Got spark, got fuel, no start.

[CheckerSHO]

I just aquired a 1990 SHO that has an odd problem. I've seen the car run before...it ran good about a month ago. Then one day it just shut off..and the tach dropped. Some dissecting found a bad crank sensor. The guy replaced that and put it back together....now it wont start. its got spark and fuel. Wires are on right. It will kinda start to hit at first but dosnt ever run. I tried holding the gas pedal down some and cranking it and it backfired thru the intake. Thats all i know right now...havnt had a lot of time to work on it yet. Sound like it might of jumped time maybe? Just looking for some opinions.

Thanks
Ely

 

[fredhurderjr]

Check to make sure you've got the 3rd component - air. Air in, and air out. I had a clogged Y-pipe that kept a perfectly good motor from running in my 91.

If you have spark, fuel & air, it's timing of some nature.

Good luck!

 

[ISHOU]

First of all,welcome to forum. There are some very knowledgeable people here.Make sure the CPS was gapped at .030. Sure sounds like a timing issue if the engine backfires and you have confirmed fuel.

<small>[ July 11, 2002, 11:27 PM: Message edited by: ISHOU ]</small>

 

[CheckerSHO]

ISHOU:
First of all,welcome to forum. There are some very knowledgeable people here.Make sure the CPS was gapped at .030. Sure sounds like a timing issue if the engine backfires and you have confirmed fuel.

Thanks He did gap the CPS to .030 he said. He also said he did the cam sensor without removing the timing belt so unless it jumped time at the same time the cps broke i duno how it could of done that...but its going to be the first thing i check besides obvious stuff i guess.

 

[Chrisssssssss]

Where did you check the fuel? Does it keep pressure? If the pressure drops, then maybe check your Fuel pressure regulator. Does the car just die, or does it idle a bit before it dies?

 

[pjtoledo]

Slap a timing light on it to see if the spark is at the correct time. A backfire through the intake could possibly be a bad intake valve. A compression test may confirm that. First I would check the timing belt, two cam dots straight up, crank dot at about 5 o'clock aligning with a mark in the casting.

Perry Toledo,Ohio

 

[CheckerSHO]

Update--i pulled off the upper timing belt cover for a peek and first i noticed a chunk out of the side of the belt. Then i went to see if the marks lined up and well the cams are still synched but i think it jumped time. The paint marks are gone off my crank pully but theres a notch i can feel with my finger that when i put it at 0degrees, the cam marks arnt to the top yet.
So im pretty sure this is the problem...my next question--is the SHO engine an interference engine? I've heard its not.....
It still attempts to start so some combustion is still taking place....whats yalls opinion...think the valves are bent?

edit-The cam marks arnt quite to the top, but not enough off to be 180 off. they are like 4 or 5 teeth from the top.

<small>[ July 13, 2002, 01:16 AM: Message edited by: CheckerSHO ]</small>

 

[sdpatt]

There are two notches on the crankshaft damper. When rotating clockwise, the first yellow notch is at 60 degrees BTDC. The second, white mark is at 0 degrees BTDC. If you align the second (white) mark on the damper to the 0 degree mark on the timing belt cover, the camshaft index marks should align with the marks on the rear timing belt cover at 12 o'clock. even if the timing belt were off, you would get some combustion. Probably noisy combustion and backfiring, but some ignition.

 

[CheckerSHO]

Ok did a timing belt and water pump today...just got it back together. started raining right before i got it all together so underhood got pretty wet while i still worked on it. Fired it up and it runs now but runs pretty bad. seems to be missing a cylinder . If it stops raining ill try to drive it and see if it levels out...
could enough carbon have built up to bend some valves?