J30 Won't start

[wirelessnut]

1996 J30 starter turns, but the engine will not start. It doesn't even "fire" while the starter is turning over. The starter just turns over at normal speed and you can tell the engine is rotating by the sound of the starter, I mean the starter isn't just spinning - it is rotating the engine.

I pulled the fuel line just above what I think is the fuel filter, on the passenger side engine compartment and checked for pressure. When the ignition switch is turned to ACC only, there is no pressure. Turn the key just past ACC on the way to crank, but not quite to where the starter begins to turn over then the fuel line is getting pressurized and I can hear the fairly quiet humming of the fuel pump when the key is in that position. So by both those tests I'm pretty sure I've got fuel.

I've tried floorboarding the gas pedal while cranking, for 10 seconds at a time. Still no joy.

The timing belt was replaced maybe 15K ago, and the engine was running beautifully. It just died in a parking lot the other day and wouldn't start. The MAF sensor was replaced at the same time as the Timing belt.

The engine isn't throwing any codes, except an initial EGR Valve code which I cleared and that hasn't come back since the engine won't start.

TPS sensor appears to be working.

I'm not sure how to check for spark in this car, but I'm going to try it the old fashioned way, by pulling or substituting a spark plug in a wire, and grounding out the threads and watch for spark.

I am getting good strong spark.

Anybody have any ideas or suggestions for a troubleshooting checklist? Where do I go from here?
Modified by wirelessnut at 3:16 PM 5/11/2009

[driverdriver]

This is a toughie.

I don't know what to suggest. From what you've written you've been pretty systematic in trying to diagnose the problem.

I'm assuming the timing belt is still intact.

[wirelessnut]

I haven't pulled the covers because I think the timing belt has to be intact, since I'm getting compression in all cyls.

I have wondered if the timing belt slipped, maybe on one side? I wondered that because compression is way low on the drivers side. Can anybody confirm that really might be a cause of the compression or starting problem, or rule that out for me? I don't really know, I'm just guessing and I'm looking for somebody with experience that could say yes or no.

More information: All the NGK sparks but one were normal except the middle cyl on the drivers side, it had a lot of oil. The oil was above the threads, even on the bolt and ceramic.

Here's the compression results.Passenger front to rear - 120, 140, 135 all normal looking sparksDrivers side front to rear - 100, 90, 90 middle spark bloody with oil all the way up to the ceramic.

So it's abnormally low on the drivers side, and maybe I have a gasket leak of some kind? Valve cover is what I'm thinking, maybe even head gasket?

In case it might be injector pulse failure (I don't have a noid light, wishing I could find one for J30 if anyone knows where I can order one please post) I sprayed some Carb Cleaner into the air intake while cranking (past the open butterfly valves, in both sides), but there was no sign of combustion at all. Nothing. I know each and every spark is firing because I've pulled them all plugged them in and watched them spark while the engine is turning over.

If it's injector pulse failure, fuel might not be getting there.

Somebody with experience, give me an opinion here - It seems to me that even if you pulled half the spark plugs on a good engine, you should get some combustion? It seems it would run like hell shaking mightily if it does start, but it should at least cough once or twice while turning over!

This is a complete combustion no show. Even if there isn't enough compression in half the cyls to kick the other half should kick at least once in a while.

I know the spark isn't being killed.Is there a kill switch in this car for the injector pulse?

How do you fix injector pulse issues anyway?

I'm grasping at straws and may have to turn this one over to a pro. At this point, they are likely to tell me I need an engine overhaul, and after I fork up enough money for that they'll stumble on the solution somewhere along the line for why it won't blast even a single cylinder.

Any ideas are completely welcome.
Modified by wirelessnut at 11:43 AM 5/12/2009

[wirelessnut]

There is no joy at this point. The car still won't start.

The current status appears that all sensors are in good working order, we have pulse and spark, there is low compression on the drivers side of the engine. The timing belt is "loose" and may have slipped.

One shop is quoting me $450 labor (if no parts are involved) to fix the timing.

That's 6 hours labor. Is it worth it? Should I do it myself?

[yodawill2000]

If the belt is loose parts will be needed.

If your mechanically inclined it can be a weekend project.I replaced my t-Belt , Tensioners, water pump, Tstat Blah Blah Blah all over a weekend taking my time.

Used this Most excellent "how too" procedure.

zerothread?id=198122

[BruceJ30]

This happened to mine a while ago, and it turned out to be the fuel pump relay. Somehow the ground wire was getting power to it.

But i ended up just bypassing the relay and using a switch.

Just a possibility.

[yodawill2000]

Not sure that would cause the compression difference from side to side.Gotta be either intake or exhaust cam is a tad off.

[wirelessnut]

Thank you for that link, it's a super link.

I actually followed that exact procedure a while back and replaced the timing belt myself. It has reminded me of the amount of time it took to do it and was just what I needed to make up my mind. I think it was basically spread over two days and took me at least the 12 hours mentioned in the procedure.

After considering the time it takes (I don't have a free weekend coming up for a while), I decided to have the mechanic go forward with the work.

[wirelessnut]

Thanks for that info Bruce. We're getting fuel pressure, and injector pulse so the pump is running. I haven't measured the pressure but there is a decent increase in pressure when the key is turned half past ACC.

[wirelessnut]

The difference in the compression has me worried. I recall years ago I was told if a timing belt actually BROKE then pistons could slam into valves and basically trash an engine. I don't know if that's actually true, true for some, or a bald faced lie that I was told.

If the timing belt did slip, (OR BREAK) on a J30 what damage could be caused?

[yodawill2000]

The J30 has a "Interference" engine.It will thrash the engine if the TBelt breaks.But if the cam sprockets are like one tooth off it will cause what you have.

[BruceJ30]

No problem.I remember when mine did this, we did everything and couldn't figure it out. I know how it feels. Haha

[GerryO]

The difference in the compression has me worried. I recall years ago I was told if a timing belt actually BROKE then pistons could slam into valves and basically trash an engine. I don't know if that's actually true, true for some, or a bald faced lie that I was told.

If the timing belt did slip, (OR BREAK) on a J30 what damage could be caused?

If the timing belt slipped much more than one tooth, the engine probably wouldn't crank at all, but if the auto-tensioner is doing its' job that shouldn't happen. How about doing a compression check of all cylinders, as that should tell you something about the position of the timing belt?

I know for sure that the engine will not start at all when the TPS is disconnected. It will start, stumble and die fairly quickly, if the MAF is not connected both physically and electrically.

A good spark at the plugs doesn't mean that everything else electrical is OK, so an input that tells the ECM that everything is OK could be bad or you are simply lacking compression, or the proper air/fuel mixture.

I also believe in some cases you need to crank the engine longer that 10 seconds with the pedal to the floor.

[yodawill2000]

His earlier post showed the compression #'s One bank is much lower than the other.

[GerryO]

His earlier post showed the compression #'s One bank is much lower than the other.

See 'em now. Thanks.

I'd expect much lower numbers if one camshaft was out of sync, but I suppose that two on the same side could be equally out of sync causing all valves to be closed at a lower point during piston movement up and down. The oil on the outside of the plug sounds like a leaky valve cover gasket.

The engine will run on 4 cylinders (when disconnecting coil packs to checking for one bad injector/coil pack), don't know if it will run or start on only 3, but the CPS is driven by a camshaft on the diriver's side.

Check the engine timing while cranking the engine?