unburned fuel, bad idle - S-10 Forum
 
LinkBack Thread Tools
post #1 of 7 Old 07-16-2015, 12:00 PM Thread Starter
Belgian User
 
Join Date: May 2015
Age: 40
Posts: 7

User is: SimonV is offline
unburned fuel, bad idle

I have 2.8V6 Tbi.

It idles bad ( after I changed the sparkplugs because it didn't idle at all anymore ) , can't seem to find leaks.

It also smokes when I accelerate or even when it's iddling. It's not oil and / or blue smoke. Really looks like fuel that doesn't get burned. Ok I might change the sparkplugwires to be sure but I don't think that's the problem. My Blazer can also run on propane and it does not seem to have problems when it does run on that.

So I do think somethings wrong with the fuel supply somehow. Any suggestions ?

SimonV is offline  
Sponsored Links
Advertisement
 
post #2 of 7 Old 07-16-2015, 12:40 PM
Maybe later.
 
tytotheler92's Avatar
 
Join Date: Aug 2011
Location: Northeast Ohio
Age: 27
Posts: 9,334

User is: tytotheler92 is offline
Garage
Send a message via AIM to tytotheler92
Re: unburned fuel, bad idle

Does it run on Propane?



I've had wayyy to many of these trucks. (Currently...on number 7)

1988 S-15 - 5.5/6 drop

1985 S10 Blazer 4WD

1998 Blazer ZR2 5 Speed!

Quote:
Originally Posted by fackinsteve View Post
3 doors for 1 and a half whores
Quote:
Originally Posted by svmcgover View Post
He only bought one wheel. So every picture we see is going to be a pic where either the rear or front is conveniently out of frame.

tytotheler92 is offline  
post #3 of 7 Old 07-16-2015, 12:45 PM Thread Starter
Belgian User
 
Join Date: May 2015
Age: 40
Posts: 7

User is: SimonV is offline
Re: unburned fuel, bad idle

Yes, seems to have no problems in that case. But I want the original fuel-system to be ok, just in case I run out of propane before I reach a gas-station where they sell it.

As soon as I switch to propane ( and original fuel-supply get's switched off ), rpm goes up and it's running fine.
SimonV is offline  
 
post #4 of 7 Old 07-19-2015, 09:26 AM
overthinker extraordinar
 
jcricket's Avatar
 
Join Date: Sep 2014
Location: littleton colorado
Age: 54
Posts: 650

User is: jcricket is offline
Re: unburned fuel, bad idle

wild ass guess, timing.
Propane has a higher octane and could run okay with advanced timing. Gas, well it would cough and sputter a bit if it was too advanced.

Like I said, WAG

good luck
mark

85 S10 Durango 2.8L extcab rwd 36k actual miles.
"true wisdom is knowing you know nothing" Paraphrased from Socrates
jcricket is offline  
post #5 of 7 Old 07-20-2015, 05:26 AM
Registered User
 
Join Date: Aug 2011
Posts: 854

User is: damanx is offline
Re: unburned fuel, bad idle

I'm curious as I don't know the technical specifics of the system for propane in conjunction with gas, but is there a different computer and injector system for that, or does the propane use the same ecm and injectors?

1985 GMC S-15 Gypsy ext cab.
3.4l, Edelbrock intake, a 4.3l throttle body controlled by an '88 TBI ECM. 700R4 with 3.73 rear. Real time tuning using a CF-30 Toughbook with a Moates Ostrich 2 emulator.
damanx is offline  
post #6 of 7 Old 07-20-2015, 09:15 AM
overthinker extraordinar
 
jcricket's Avatar
 
Join Date: Sep 2014
Location: littleton colorado
Age: 54
Posts: 650

User is: jcricket is offline
Re: unburned fuel, bad idle

sorry, I don't know. I am guessing at the timing thing too.

85 S10 Durango 2.8L extcab rwd 36k actual miles.
"true wisdom is knowing you know nothing" Paraphrased from Socrates
jcricket is offline  
post #7 of 7 Old 07-21-2015, 08:52 AM Thread Starter
Belgian User
 
Join Date: May 2015
Age: 40
Posts: 7

User is: SimonV is offline
Re: unburned fuel, bad idle

Checked the idle, maybe one degree off. That's not going to be the problem I guess.

About running on propane, it uses the same ECM. All what happens is that fuel supply is cut off and propane is injected before the throttle body.

I am starting to think I have a melted or clogged cat ? Melted because running on propane is a lot hotter. It's throwing also two codes: to rich and to lean mixture ....
SimonV is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the S-10 Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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

 
For the best viewing experience please update your browser to Google Chrome