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

1990 wont hardly run

Thread Tools
 
Search this Thread
 
Old Apr 24, 2012 | 07:44 PM
  #1  
Sam5828's Avatar
Sam5828
Thread Starter
Instructor
 
Joined: Dec 2011
Posts: 146
Likes: 1
From: Kenton Ohio
Default 1990 wont hardly run

Well it ran fine on the way to work then on the way home it stalled nd wouldn't start unless i had it at half throttle.

Once it started it was smoking black bad anymore than half or less it wouldnt run, i pulled the codes and it was 41 and 45.

says cam sensor or electronic spark timing circit open or shorted.

So where is the cam sensor located in the distributor? or is it just a bad distributor?
Reply
Old Apr 24, 2012 | 09:56 PM
  #2  
C409's Avatar
C409
Le Mans Master
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2005
Posts: 6,482
Likes: 566
From: Clearwater Florida
Default

............... Check the fuel pressure regulator for vacuum or for fuel in the vacuum hose ........ if there is fuel on the vacuum side the diaphragm is holy ...............
Reply
Old Apr 25, 2012 | 06:44 PM
  #3  
Sam5828's Avatar
Sam5828
Thread Starter
Instructor
 
Joined: Dec 2011
Posts: 146
Likes: 1
From: Kenton Ohio
Default

ok fuel injectors dont have enough power to turn on, they turn on but too low to start. is there something in the distributor that controlds the voltage to injectors?

Last edited by Sam5828; Apr 25, 2012 at 06:47 PM.
Reply
Old Apr 26, 2012 | 03:52 PM
  #4  
Sam5828's Avatar
Sam5828
Thread Starter
Instructor
 
Joined: Dec 2011
Posts: 146
Likes: 1
From: Kenton Ohio
Default

Anyone?
Reply
Old Apr 26, 2012 | 04:30 PM
  #5  
Churchkey's Avatar
Churchkey
Melting Slicks
10 Year Member
 
Joined: Sep 2008
Posts: 2,376
Likes: 111
From: Cherokee National Forest TN
Default

Did you check the FPR for a ruptured diaphragm as C409 advised? If no fuel in the vacuum hose the FPR should be ok.

Still using the stock multi tech injectors? If so they are suspect as they tend to short out. The 90 is batch fire, one malfunctioning injector can effect the operation of the others. Ohm test the injectors engine cold & engine hot.

GL
Reply
Old Apr 26, 2012 | 05:11 PM
  #6  
Sam5828's Avatar
Sam5828
Thread Starter
Instructor
 
Joined: Dec 2011
Posts: 146
Likes: 1
From: Kenton Ohio
Default

Originally Posted by Churchkey
Did you check the FPR for a ruptured diaphragm as C409 advised? If no fuel in the vacuum hose the FPR should be ok.

Still using the stock multi tech injectors? If so they are suspect as they tend to short out. The 90 is batch fire, one malfunctioning injector can effect the operation of the others. Ohm test the injectors engine cold & engine hot.

GL
I have 65# of pressure at, the rail. The noid light is dim not bright like it should be. I am assuming they are getting power just not enough.
Reply
Old Apr 26, 2012 | 05:25 PM
  #7  
Sam5828's Avatar
Sam5828
Thread Starter
Instructor
 
Joined: Dec 2011
Posts: 146
Likes: 1
From: Kenton Ohio
Default

Ohm is all good onn injectors. Now im lost. Vats is bypassed its getting spark
Reply
Old Apr 26, 2012 | 05:48 PM
  #8  
Black89Z51's Avatar
Black89Z51
Suckin' gas, haulin' ass.
Supporting Lifetime
 
Joined: Apr 2010
Posts: 1,100
Likes: 8
From: Newport News Virginia
Default

Originally Posted by C409
............... Check the fuel pressure regulator for vacuum or for fuel in the vacuum hose ........ if there is fuel on the vacuum side the diaphragm is holy ...............
Have you checked this yet?
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

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

 Joe Kucinski
story-9

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

 Verdad Gallardo
Old Apr 26, 2012 | 07:44 PM
  #9  
65Z01's Avatar
65Z01
Team Owner
20 Year Member
 
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Default

Since you have 65psi at the rail I assume the engine is "built" to take that much pressure???

That black smoke sounds like way too much fuel; is there fuel smell in the FRP vac line?
Reply
Old Apr 26, 2012 | 08:18 PM
  #10  
Sam5828's Avatar
Sam5828
Thread Starter
Instructor
 
Joined: Dec 2011
Posts: 146
Likes: 1
From: Kenton Ohio
Default

Originally Posted by 65Z01
Since you have 65psi at the rail I assume the engine is "built" to take that much pressure???

