He was suggesting I could have a vacuum leak perhaps. Anyone think that is the case here?

Thanks!

03-31-2011, 12:50 AM	#22
rjSupra 3" Exhaust Join Date: Sep 2010 Location: NH Posts: 86	re-set ignition timing - details Ok, so I hooked up the timing gun right this time. The timing (w/ TE1 and e1 jumped) was reading 15 degrees. I dialed it back lower and it almost immediately bogged down and sounded like crap near 10 (the idle speed dropped significantly and was barely chugging). I bumped it up to 18 degrees BTDC and it sounded way better. But my idle jumped up from 600-650 rpm to about 1000 rpm... hmmm.... So I turned car off to see if car would re-set the idle itself and it did (at 18 now). So then I decided to try to dial it slowly about the 11 degree mark (and see if the idle would re-program itself) which it did and I have the idle stabilized at 600 - 640 RPM. I also clamped the pickup on #1, #3, and #5 spark leads. I was trying to use this as a quick test to see if I was even getting any electric up from each ignition coil, and I was getting the light coming on all three. So I am sort of guessing that I probably don't have a toasted ignition coil, or a bad igniter. The plug wires all look pretty solid, they are Sumitomo from 2002. But keep in mind this car was without inspection sticker since 2005, so it was almost rarely driven for many years down a private road only with little mileage on the wires. When I throttled the gas, I was getting, uh, not full on exhaust backfires, but a deeper and quieter popping after abruptly letting off the throttle from 1000 to 2000 rpms (it was not a loud tail pop / snap, sounded more mellow and deeper up the exhaust sort of). This happened before and after I set the ignition to 15 (at start), 18 or so as where to my ear the car seemed to run smoothest, and then to 11 where I settled on setting the ignition. My friend was saying that on his old Buick ('67 Skylark), he advanced his spark to 18-20 degrees to make it run smooth - or it ran quite poorly where it was specified to run. He later discovered a significant vacuum leak many months or years even later, and then could set it back to spec. He was suggesting I could have a vacuum leak perhaps. Anyone think that is the case here? Thanks! __________________ 88 Supra 7M-GTE Turbo, TEMS, Targa stock