94 Suburban Misses at a cold start

Reply

  #1  
Old 09-11-05, 10:08 PM
jpotts461
Visiting Guest
Posts: n/a
94 Suburban Misses at a cold start

I have had this vehicle 7 years. It has had the same problem since I bought it. Sluggish at take off and missing like it is flooded at a cold start. It runs great on the highway. It is a 350 AT 3/4 ton TBI. If I run injector cleaner through it several times it does better but not great. It has been semi retired to pulling boats and I need the lower end torque especially at the ramp with a boat on and a cold engine. Ideas???
 
Sponsored Links
  #2  
Old 09-12-05, 04:43 AM
the_tow_guy's Avatar
Group Moderator
Join Date: Feb 2001
Location: SW Fla USA
Posts: 11,515
The better performance after the injector cleaner could be coincidental. Have you checked/replaced everything on the ignition side to eliminate possible causes? Distributor cap & rotor and plug wires especially. Also check for any stored codes, even if the check engine light is not currently on. On that year vehicle you can pull the codes yourself by jumpering pins in the test connector.
 
  #3  
Old 09-12-05, 07:41 PM
jpotts461
Visiting Guest
Posts: n/a
I had previously replaced all ignition components with no improvement in low end performance. I have not pulled any codes because the MIL lamp has never illuminated. I guess that is my next step. I need to look up how to pull the codes. I think I might have a reader for the car somewhere.
 
  #4  
Old 09-13-05, 03:09 PM
BuzzCut
Visiting Guest
Posts: n/a
Check fuel pressure regulator.
 
  #5  
Old 09-13-05, 04:52 PM
Flux-engineer
Visiting Guest
Posts: n/a
Are you sure it is running rich on cold start up? Do you smell excess fuel or see excess blue smoke from the exhaust? You may have a lean issue....
 
  #6  
Old 09-13-05, 07:36 PM
Member
Join Date: Nov 2001
Location: North Texas
Posts: 2,345
question

does the CEL come on at all even for test like when you turn on the key with no start?
 
  #7  
Old 09-13-05, 10:08 PM
jpotts461
Visiting Guest
Posts: n/a
I read about the fuel regulator causing this in other vehicles.

Lean or rich ? I believe it is a lean condition due to the fact I do not smell gas. On a conventional carburated engine I would add more choke and see if it solved the problem.

CEL lamp at start? Had to look that up . Check engine light.(service engine soon) Let me go see. Have a service engine light and check guages plus abs at turning ignition to on.

I plugged in a GM tester and all I got was the code 12. (system Pass - self diagnostic)
 
  #8  
Old 09-14-05, 03:02 AM
Join Date: Jun 2002
Location: Long Island, NY
Posts: 1,531
I would look into the heated air intake system if it has one.
 
  #9  
Old 09-14-05, 08:46 AM
jpotts461
Visiting Guest
Posts: n/a
I believe it does have one. It will give me a few other items to look at other than the normal stuff which did not work the last time I tried to get the low end sputtering out. It is hard to throw money at it when it goes away after the engine is warm.
 
  #10  
Old 09-14-05, 09:01 AM
Join Date: Jun 2002
Location: Long Island, NY
Posts: 1,531
Also the cross over passage under the TB base (exhaust is transferred across the bottom of the manifold) to warm the manifold floor.

There may also be some type of heat riser or valve on the exhaust to direct exhaust through the cross over
 
  #11  
Old 09-18-05, 02:13 AM
jpotts461
Visiting Guest
Posts: n/a
Smile

Originally Posted by toyotaman11769
I would look into the heated air intake system if it has one.
Found some vacume leaks. The heated air intake was missing its hose, so I removed spring to let butterfly open. I will check today on the hose. It seems a heated intake for starts controlled by the thermal couple should help with cold start acceleration. It appears to run much better now with the butterflys taped open. But it is hot here in Texas and in the winter I know a heated manifold should help.

Thanks and I will let you know.
 
Reply


Thread Tools
Search this Thread
Display Modes
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 05:29 AM.