That black smoke sounds like way too much fuel; is there fuel smell in the FRP vac line?
I didnt know it had that much till tested it. It is stock all but pcmfor less chip. Like I said it has been running fine just acted up on the way home from work and started the black smoke and would only run on half throttle no more and no less. And will not start now.
Reply
Old Apr 27, 2012 | 02:02 AM
  #11  
Cliff Harris's Avatar
Cliff Harris
Race Director
15 Year Member
 
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Default

Remove the vacuum line from the fuel pressure regulator and turn on the key. If fuel comes out of the FPR then the diaphragm is ruptured. It will send fuel into the plenum and cause nasty stuff to happen (mine caught on fire).
Reply
Old Apr 27, 2012 | 01:38 PM
  #12  
Sam5828's Avatar
Sam5828
Thread Starter
Instructor
 
Joined: Dec 2011
Posts: 146
Likes: 1
From: Kenton Ohio
Default

Originally Posted by Cliff Harris
Remove the vacuum line from the fuel pressure regulator and turn on the key. If fuel comes out of the FPR then the diaphragm is ruptured. It will send fuel into the plenum and cause nasty stuff to happen (mine caught on fire).
Did that and nothing comes out.
Reply
Old Apr 27, 2012 | 02:51 PM
  #13  
Sam5828's Avatar
Sam5828
Thread Starter
Instructor
 
Joined: Dec 2011
Posts: 146
Likes: 1
From: Kenton Ohio
Default

When i turn the key over and check voltage at injector plug it is 0 but when i turn the key it is .5 volts. shouldnt it have 12 volts with the key on?

Could it be a 02 sensor since it was rich before it died completely.

Pick up coil check out at 800 ohm
has new cap, rotor, Ign control module
could it be the ECM? If so how can i check it?
each injector was 14 ohm
bypassed oil pressure switch
checked tps and it was good

Last edited by Sam5828; Apr 27, 2012 at 02:57 PM.
Reply
Old Apr 28, 2012 | 07:09 AM
  #14  
Sam5828's Avatar
Sam5828
Thread Starter
Instructor
 
Joined: Dec 2011
Posts: 146
Likes: 1
From: Kenton Ohio
Default

Anyone have any ideas?
Reply
Old Apr 28, 2012 | 07:33 AM
  #15  
Black89Z51's Avatar
Black89Z51
Suckin' gas, haulin' ass.
Supporting Lifetime
 
Joined: Apr 2010
Posts: 1,100
Likes: 8
From: Newport News Virginia
Default

If you have a FSM, start diagnosing codes 41 and 45.
Reply
Old Apr 28, 2012 | 08:11 AM
  #16  
Churchkey's Avatar
Churchkey
Melting Slicks
10 Year Member
 
Joined: Sep 2008
Posts: 2,376
Likes: 111
From: Cherokee National Forest TN
Default

It probably will not restart due to fouled spark plugs.

You have to much fuel pressure. Either the fuel return line to the tank is plugged/kinked or the FPR is not functioning properly.

Check the motor oil for fuel contamination.

GL
Reply
Old Apr 28, 2012 | 09:05 AM
  #17  
Sam5828's Avatar
Sam5828
Thread Starter
Instructor
 
Joined: Dec 2011
Posts: 146
Likes: 1
From: Kenton Ohio
Default

Originally Posted by Churchkey
It probably will not restart due to fouled spark plugs.

You have to much fuel pressure. Either the fuel return line to the tank is plugged/kinked or the FPR is not functioning properly.

Check the motor oil for fuel contamination.

GL
The injectors do not have enough voltage to turn on. They are .5 volts at cranking and 0 at key on.
Reply
Old Apr 28, 2012 | 11:17 AM
  #18  
pcolt94's Avatar
pcolt94
Le Mans Master
20 Year Member
Conversation Starter
All Eyes On Me
Photogenic
 
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Default

Check the EGR valve to make sure it is not stuck open or leaking. See if it moves smooth.

Check out and look for any broken vacuum fitting or line.

Check out the IAC, might be stuck. It might cause similar symptoms.

I was also thinking TPS was that is probably a stretch.
Reply
Old Apr 30, 2012 | 08:59 PM
  #19  
Sam5828's Avatar
Sam5828
Thread Starter
Instructor
 
Joined: Dec 2011
Posts: 146
Likes: 1
From: Kenton Ohio
Default

OK a update.

We got it running changed all the plugs and it fired up not great but it did, drove it for a little bit and seem to get better. But had it running for about 10 sec at first checked all the sensors on scan tool and the MAT sensor was reading 176* there is no way it could of been that hot car only ran 10 sec. But after we took it for a drive it went down to about 120*. So just wondering if this is bad also.

Next thing Alternator ony is reading 13 v down to 12 V. so im hoping it just got too lolw and screwed everything up and caused this mess. What do you all think?

Also one other thing my distance to empty and average mileage isnt working, DTE shows 0 and AM is showing 69

Last edited by Sam5828; Apr 30, 2012 at 09:08 PM.
Reply

Get notified of new replies

To 1990 wont hardly run





All times are GMT -4. The time now is 03:36 AM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
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-9
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