Engine died

[A_J]

Hi

Had my 91 out for a spin today in beautiful weather. But on my way home when i shifted from 2nd to 3rd she died on me. As we were still rolling i tried to jump start her by releasing the clutch but she wouldnt start. Tried to crank her when we stopped but no luck with that either.

Pulled one coil and plug to check for spark and there was, I know she's getting fuel because it fired in the exhaust when I tried to start her when it was
still warm.

Is it possible the timing belt could have jumped a tooth or two?

BTW. No engine light or codes.
:frown:

 

[TitaniumVtec]

How old is your timing belt?

 

[Larry Bastanza]

Check the main relay. When you first turn the key to "on", the fuel pump should run for a little while. The pump is behind the drivers seat(US Verison left hand drive). If you hear nothing, it is likely that relay.

This would not be the first time I have seen this, last year at NSXPO2009, first night, we had a car, same symptoms(no fuel pump sound), swapped relay, fired right up.

It is clear also you have a fuel problem, since you mention you have spark.

HTH,
LarryB

 

[A_J]

Thanks for quick replies.

Timing belt is about 40k km and 4 years old.

Fuelpump is running for a short while after turning the ignition on.

 

[pgilliam1]

Very doubtful it's your timing belt unless it broke completely. If that happened you'd be hearing awful engine noises. Once the Tbelts run OK they usually stay that way unless the tensioner or harmonic balancer goes. Pull your return fuel line off (it's just clamped at the end of the rear fuel rail), put another hose on the fuel rail and run it into a gas can, milk carton, etc. and have someone turn your key on and off and see if the fuel is pumping through (be careful of splashing - there's about 40 psi there). Maybe your fuel system got clogged with some bad gas pumped out of the bilge of a station tank? How many miles on your fuel filter?
If you have spark at the plugs - the next thing you need is fuel.
Happy Motoring!

 

[drew]

If the engine is cranking: I would give some attention to the Main Relay, despite your fuel pump priming....it is a complicated relay that can fail in many ways. Give it a whack or replace it. I'll bet your ECU is not getting power...

If you are really concerned that you slipped a timing belt (unlikely), just check the compression on a few choice cylinders. If you are within compression range, you are just fine.

Drew

FWIW: I have a new MR in my trunk, it is field replaceable without tools and the ignition key aides in removing the connector.

 

[A_J]

Again, thanks for replies.

Checked the fuel rail return line, there is fuel coming out as the pump is priming.

My suspicions toward the timing belt was strengthened today when I got the car up on stands and went underneath for a closer look. The crank pulley (aka. harmonic balancer) have come loose and eaten its way into the timing belt cover, there was pieces of melted plastic sticking to various parts under there and i could see straight into the TB pulley.
I have read most of the posts here on prime regarding that part so I inspected it just 2 months ago when I took the car out from winter hibernation. It looked fine then as far as I could see with both mirror and by "feel" (no cracks in the rubber part).
It looks like the whole inner rubber part has come loose from the pulley, but is still in one piece and held in place by the axle.

I guess I'm lucky it didnt end up worse.

 

[A_J]

 

[Hugabuga]

A_J, something worries me: the 2 belts driven by the "harmonic balancer" are for the AC and the alternator, none of this should be responsible for an engine STOP and dont' explain why it doesn't start anymore

Have you check if part n.9 is there??

Without the screw n.8, the small key n.9 won't last very long due to vibrations etc...and if it brakes, the timing belt drive pulley n.5 would spin freely in the crankshaft axle!!
I sincerely hope this is not the problem, verify part n.9, and most of all do not try to start the engine anymore prior to put the crew n.8 in place!!
Has it broken or unscrewed itself out? is there any part of it still screwed in the crankshaft?

 

[pgilliam1]

AJ, you're a lucky man. I've seen pictures of the HB's coming apart and ripping and tearing things to pieces. You're not the first and won't be the last to have this happen. I said it before; Guys, replace your harmonic balancers if they have over 100K miles or are 15 years old or older. They're a known defect and it's not worth the gamble on an interference engine. My $.02. Happy Motoring!

 

[Hugabuga]

Have you read this A_J?
http://www.nsxprime.com/forums/showthread.php?t=75746&highlight=harmonic+balancer
You seem to have a broken or missing screw and a broken harmonic balancer at the same time, as it appears to be in your pictures!!!

 

[A_J]

Have you read this A_J?
http://www.nsxprime.com/forums/showthread.php?t=75746&highlight=harmonic+balancer
You seem to have a broken or missing screw and a broken harmonic balancer at the same time, as it appears to be in your pictures!!!

Yep, I've read that and other posts regarding the harmonic balancer during the winter, and I inspected min before I took it out from winter storage. The bolt you refer to is intact. As I see it, if that bolt breaks the whole assembly will come loose.

