New ZR-1 owner...no start

[Jalisurr]

Hey folks,

So I recently got my new (to me) 1990 ZR-1, and it worked fine for a couple days, then today as I was driving, the engine suddenly died, like someone had turned off a lightbulb, no stumbling, nothing. Now it will crank but not start.

I can hear the fuel pump prime, and it won't start at all, so I don't think it's that the primary fuel pump has failed.

I tested spark and found that most of the spark plugs had spark but I couldn't get anything out of 2 of them. So my guess is that one of the coil packs has gone bad? Is the LT5 a high enough compression motor that it won't fire at all with one bad coil pack?

Just looking to confirm my suspicions before I go tearing into the thing. Those coils are buried way in there.

[Jalisurr]

Quick update, I did the fuel pump test with the probe at the front of the car and it gave around 9.5A, so both fuel pumps are operating. This car has also had the injectors replaced with Bosche ones.

So I'm definitely thinking coilpack, while simultaneously hoping you guys will tell me it's something simple. (I've checked all the fuses though)

[Jalisurr]

One more update, checked ECM and CCM codes just now and didn't get anything. Don't know how relevant that is.

[Z51JEFF]

The car will run on 6 cylinders at least on a 91 it will can't expect a 90 to be any different. I'd start at fuses and go from there,a 91 won't start if the ABS fuse is blown. Regardless of what it is you will have an answer from someone here or the other Forum.

[Jalisurr]

Ok, appreciate it. I thought that the way it cut out felt like an electrical thing, fuses or something. I did a quick once over on them but I'll take another look.

[GOLDCYLON]

Do you have fuel in the tank ? Not just what you fuel guage reads. May have a stuck sending unit. Suggest adding a gallon and see if it runs since you state you are hearing the fuel pumps.

[Jalisurr]

Appreciate the thought, but unless the ZR-1 gets waaaaay worse fuel economy than I thought, the fact that I put 13 gallons in the tank about an hour before it died should mean it had plenty.

[GOLDCYLON]

Is fuel getting to the rails? What is the Pressure?

Then move onto are you getting spark ?

[Jalisurr]

Ok, you were right to continue looking at fuel first. There doesn't appear to be any pressure at the rails, I can push in the schrader valve and nothin comes out. But as stated, I can hear fuel pump priming noises when I turn the key on, and it pulls 9.5A to the fuel pump tester. Any suggestions where to look?

[We Gone]

I wonder if the fuel line on the primary pump to the the fuel line came off??

[Jalisurr]

That's going to be my next thing to check. I would have expected to notice a puddle of gas somewhere if that was the case though?

[We Gone]

That's going to be my next thing to check. I would have expected to notice a puddle of gas somewhere if that was the case though?


The pumps are in the tank.

http://www.zr1.net/forum/showthread.php?t=9778

[Jalisurr]

Oh, I see, you are thinking one of the hoses inside the tank came off? I just checked the hoses outside and they all look good (see attached). I'll pull the pump assembly out and check the ones inside.

[We Gone]

Its just a guess but if you have a bad pump they have to come out anyway, good luck.

[Demps]

Buy a $40 fuel test gauge at an auto parts store.

Connect it to a schrader valve on fuel rail.

[Both pumps run momentarily on initial key turn--only primary energizes during start sequence and low demand.]

Turn key to energize pumps.

Do you have pressure--sounds like noise but no pressure.

Remove primary fuel pump fuse from passenger fuse panel.

Turn key--do you have pressure? If yes, secondary pump works. If no, secondary pump failed.

Replace primary fuel pump fuse.

Remove passenger kick panel (fuse panel bezel first)

Remove secondary fuel pump fuze under dash.

Turn key--primary pump pressure?

[mike100]

You can get a spark plug checker on one plug wire and test for spark when cranking. Also Carburetor cleaner combusts about the same as gasoline. have a helper spray some in the intake boot while you crank it and if it is a fuel issue, it will fire right up. If you are like me, you already have a can somewhere.

[Dynomite]

You can get a spark plug checker on one plug wire and test for spark when cranking. Also Carburetor cleaner combusts about the same as gasoline. have a helper spray some in the intake boot while you crank it and if it is a fuel issue, it will fire right up. If you are like me, you already have a can somewhere.

Good stuff there Mike :handshak:

[Jalisurr]

We Gone got it, the output hose had come off inside the fuel tank. Clamped it back on and it fired right up!

All good folks, reattaching the permagrin now.

[GOLDCYLON]

And there we have it. Well done gents :cheers: