need help please!
 

just bought a 1990 zr1 and i was mislead but i wont get into that at the moment. car has 54k but i do know from my research its been sitting most of the past 8 years. the seller said it ran fine it just needed some cosmetics and he was told the injectors had been replaced but i'm not 100% sure. i unloaded the car from the shipper and it drove home 3 miles ran ok but it didn't run like a zr1 but it was driveable. i got it home and i noticed it was almost out of gas so i put some good gas in it 2 gallons along with a little seafoam. after i started it up it started running like crap, thought it may be the seafoam but the car wont even hardly move. it bogs down like it cant breathe, i figured ok it needs injectors and ill let it cool off for the night. this morning its doing the same thing put it in gear and it wants to die when you let of the clutch. could the seafoam have really made it do that? also i've noticed a loud hiss near the air filter area, it sounds like a vacuum leak but i've checked everything i could see. it could be the aftermarket intake making that noise im only use to the stock air cleaner.
any help would be appreciated for a new zr1 guy.

Re: need help please!
 

If the tank was empty and you added 2 gallons with Seafoam, you COULD have disturbed all sorts of rust/corrosion into the fuel system.

A quick fuel filter swap with an inspection of the old filters internals can reveal what you MAY have stirred up. It wouldn't be the first high pressure GM fuel filter that I have heard of being plugged or partially plugged.

Good luck my friend.

Re: need help please!
 

First not a believer in seafoam second I would have added at least 5 gals if it was that low.


You may as well remove the pumps clean out the tank change the filter add a proper amount of gas and try again for starters.

Re: need help please!
 

I had a similar problem with a 1995 that had not been run for a long time. I picked it up from the seller and drove 120 miles to Las Vegas with no problem. The next morning I easily drove up Las Vegas BLVD. Stopped and filled the tank with gas. Drove one and a half blocks and the engine stumbled and died. I barely got it back to the hotel. With help from Ted Dempsey (Thanks Ted) I replaced the injectors and the car has run fine for 46,000 miles.


Jim

Re: need help please!
 

Why not check fuel pressure at the plenum port first? ...before tearing into anything else which may introduce more unrelated problems.
Once you've determined fuel pressure issue, then you can work your way upstream to the fuel pumps and gas tank. If adequate pressure then proceeded downstream to injectors.

2 gallon / 1 bottle seafoam, is way too concentrated ...dangerous. Add 10 gallons of 93 after you've done these checks.

1990 Dark Red Metallic, only 181 made, wouldn't give up on it so quickly. Sort out the typical zr-1 issues, and you'll have a fun driving car this summer. This forum has a tremendous amount of support for owners, fixers.

My car had the fuel pump hose clamp loosen and fall off. It sputtered and quit. Took me half the day to figure it out, easy fix, after a few phone calls. Thanks to Marc Haibeck, got me running again!

Re: need help please!
 

PicturesAttachment 7589Attachment 7590

Re: need help please!
 

My car had the hose come off the fuel pump. Thought it was a computer issue. Would crank up them die. The plastic clamps
They use are crap. Stupid idea. I went to metal hose clamps and haven’t had any issues with that again.


Sent from my iPhone using ZR-1 Net Registry

Re: need help please!
 

The correct spec for fuel pressure at WOT or Vacuum Referenced Fuel Pressure Regulator disconnected, is 50.8 psi(350kpa) for the LT5. At idle it should be a bit less.

Re: need help please!
 

I had the same issue, car sputtering and stalling. Hose got disconnected from the fuel pump and corrected the problem with SS hose clamp.

Re: need help please!
 

Well i checked the fuel pressure and its right under 50 so i guess im looking at injectors.