Search | Car Forums | Gallery | Articles | Helper | AF 350Z | IgorSushko.com | Corporate |
| Latest | 0 Rplys |
05-16-2005, 07:49 AM | #1 | |
AF Newbie
Join Date: May 2005
Location: st louis, Missouri
Posts: 44
Thanks: 0
Thanked 0 Times in 0 Posts
|
Misfire?
Ok, my scenario is that I recently purchased a 1990 GMC Jimmy 4.3 4wd with a little over 140k miles. I notice at speeds of 60mph or more when accelerating, I hear a slight knock. As of last night, when accelerating, I notice a "sputter" where the engine stalls briefly (leading me to believe that it's one cylinder that is acting up), accompanied by a knocking. The fuel mixture is obviously rich, as my tail pipe is carbonized at the tip. The plugs are old, as are the wires (all things that I just haven't gotten to yet) and the air filter is dirty, but not dirty enough to cause a major issue. No check engine light (so I'm assuming no codes). Any suggestions?
|
|
05-16-2005, 08:39 AM | #2 | |
AF Enthusiast
|
Re: Misfire?
Do a tune up, replace your ignition module (use lots of dialectric grease) If that doesn't help, I would start looking to the cat. You say you have a lot of soot at the tail pipe, well, it has to go through the car first and it may be clogged. Also check your injector flow. They should be firing an nice cone. If they are dripping what so ever, replace them.
__________________
95 s10 Blazer, EGR Mod, ZQ8 Steering box mod, 99 Center console shifter mod and more... See everything at www.pghconsulting.net/teal |
|
05-16-2005, 08:48 AM | #3 | |
AF Newbie
Thread starter
Join Date: May 2005
Location: st louis, Missouri
Posts: 44
Thanks: 0
Thanked 0 Times in 0 Posts
|
Forgot to mention fuel smell on the dipstick.
|
|
05-18-2005, 06:12 PM | #4 | ||
AF -Advisor
Join Date: Sep 2003
Location: Sudbury
Posts: 13,565
Thanks: 0
Thanked 1 Time in 1 Post
|
Re: Misfire?
Quote:
Get the engine timed with a timing gun and the timing wire disconnected. Change the plugs, wires, cap and rotor, PCV valve, air filter, fuel filter.
__________________
1995 Factory Blazer Service Manual for sale, PM if interested. |
||
05-21-2005, 09:14 PM | #5 | |
AF Enthusiast
Join Date: May 2005
Location: Snow Hill, North Carolina
Posts: 690
Thanks: 0
Thanked 1 Time in 1 Post
|
Re: Misfire?
A leaking injector could be allowing fuel to drip into the cylinder, and into the crankcase after shutdown (overnight).
Does the check engine light 'light up' when you turn the key to the 'start' position? If it doesn't, fix this FIRST!!! |
|
|
POST REPLY TO THIS THREAD |
|
|