LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Engine cutoff problem

Old Jan 17, 2010 | 07:18 PM
  #1  
edz97's Avatar
Thread Starter
Registered User
 
Joined: Oct 2009
Posts: 64
From: Ofallon , MO
Engine cutoff problem

I was thinking that this was a fuel pump problem because in neutral the engine will rev to the redline. When trying to drive it, the engine cuts off at 2000 rpm and needs to be restarted. I taped a fuel press gauge to the windshield and drove it. The pressure never dropped below 41 psi even when it cutoff. The only codes thrown are 102, 335,336.

Anyone have this problem or know what it could be?
Old Jan 18, 2010 | 05:16 AM
  #2  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
P0102 indicates the MAF sensor signal is less than 1,000Hz, which could mean its not functioning. Could be a problem with the pink wire in the harness connector - a common problem on the 97's. Check the pink wire for +12V (key on, engine off, harness unplugged). Measure from the pink wire to the black/white wire (ground).

The other two codes are for the crank position sensor. While the sensor is only used for misfire detection, the diagnostics are based on the sensor duty cycle, and there have been cases where problems with the Opti pulse signals have caused the CKP codes to set. Check the CKP sensor first.
Old Jan 18, 2010 | 06:23 AM
  #3  
edz97's Avatar
Thread Starter
Registered User
 
Joined: Oct 2009
Posts: 64
From: Ofallon , MO
Thanks for the detailed info.Is there a way to check the ckp or should I replace it?

Last edited by edz97; Jan 18, 2010 at 09:03 AM.
Old Jan 18, 2010 | 09:06 AM
  #4  
edz97's Avatar
Thread Starter
Registered User
 
Joined: Oct 2009
Posts: 64
From: Ofallon , MO
There is 12v present between the pink and blk/wht wires on the MAF sensor connector. I took the MAF off and sprayed MAF cleaner on it, still throwing the code.
Old Jan 18, 2010 | 12:12 PM
  #5  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
Swap it out temporarily with a known "good" MAF sensor, to see if your MAF sensor is deceased.

You are clearing the codes before rechecking them, correct?
Old Jan 18, 2010 | 03:52 PM
  #6  
edz97's Avatar
Thread Starter
Registered User
 
Joined: Oct 2009
Posts: 64
From: Ofallon , MO
Yes, I am clearing the codes.
Old Jan 19, 2010 | 09:26 PM
  #7  
edz97's Avatar
Thread Starter
Registered User
 
Joined: Oct 2009
Posts: 64
From: Ofallon , MO
I put a new MAF sensor and voila, problem solved. I still have the ckp code, will this affect passing obd 11 emissions test?
Old Jan 20, 2010 | 05:31 AM
  #8  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
If it turns on the SES light, some states/areas will not pass you. Depends on state/local inspection regulations. It won't cause any change in emissions, though.
Old Jan 20, 2010 | 05:18 PM
  #9  
edz97's Avatar
Thread Starter
Registered User
 
Joined: Oct 2009
Posts: 64
From: Ofallon , MO
Is there a way to check the connector wiring to the CKP, or is it typically the sensor that is bad?
Old Jan 22, 2010 | 05:57 AM
  #10  
Guest47904's Avatar
Guest
 
Joined: Sep 2004
Posts: 0
With KOEO, measure 12 volts from the pink/black wire to the pink wire. The yellow wire goes to the red PCM connector pin 1.

Last edited by Guest47904; Jan 22, 2010 at 06:53 PM.
Old Jan 29, 2010 | 06:34 AM
  #11  
edz97's Avatar
Thread Starter
Registered User
 
Joined: Oct 2009
Posts: 64
From: Ofallon , MO
OK, so I checked the CKP connector and have 12v there and the yellow has continuity to the pcm. I then replaced the CKP with a new one. Cleared the codes and the cel is on again. wtf
Old Jan 30, 2010 | 07:40 AM
  #12  
Guest47904's Avatar
Guest
 
Joined: Sep 2004
Posts: 0
Something to do with the mounting/contamination

Originally Posted by edz97
OK, so I checked the CKP connector and have 12v there and the yellow has continuity to the pcm. I then replaced the CKP with a new one. Cleared the codes and the cel is on again. wtf
I think it is a common problem with either the mounting or some sort of contamination. Do a google search.
Old Jan 30, 2010 | 07:44 AM
  #13  
edz97's Avatar
Thread Starter
Registered User
 
Joined: Oct 2009
Posts: 64
From: Ofallon , MO
I'll try that, thanks for your help.
Old Jan 30, 2010 | 08:49 AM
  #14  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
And is the check engine light giving your the same codes?
Old Jan 30, 2010 | 06:23 PM
  #15  
edz97's Avatar
Thread Starter
Registered User
 
Joined: Oct 2009
Posts: 64
From: Ofallon , MO
You are correct sir. I assumed that the CKP was still the culprit, but I scanned again and now codes 1641 and 1642 are present. I found a blown fuse, #7 under the hood. Must be a short somewhere. The car is running very well though. Just barely over 1/4 throttle and the rear tires want to break loose. I know the fans will not function with the problem, but its been so cold here that the temp stays below the halfway mark.

Last edited by edz97; Jan 30, 2010 at 06:29 PM.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
edman
General 1967-2002 F-Body Tech
3
Jan 25, 2015 02:41 PM
Alex Barnes
LT1 Based Engine Tech
16
Jan 24, 2015 10:21 PM
InfernalVortex
LT1 Based Engine Tech
3
Jan 17, 2015 09:35 AM
HCz28
Fuel and Ignition
1
Jan 11, 2015 11:21 AM
97z28k&N
General 1967-2002 F-Body Tech
3
Jan 9, 2015 04:58 AM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 12:08 AM.