need help please! - ZR-1 Net Registry Forums

sljs3413 · 06-04-2018

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.

Hog · 06-04-2018

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.

We Gone · 06-04-2018

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.

QB93Z · 06-04-2018

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

George Maz · 06-04-2018

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!

George Maz · 06-04-2018

Pictures20160616_175440.jpg 20160617_155036.jpg

KFoster · 06-05-2018

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

dredgeguy · 06-06-2018

Quote:

Originally Posted by KFoster

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

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

Hog · 06-05-2018

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.

sljs3413 · 06-09-2018

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

06-04-2018	#1
sljs3413 Join Date: Oct 2016 Location: nashville, tn Posts: 33	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. Last edited by sljs3413; 06-04-2018 at 12:19 PM.

06-04-2018	#2
Hog Join Date: Jul 2010 Location: Woodstock, Ontario, Canada Posts: 1,275	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. __________________ peace Paul ZR-1 Net Registry Member #1494

06-04-2018	#3
We Gone Join Date: Apr 2004 Location: ATL. GA. Posts: 2,170	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. __________________ Steve 1990 Steel Blue/Black #2355 1990 Red/Red #1473 1991 Quasar /Black #118 Sold 1991 Turquoise/Black #766 Parted Out 1993 Yellow/White #179 Sold 1990 Black/Gray #1361 Headers/4:10s Sold

06-04-2018	#4
QB93Z Join Date: May 2007 Location: Westminster, Maryland Posts: 3,689	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 __________________ If it isn't fun, you aren't doing it right! 1990 Black ZR-1 - sold 1993 Quasar Blue ZR-1 1994 Competition Yellow ZR-1 1995 Dark Purple ZR-1 Maryland State Coordinator WAZOO Member

06-04-2018	#5
George Maz Join Date: Dec 2014 Location: Long Island, NY Posts: 295	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! __________________ 1990 ZR-1 #1587 1990 ZR-1 #1727 Last edited by George Maz; 06-04-2018 at 10:51 PM.

06-04-2018	#6
George Maz Join Date: Dec 2014 Location: Long Island, NY Posts: 295	Re: need help please! Pictures20160616_175440.jpg 20160617_155036.jpg __________________ 1990 ZR-1 #1587 1990 ZR-1 #1727

06-05-2018	#7
KFoster Join Date: Jan 2015 Location: Decatur, AL Posts: 93	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 __________________ 1990 ZR1, 1987 Mustang GT (since new), 1973 DeTomaso Pantera, 1987 928S4 Passed on: 1984 930S (gray market), 1988 Mustang Coupe Trooper car(drag)

06-05-2018	#9
Hog Join Date: Jul 2010 Location: Woodstock, Ontario, Canada Posts: 1,275	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. __________________ peace Paul ZR-1 Net Registry Member #1494

06-09-2018	#10
sljs3413 Join Date: Oct 2016 Location: nashville, tn Posts: 33	Re: need help please! Well i checked the fuel pressure and its right under 50 so i guess im looking at injectors.