Nacho_ZR1

So I barely purchased this car a few days ago. I've only driven it pretty hard through gears 1-3 since I've been waiting to do an oil change and tuneup next weekend.

A friend of mine wanted a ride earlier today so I took the car to a very dark quiet street and took off. The car pulled very hard in first gear and began to fishtail around 6500 rpm so I short-shifted into second gear and kept going. Everything was fine until I let off the gas and made a U turn to come back home. The car was idling extremely roughly and it was sluggish to get through the gears. I took her home and let it sit for a few minutes. When I tried starting the car back up, it cranked for at least 10-15 seconds and a big puff of grey smoke came out of the exhaust. I am afraid to take the car for a spin again and not sure what to think. Bad fuel pump or injectors? Am I off base? Not sure if the delaership put in a fresh tank of gas or if it's still the old gas that was from the previous owner.

Not sure what to think but I'm hoping you all have seen this before?

JetJock

Is the car still able to start and drive? I don't jump on the pedal with this thing because there is so much power back there and I don't know what the previous owner did to it, if anything. When I drove it, it got up in there with the acceleration but you do have bad fuel injectors, I'm thinking. The fuel may have been old, too. Anybody else want to jump in on this?

The car sat for a long time and bad things can happen to a car like that. That car has two fuel pumps: one for the normal ops and the second for the secondaries fuel injectors. If the primary fuel pump quit, you aren't going anywhere.

Graybeard ZR1

You "short shifted" at 6,500rpm. You're going to love ZR-1.

It would be nice if it was just old crappy gas. I'd change the oil, filter, and gas filter. then put some fresh premium in there, along with a bottle of "gas treatment" (chevron is good), and then get out on the interstate for a little therapy.
140 in fourth gear will make it sing.

But...but Officer, we're just testing for a fuel problem

Nacho_ZR1

lol!

Mr. Gizmo

How many miles does this zr-1 have and how long was it sitting before you took ownerhip?

You may have blew vacuum lines off that are under the plennum. First thing i would do is some maintenance and cleaning under the plennum.

Another issue was the secondary butterflies in the ports for the secondaries may not be operating correctly. There was a problem on many of the 90 and 91 cars where the actuator were installed backwards, causing the butterflies to bind and not open. I had this problem on my 91. I think this was corrected by 92 production run.

Nacho_ZR1

So, I had a nice phone conversation with JetJock and am feeling better already I walked out to the car earlier today and it had a very strong fuel smell coming from under the hood. I didn't see anything out of the ordinary but when you look under the car, you can see it is leaking gas! There was about an 8-10 inch diameter puddle where the gas has been dripping all night. I put my finger on the oil pan and it is still dripping fuel slowly.

Blown injectors?

VetteMed

Bad injectors shouldn't cause leaking of fuel outside the motor - and if they've leaked down so much fuel that it's leaking fuel from the oil pan gasket, then that should be apparent on the oil dipstick. Excess fuel leaking past the piston rings and into the crankcase could dilute the oil, and if enough fuel got in the oil, it could raise the oil level above the top of the pan, and seep through the pan gasket. HOWEVER, I think that's pretty unlikely, and would suspect that a fuel line is leaking, perhaps an o-ring in the fuel rail assembly, but I don't think that's a typical sign of a bad injector.

Nacho_ZR1

So if I buy new injectors, am I covered in the o-ring / rail department or is that an additional purchase?

VetteMed

I would first diagnose the problem before ordering parts... I'd suggest getting under the car, looking at the fuel lines under the passenger side rocker panel, into the fuel filter, and then into the rubber lines that run from the filter up to the fuel rails. There are multiple o-rings preesnt, not just the o-rings at the injectors. Jerry's Gaskets sells all of the fuel system o-rings, and it's certainly a good idea to change them on a 20 year old car (I did mine recently), but It's also possible that the rubber lines could be leaking. Could also be a bad fuel pressure regulator.

Nacho_ZR1

Point well taken. I am anxiously awaiting to meet up with JetJock and go over the car with a fine toothed comb

JetJock

After reading this posting and talking to Carlos, I think that the o rings were blown out. The injector housing, the fuel lines and fuel rails have too much strength in them for a part to go like that. Basically, just need to look the car over again like Evan and I did last time and check out our notes. The car does have issues and it won't be a one stop fix. But until the plenum is pulled and we get a good luck at everything, it's all conjecture. However, I do think injectors and spark plugs would help as the car hasn't had any mtx in a very long time. It sat for a very long time from 2005 up until this year. Only was driven maybe a 1,000 miles in five years. It could be a lot of things. The fuel regulator may have blown the diaphragm. That has happened on another Vette that I know and got fixed. We'll find out and fix it. The fuel lines are stainless steel. Have to be for the pressure.

Neyl

If you decide your issue is injectors, let me know. I have a complete set (16) of Multecs that completely gone through by John Banner at The Fuel Injector Connection. Cleaned,flow-tested,new filters,new o-rings etc. I'll sell for $225.00 & will ship free to the lower 48 by USPS.

Nacho_ZR1

thanks!

VetteMed

That's a screamin' deal for sure. Keep us posted on the troubleshooting...

JetJock

I talked to Jon and he highly recommended not using Multecs if you plan to drive the car. Multecs are NOT compatible with ethanol. He uses Delphi's. They are good with ethanol. Multecs are only to be used with gas that does NOT have ethanol or you don't plan to drive it such as NCRS. These cars were designed for gas not corn.

VetteMed

Good point... I am running the FIC Bosch reconditioned injectors, I must have missed the "Multec" part in the post.

JSki9299

I think I test drove your 92 a couple weeks ago at the dealership in Irving TX. This is not related to your fuel issue but I noticed that the radiator hose is about to fail on the car. When you rev the engine you will see the radiator hose blow up like a small balloon. It almost doubles in size at about 3000 rpm. If you need any further help please let me know. I did all the work on my 91 ZR-1 about 4 years ago. I have a list of vendors for rebuilding the stereo, amps, shocks, fuel injectors etc.

Nacho_ZR1

JSki, you are 1000% correct! When I last drove the car, I popped the hood and saw that the radiator hose looked as if it had swallowed a few hamsters! I backed away from the car fearing that thing would pop and scorch me at any given moment.

I called Mark Haibec yesterday as a matter of fact. I have 6 new hoses and a performance chip headed my way :-)

JetJock

The one thing that I like about these engines is that they are built stout. You can destroy them but you have to be doing something really stupid to do that. I think that once we get the plenum off, check the stuff underneath and check out the fuel system and replace the hoses, etc., he'll have a real nice car. The car was neglected for a long time.