Sad thing is I was aware of the harmonic balancer's "fragility" and I tried to order one of Autoweave's improved ones, but they only takes orders by phone and thats kinda complicated from the other side of the world with the time difference and all.

Anyway, as I said, I guess I'm lucky it didnt end up with the timing belt breaking down completly. Hopefully theres no bent valves or valvestem's.

 

[Hugabuga]

You can easily check if the timing belt has jumped a tooth or not: remove one cover and place piston 1 at TDC and verify the marks in harmonic balancer and camshaft pulleys... if only one tooth has jumped, maybe nothing happened and you are very lucky , or even better, you have an electronic problem in your car that has nothing to do with timing belt and harmonic balancer breakdown!

 

[R13]

If the balancer ate through the timing cover and kicked the belt you will want to replace the belt anyway, so you may as well go that direction and have the other stuff checked out while it's all apart.

As you're putting it back together, pick up one of TitaniumDave's balancer shields and rest easy. IMO this is a mandatory modification having experienced the balancer disintigration thing myself.

 

[A_J]

The cause of my problems:

This piece of the TB cover has obvious marks of the TB teeth

What the harmonic balancer did to my TB cover:

 

[R13]

Yeah, I was lucky that my belt did not ingest any of the plastic shavings. I was spent probably an hour with an air hose, mirror, and flashlight making sure there were no pieces left behind when I replaced the timing cover. Have you determined if your valves and such are ok, or do you have a project on your hands?

 

[Hugabuga]

So A_J did your engine really died?
You found the cause, but what is the consequence? As you said the engine stopped and won't start again...
Have to checked the pulleys timing marks? did the TB jumped any teeth?

 

[ChopsJazz]

My harmonic balancer will arrive tomorrow. I will not drive the car again until it gets here, and then only to take it to the shop for replacement.

I'm sorry to hear about your HB failure.

 

[scotchtzd]

this thread scared me. so i got a new HB and also installed the shield from science of speed. took me less than a hour to from start to finish. Pretty easy DIY

 

[A_J]

So A_J did your engine really died?
You found the cause, but what is the consequence? As you said the engine stopped and won't start again...
Have to checked the pulleys timing marks? did the TB jumped any teeth?

You're right Hugabuga, I'm not 100% sure of the consequences yet.
Strange thing is, the front cams and the crankshaft lined up perfectly, but the aft cams was off by two tooth's each. I cant see any marks on the pistons using a SeeSnake , but that wont bend enough to see the valves so I'm not sure they are not damaged.
I'll let you all know when i get it started again. Awaiting some parts to arrive from the US, including Titaniumdave's HB shield

 

[ChopsJazz]

Just an update: I installed my new harmonic balancer this week. The old one was in perfect condition after 152K miles, but now I have one less thing to worry about.

 

[R13]

Just an update: I installed my new harmonic balancer this week. The old one was in perfect condition after 152K miles, but now I have one less thing to worry about.

You can never be too certain. I had a very reputable NSX tech tell me that nothing looked wrong with my old one a couple of months before it came apart, and I had also visually inspected it on the car about a week before it went and nothing looked out of the ordinary. It's one of those things, like a timing belt, where any non-destructive inspection is useless.

 

[Hugabuga]

I was just thinking about that harmonic balancer...
Why did they bound that rubber part to the harmonic balancer in the first place?? was it to absorb what? some vibrations?? from where?? and why didn't they bound it on the external side of the HB instead?
It seems to me that the benefits clearly do not compensate the risks of failure....so why don't we simply remove the rubber from it before it fails and hits the timing belt??
I don't believe the engine or its crankshaft will fail just because there is no rubber in the HB, as it doesn't fail when you replace the flywheel for a lighter one!
Imagine that poor rubber at 8000RPM...all the stress, aging, heating and deformation....that is crazy!!
I think I will remove the rubber from mine and that's it:biggrin:

 

[Thunder]

no, do not remove rubber, it absorbs the shock of compressor A/C and it filters the vibrations harmonic of the crankshaft, it protects the connecting-rod bearings, if you remove rubber, the bearings will be destroyed much more quickly

 

[Hugabuga]

I understand your concern, if Honda engineers decided that rubber was needed of course there must be a reason....HOWEVER...I have doubts that they thought about the risk to hit the Timing Belt in case of failure.
If idea was just to absorb the A/C shocks they would bound it in the AC compressor instead, but I agree to use it as a crankshaft damper to reduce its harmonic twisting angle.
Does the S2000 engine also have this rubber? How long would last the engine without it?
A F1 engine does not use a HB at all, because they have no AC compressor or belt driven alternator in the first place:biggrin:....but of course they are designed to last just a couple of hours or so....