C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Randomly dies

Thread Tools
 
Search this Thread
 
Old Sep 24, 2017 | 10:17 PM
  #1  
Mike Kamholz's Avatar
Mike Kamholz
Thread Starter
Racer
 
Joined: Feb 2016
Posts: 319
Likes: 4
Default Randomly dies

This just started 2 days ago I was decelerating and the engine just stoped. There was power to everything and I was able to start it up before the car got to the stop sign. It has happened 3 times not all at low speed and will start right up. 88 corvette. Any help would be nice. Oh by the way. The tank had about 1/4 left
Reply
Old Sep 25, 2017 | 06:31 AM
  #2  
billschroeder5842's Avatar
billschroeder5842
Zen Vet Master Level VII
Supporting Gold
Veteran: Navy
10 Year Member
Liked
Loved
 
Joined: Mar 2016
Posts: 5,214
Likes: 1,173
From: Southlake, TX
Default

When it dies, does it feel more like it is running out of gas or does the ignition just cut out and do the dash light stay on after it dies,

This will tell us if it is more electrical or fuel related.
Reply
Old Sep 25, 2017 | 06:46 AM
  #3  
Mike Kamholz's Avatar
Mike Kamholz
Thread Starter
Racer
 
Joined: Feb 2016
Posts: 319
Likes: 4
Default

Everything stays on lights radio all good. Just stops and continues to coast. But will fire right back up. There is no lunging or hesitation just cuts out.
Reply
Old Sep 25, 2017 | 09:16 AM
  #4  
Mike Kamholz's Avatar
Mike Kamholz
Thread Starter
Racer
 
Joined: Feb 2016
Posts: 319
Likes: 4
Default

Any chance it could be the fuel pump cutting out what would that look like??
Reply
Old Sep 25, 2017 | 09:35 AM
  #5  
billschroeder5842's Avatar
billschroeder5842
Zen Vet Master Level VII
Supporting Gold
Veteran: Navy
10 Year Member
Liked
Loved
 
Joined: Mar 2016
Posts: 5,214
Likes: 1,173
From: Southlake, TX
Default

If it only happens on deceleration, my guess is that it is the fuel pressure regulator. The FPR is vacuum operated (adjusted actually) and the decrease in engine rpm lowers the vacuum, closing the FPR and limiting the fuel flow.

Acceleration and normal speed apparently gives tyour FPR enough to "hold" steady. If the car accelerates normally and drives steady just fine my guess is that your pump is doing its job.

You can always check your fuel pressure and bench tests the FPR with a gauge. Put the gauge on the schrader valve and increase the speed at idle. Keep an eye on the the pressure. Then release the throttle to idle and see what the pressure does- it should remain pretty steady.

Just my guesses at this time...
Reply
Old Sep 25, 2017 | 10:31 AM
  #6  
Mike Kamholz's Avatar
Mike Kamholz
Thread Starter
Racer
 
Joined: Feb 2016
Posts: 319
Likes: 4
Default

Ok I will give it a try thanks.
Reply
Old Oct 1, 2017 | 10:10 PM
  #7  
Mike Kamholz's Avatar
Mike Kamholz
Thread Starter
Racer
 
Joined: Feb 2016
Posts: 319
Likes: 4
Default

Ok have not checked the fuel pressure yet. But did replace the ICM as I have read they they can go out. So far 40 miles and all good.
Reply
Old Oct 2, 2017 | 08:34 AM
  #8  
81c3's Avatar
81c3
Le Mans Master
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2005
Posts: 8,552
Likes: 935
From: Communist Colorado
Default

My guess is you added more fuel to the tank....???? If you did, maybe the problem is in the fuel tank at the rubber fuel line connecting the hard line of the fuel assembly unit to the pump itself. Its about a 4" section of fuel line that could be split.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-1

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-2

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-3

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-4

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-5

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-6

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-7

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-8

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
story-9

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
Old Oct 2, 2017 | 09:34 AM
  #9  
JasBass's Avatar
JasBass
Racer
All Eyes On Me
Liked
Loved
Community Favorite
 
Joined: Jun 2017
Posts: 343
Likes: 18
From: Newport News VA
Default

I went through this exact same situation with my 89. Car would run amazingly strong as long as I was cruising or getting on it. As soon as I would let off and put the clutch in to cruise, RPMs would just trickle down and stall out, electronics all still on and would fire back up. I tracked it down to a bad FPR, pressures would drop under acceleration and then fall more once it let off. Pressures in the rail would bleed down to 0 within minutes. I replaced the FPR and pump since they were both original pieces. All in $70 fix and an afternoon of time.

I had a friend of mine with an L98 vette that had a similar issue as well. Turns out multiple of his original Multec injectors were sticking and creating a rich condition at lower RPMs and stalling the car. Just more food for thought.

I'm curious about the ICM fix though, my next project is replacing the electronics in the distributor. My idle gets a little lumpy after some heat gets in the engine.
Reply
Old Oct 2, 2017 | 01:50 PM
  #10  
Mike Kamholz's Avatar
Mike Kamholz
Thread Starter
Racer
 
Joined: Feb 2016
Posts: 319
Likes: 4
Default

Originally Posted by 81c3
My guess is you added more fuel to the tank....???? If you did, maybe the problem is in the fuel tank at the rubber fuel line connecting the hard line of the fuel assembly unit to the pump itself. Its about a 4" section of fuel line that could be split.
Yes I did but it died several times even after having more fuel it.
Reply
Old Oct 3, 2017 | 02:09 AM
  #11  
Hot Rod Roy's Avatar
Hot Rod Roy
Safety Car
15 Year Member
 
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
Default

Originally Posted by billschroeder5842
If it only happens on deceleration, my guess is that it is the fuel pressure regulator. The FPR is vacuum operated (adjusted actually) and the decrease in engine rpm lowers the vacuum, closing the FPR and limiting the fuel flow.
Bill, the problem may be the FPR, but we have a slight technicality here. The FPR is on the return side of the fuel path, so the FPR opens to reduce the fuel pressure, rather than closes. In the old carburetor days, with no return line, the FPR was on the supply side, so that was different.

In our 'vette's, closing the FPR would increase the fuel pressure.

Mike, we need to see the results of your fuel pressure test, and how soon does the pressure drop off?

Reply

Get notified of new replies

To Randomly dies





All times are GMT -4. The time now is 07:01 PM.

story-0
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-1
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-2
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-3
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-4
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-5
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-6
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-7
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-8
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-9
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE