Engine & Transmission Post your Engine and Transmission related problems here.

4.3L, both injectors fire at idle?

Thread Tools
 
Search this Thread
 
Old Feb 17, 2007 | 07:42 PM
  #1  
RSBlazer's Avatar
Thread Starter
Joined: Feb 2007
Posts: 6
From:
RSBlazer is an unknown quantity at this point
Default 4.3L, both injectors fire at idle?

Hello. My first time posting here, can nomarlly find me over at stangnet.

I just bought a 91 S10 4x4 Blazer with the 4.3L V6, fuel injected of course. The guy I bought it from thought the fuel pump was bad, so I did some checking, and turned out that the ECM fuse kept popping due to the green injector wire being pinched. I fixed that, and bought a new injector.

Are both injectors supposed to pump fuel at idle? The reason I ask is, it's running very rough with no power. I haven't really had time to troubleshoot anything else, I just bought it and limped it home today. Any help would be greatly appreciated.

-- Rick
 
Old Feb 17, 2007 | 07:46 PM
  #2  
RSBlazer's Avatar
Thread Starter
Joined: Feb 2007
Posts: 6
From:
RSBlazer is an unknown quantity at this point
Default RE: 4.3L, both injectors fire at idle?

Another quick one, is there a way to manualy pull the ECM codes on these trucks?
 
Old Feb 17, 2007 | 08:18 PM
  #3  
Sparky's Avatar
Beginning Member
Joined: Dec 2006
Posts: 35
From: Middle Tennessee
Sparky is an unknown quantity at this point
Default RE: 4.3L, both injectors fire at idle?

To check codes on 1991 Chevy check here

http://autorepair.about.com/library/...bl-dtcs-94.htm
 
Old Feb 17, 2007 | 11:14 PM
  #4  
RSBlazer's Avatar
Thread Starter
Joined: Feb 2007
Posts: 6
From:
RSBlazer is an unknown quantity at this point
Default RE: 4.3L, both injectors fire at idle?

Anyone know about the injectors?
 
Old Feb 18, 2007 | 01:55 AM
  #5  
Kordog's Avatar
Junior Member
Joined: Oct 2006
Posts: 402
From:
Kordog is an unknown quantity at this point
Default RE: 4.3L, both injectors fire at idle?

Yes, both injectors fire at all times when the engine is running. How the ECM controls fuel flow is by how long or short the injector is held open. Korey
 
Old Feb 18, 2007 | 05:38 AM
  #6  
RSBlazer's Avatar
Thread Starter
Joined: Feb 2007
Posts: 6
From:
RSBlazer is an unknown quantity at this point
Default RE: 4.3L, both injectors fire at idle?

So if this 1 injector is not firing, even though it's new, where should I start looking for the culprit?
 
Old Feb 18, 2007 | 05:54 AM
  #7  
drperry's Avatar
BF Veteran
Joined: Jan 2007
Posts: 3,946
From: GP AB CA
drperry is a jewel in the roughdrperry is a jewel in the roughdrperry is a jewel in the rough
Default RE: 4.3L, both injectors fire at idle?

Fuses, relays, and wiring, in that order, I'm not 100% sure, but I think the injectors might each have their own fuse and relay...
 
Old Feb 18, 2007 | 01:59 PM
  #8  
Kordog's Avatar
Junior Member
Joined: Oct 2006
Posts: 402
From:
Kordog is an unknown quantity at this point
Default RE: 4.3L, both injectors fire at idle?

Well you said that you fixed one of the injector wires, I would check the other wires by the injectors. It is possible that the injector driver in the ECM got shorted when the wires got pinched. This is a pretty crude FI system. Not allot there. The injectors have constant power from the ECM fuse that kept blowng, then they are supplied a ground by the ECM. I would check the integrity of the wiring from the injector to the ECM. I would also just make sure that the new injector is not bad, I have seen that before. To check the injector driver and circuit quickly, with the injector disconnected, install a test light between the two terminals, and crank the engine.If the test light flashes then it is most likely the injector, but it still could be the driver, because the test light takes less power to fire then the injector. HTH Korey.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
oldbluechevy78
Engine & Transmission
9
Jan 22, 2014 08:17 PM
tall_ish
Lighting & Electrical
0
Nov 20, 2010 09:05 PM
amp88fan
1st Generation S-series (1983-1994) Tech
12
Feb 26, 2009 07:55 AM
BradensCreed
1st Generation S-series (1983-1994) Tech
4
Nov 3, 2008 08:36 PM
Jhop16
Steering, Suspension & Drivetrain
2
Nov 20, 2005 10:10 AM




All times are GMT -5. The time now is 12:44 AM.