What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

TBI Motor Problems

B

bassin4507

Registered Member
Joined
Dec 22, 2003
Posts
23
Reaction score
0
Location
Westport, MA
MY 91' K2500 has been acting strange lately. It has no codes showing up, but sometimes when it idles it will idle from 500-1000 RPM for no reason, and it has a stumble when under load, it will clear out if you give it over 3/4 throttle. I checked my cap, rotor, plugs, wires, changed fuel filters and an air filter. I installed a fuel pressure gauge and the fuel pressure stays constant when it stumbles.
 
check for vacuum leak. i'm chasing down a similar problem. i;ll let you know if i find anything. i hopw you'll do the same. /forums/images/graemlins/burb.gif
 
What is the best way to check for vacuum leaks besides, just looking at the hoses for cracks, holes, cuts, etc. ?
 
yea, check your hoses and vacuum lines. another thing i'm doing tomorrow is spraying carb cleaner around the base of the tbi. its supposed to either change idle characteristics or bubble. i'm not sure, but i figure i'll know when it happens. other things to check are the egr diaphram and cruise control diaphram sticking. check throttle linkage, tps sensor. see if your computer is throwing a code too.
 
I am having a simular problem with mine. When yours is under load and stumble what sounds does it make? Mine sound almost like a backfire. I also have no codes, so I am thinking about changing out the distributor and checking the timing chain. Not sure where else to look for the cause of this problem.
 
Mine mdid kinda the same thing. Mostly it did it in th mornings backing out of the driveway. It would load up and act like it wanted to kill it self. Wound up being the EGR valve. It would be easy to test just unplug the vac line that goes to the egr and plug the line and see if it still does it. /forums/images/graemlins/deal.gif
 
I don't notice any different sounds when it stumbles, the motor is only 1 year and a few months old, all the sensors are the same age except the EGR is about 2 months old. I'll have to check my distributor.
 
I checked for vacuum leaks, and there were none. Next I pulled my plugs again and noticed that the gap on all of them was bigger than .035 so I re-gapped my plugs down to .035, and ran some Sea-foam through the motor, and the problem has completey gone away.
 
Glad to here ya got it running good.

[ QUOTE ]
I re-gapped my plugs down to .035, and ran some Sea-foam through the motor, and the problem has completey gone away.

[/ QUOTE ]

What is sea-foam? I /forums/images/graemlins/dunno.gif
 
It works real good as far as I can tell. You can either buy it in and spray can, or a regular can. The directions say you can put it in just about anything from small motors to big. I just sprayed some into my throttle body while it was running. On my 78 K20 I disconnected the brake booster vacuum line and poured some in there while the motor was running. Then I shut it off for about 5 minutes and it smoked quite alot (it's supposed to) and ran better afterward.
 
You must log in or register to reply here.

Latest Posts

Top Bottom