Engine died while cruising

[AlphaAssault]

I cant figure this out, and it is beginning to frustrate me. I was cruising down the road, engine at a constant ~3200 rpms @ about 70mph, and suddenly the engine just stopped. The RPM gauge dropped to zero (even though i was still in gear, this might be important); but all the dash lights and everything remained on. It was almost as if I had turned off the engine with the key, except I didnt. I coasted it to a stop, and tried to restart the engine, and it cranked but would not start up again. Here is what I have checked:

-No smoke when the engine died.
-No shaking or stuttering before the engine died.
-No sound (no pop, ticking, or knocking) before or when the engine died.
-ECU is ok.
-Plugs look fine (i.e. not burnt or crushed).
-Fuel pump is working.
-The previous owner put the cam pulleys on wrong, so the timing marks both point up instead of together. Its always been like that, so I cant tell exactly if the belt slipped a tooth. The belt does turn, however, and there is no knocking or ticking coming from the engine when I crank it.
-Battery terminals are tight, as are the grounds to the firewall.
-All fuses in the engine bay are good.
-Oil looks fine.
-I didnt have time to check for spark. Im thinking this might be the problem.
-Cam angle sensor is tight, but I dont know how to test it any further.

Next time I go out there, what else should I look at in addition to checking for spark?

 

[pj91gsx]

I would check for spark 1st! You assumption about the timing being set wrong is not right. It couldnt be that far off and still run. If it did run, it wouldnt run for long. I had one, that ran with the timing off, i drove it down the road, then cut it off. It never would crank up again. I reset the timing and it was ran again.

 

[steve]

How do you know the ECU is good? Do you get a check engine light for 5 seconds right after turning the ignition on? The ECU controls the spark and fuel to the engine. Without it nothing interesting happens.

Does your fuel pump turn on when you engage the starter?

The tach is electrical and is based off the coils being pulsed by the power transistor.

The CAS provides the ECU with it's engine timing information. Of the 4 wires running to the CAS, two are signal lines that are pulled up by the ECU to 5v when it's on. The other 2 are the MPI power and ground. As the CAS is turned the signal wires will be pulled down to ground to signal to the ECU. One does it twice per CAS rev the other 4 times. If you not seeing 12v on the CAS power wire then you need to check at the relay and fuse.

The 90 harness:

pin 1 (Larger)Black Ground
pin 2 Red +12v Power
pin 3 White TDC (to ECU pin 22)
pin 4 Black Crank Angle (to ECU pin 21)

 

[Below Ambient]

that happened to me several times until i grabbed a retainer clip for the CAS sensor. It was actually pretty embarrassing because i had the car towed to my house and called my local DSM wise-man to come fix it 30 miles away... it took him 10 seconds

 

[AlphaAssault]

How do you know the ECU is good? Do you get a check engine light for 5 seconds right after turning the ignition on? The ECU controls the spark and fuel to the engine. Without it nothing interesting happens.

Does your fuel pump turn on when you engage the starter?

The tach is electrical and is based off the coils being pulsed by the power transistor.

The CAS provides the ECU with it's engine timing information. Of the 4 wires running to the CAS, two are signal lines that are pulled up by the ECU to 5v when it's on. The other 2 are the MPI power and ground. As the CAS is turned the signal wires will be pulled down to ground to signal to the ECU. One does it twice per CAS rev the other 4 times. If you not seeing 12v on the CAS power wire then you need to check at the relay and fuse.

The 90 harness:

pin 1 (Larger)Black Ground
pin 2 Red +12v Power
pin 3 White TDC (to ECU pin 22)
pin 4 Black Crank Angle (to ECU pin 21)

I can tell the ECU is okay because the CEL comes on and the boost needle goes to zero when I turn the ignition on, and the computer clicks once when I turn the ignition off.

The fuel pump is working because the plugs were wet with fuel after cranking the engine trying to get it to start. And I can hear it while cranking the engine.

Where is the cas fuse and relay?

 

[steve]

Where is the cas fuse and relay?

MPI fuse and MPI relay. Since your ECU turns on they are fine.

If the plugs are wet check the ECT sensor and wiring.

 

[AlphaAssault]

MPI fuse and MPI relay. Since your ECU turns on they are fine.

So does that rule out the cas, or should i still inspect it and its wiring thoroughly?

 

[steve]

No it does not rule out the CAS, just the the MPI power circuit works.
It doesn't rule out the ECU either just lowers the chance of it being the cause. 90+% of the time the ECUs are non-functional which is why you check for the CEL first. The odds are now higher that something other than the ECU is the cause.

I don't know how the OP could have put the cam sprockets wrong short of pulling out the dowel pins but you should check the compression when you check for spark and fix that when you can. Without the dowel pins there isn't anything insuring that the alignment of the sprockets and cams remain indexed.

 

[AlphaAssault]

No it does not rule out the CAS, just the the MPI power circuit works.
It doesn't rule out the ECU either just lowers the chance of it being the cause. 90+% of the time the ECUs are non-functional which is why you check for the CEL first. The odds are now higher that something other than the ECU is the cause.

I don't know how the OP could have put the cam sprockets wrong short of pulling out the dowel pins but you should check the compression when you check for spark and fix that when you can. Without the dowel pins there isn't anything insuring that the alignment of the sprockets and cams remain indexed.

My cam gears look like this. http://www.dsmtuners.com/forums/mai...ng-marks-way-off-cam-gears.html#post152329352 Apparently thats normal? I did not know that.

EDIT: what does the CAS actually control? I read that it controls the timing for both fuel and spark. Someone else on here ruled out the CAS because they had fuel and no spark.

 

[steve]

Not that not normal. What's correct is what's shown on the 1G timing belt VFAQ Timing Belt VFAQ (Timing Belt TSB - ENHANCED)

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[AlphaAssault]

Illl make sure to take a closer look at the timing marks when I check everything else. Still, as far back as i can remember, the timing marks have always pointed up on the sprockets, and its driven fine thus far.

 

[projekt1]

I cant figure this out, and it is beginning to frustrate me. I was cruising down the road, engine at a constant ~3200 rpms @ about 70mph, and suddenly the engine just stopped. The RPM gauge dropped to zero (even though i was still in gear, this might be important); but all the dash lights and everything remained on. It was almost as if I had turned off the engine with the key, except I didnt. I coasted it to a stop, and tried to restart the engine, and it cranked but would not start up again. Here is what I have checked:

-No smoke when the engine died.
-No shaking or stuttering before the engine died.
-No sound (no pop, ticking, or knocking) before or when the engine died.
-ECU is ok.
-Plugs look fine (i.e. not burnt or crushed).
-Fuel pump is working.
-The previous owner put the cam pulleys on wrong, so the timing marks both point up instead of together. Its always been like that, so I cant tell exactly if the belt slipped a tooth. The belt does turn, however, and there is no knocking or ticking coming from the engine when I crank it.
-Battery terminals are tight, as are the grounds to the firewall.
-All fuses in the engine bay are good.
-Oil looks fine.
-I didnt have time to check for spark. Im thinking this might be the problem.
-Cam angle sensor is tight, but I dont know how to test it any further.

Next time I go out there, what else should I look at in addition to checking for spark?

Same thing happened to my other 1g. I haven't taking the longblock apart but it isn't good on the head alone. When I removed the valve cover I immediately noticed that most the rockers on the intake side had fallen off. The intake cam was scarred in a few spots as well.

Like the OP said, I too had no symptoms of anything, was cruising in fight just normally when all of a sudden she shut down..



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