1991 Q with possible timing chain jump

[mattd1979]

A friend of the family that now owns my mom's 91 Q45 went to pick the car up from a tire shop after getting two tires mounted. It started and shut back off. When he went to start it again, it sounded as if all of the spark plugs were removed when it turned over with no sound of compression. The timing guides had been replaced when the owners before my mom had the car. According to the receipts, an entire kit was used. Replacing the chain along with the guides. Is there a possibility that the engine jumped time in such away to allow for all 8 cylinders to be without compression and not interfere with the valves? I know the engine is an interference design but just wondered. He said that he didn't here any clanking when the engine shut off. It was like he turned the key off he says. I had him watch the clutch fan as he tried starting the car to see if it was turning and he said it was.

So again, does anybody know if it is possible for the engine to jump time enough to cause compression loss and still not interfere with the valves?

Matt

[OwnerCS]

Matt - Some members here have had that happen with some serious engine damage. Anything is possible though somewhat unlikely. I would try to get someone who is somewhat familiar with the engine to listen to it. As a place to start, some plugs on the driver side bank can be pulled for a quick compression check. Could it be something with no fuel pressure (e.g. pump and/or fuel pump control unit) that is preventing any firing?

Here's a picture of the timing mark (gold and sliver link) line up below if someone decides to go in deep.

[mattd1979]

The problem was one that I had a feeling was the cause. What happened is the rings to the pistons lost their seal after a couple of brief start and stops. I had to cut fuel to the injectors and spin the engine over with throttle at wide open position until the compression built back up and it fired over. No jumped timing. I had forgotten how easy it is for this to happen. It had happened to me before to. When the engine is started and you go to move it over to get out of someones way in the driveway for example, it's a good idea to let it idle for about 30 seconds before shutting it back off or else this can happen. I have been doing this with my car since I got it out of habit but forgot why. Now I remember. Oh, I checked the compression before and after and before it was at 62 psi. After it was up to around 130 psi I believe.

Matt

[Q451990]

Glad to hear it wasn't something more serious!

Heath

[mattd1979]

You aren't kidding. It certainly took a load off my mind for two reasons. It meant I didn't have to tear into his car and I didn't have to be as concerned about mine.

[2brokey]

thank goodness you don't have my luck :P I think my 91's chain really jumped...for real...