90 Blazer Idle problem

[opfor2]

90 Blazer Idle problem ***UPDATED***

****Update****



After spending countless sleepless nights trying to figure out why my 90 K-5 Blazer had this slight idle problem when I would come to a light or sitting in traffic. I discovered that the fuel cone coming out of the two injectors appeared to be somewhat weak at idle. I decided to rebuild the TBI unit and I took a trip down to my local NAPA parts dealer and purchases there Echlin 2-1752 TBI tune up kit for $ 35.00. Included in the kit are all parts, gaskets, o-rings, and FUEL INJECTOR Filters necessary to rebuild the TBI. The rebuild is very easy and straight forward, just follow the included instruction sheet and you shouldn’t have any problems. After replacing all parts, gaskets, o-rings, and fuel filter my K-5 now run’s great. It purrs like a kitten. I’m thinking that the two fuel filters on the TBI injectors were dirty and by replacing them with new ones solved the problem. I’m sure that replacing all of the gaskets and o-rings also helped. I hope that this information my help someone else with a similar problem.



Dan…




Hi all,

My 90 Blazer has a small idle problem. When the engine is at operating temperature and I’m stopped at a traffic light I notice a small variation in the eng idle. The idle will fluctuate up and down slightly. This problem just started a few weeks ago. I’ve checked all of my vacuum hoses and TBI gaskets. Could the idle control valve have something to do with this ? If so, shouldn’t I get a code on the ECM ?

Thanks

Dan…

 

[Thunder]

Might check the throttle body base gasket. They go bad all the time and cause vacuum leak/idle problems.

 

[lifethroughdeath]

If you do a search, this has been covered a million times, as it is a really common problem for us TBI guys. Most people just end up throwing it in neutral at lights. /forums/images/graemlins/dunno.gif

 

[opfor2]

[ QUOTE ]
If you do a search, this has been covered a million times, as it is a really common problem for us TBI guys. Most people just end up throwing it in neutral at lights. /forums/images/graemlins/dunno.gif

[/ QUOTE ]

The funny thing is that I did do a search and I didn't find anything. Maybe you could be so kind and direct me to one or two threads that contain the info that I need.

Thanks

Dan..

 

[Thunder]

You might try pulling off and cleaning the IAC and EGR valves. They can get carboned up and stick.

 

[lifethroughdeath]

[ QUOTE ]
The funny thing is that I did do a search and I didn't find anything. Maybe you could be so kind and direct me to one or two threads that contain the info that I need.

[/ QUOTE ]

Here Are A Few For You To Look At

 

[opfor2]

Thanks for your help. One more ?. What's a good cleaner to clean an IAC ? Would carb cleaner work or is there something that works better ?

Opfor.

 

[tx_sub]

some say carb cleaner will corrode the iac parts. fuel injector cleaner is supposed to be better. i'ma use one or the other and an old toothbrush on mine.

 

[elacruze]

A dirty throttle plate/body will do this. I don't know why. Clean up the plate and area around it's closure with carb or injector cleaner, and see if that helps. Spray the joints behind the throttle body to check for leaks.
I just learned that some throttle plates are clearcoated, and some carb cleaners strip this coating off...I don't know what the consequenses of that are.

 

[opfor2]

[ QUOTE ]
A dirty throttle plate/body will do this. I don't know why. Clean up the plate and area around it's closure with carb or injector cleaner, and see if that helps. Spray the joints behind the throttle body to check for leaks.
I just learned that some throttle plates are clearcoated, and some carb cleaners strip this coating off...I don't know what the consequenses of that are.

[/ QUOTE ]

I've already cleaned the throttle body and plates with carb cleaner and "Sea Foam" cleaner but it still didn't help. I also removed and cleaned the IAC and it does seem a little better but the idle at a light and in gear still isn't smooth.

 

[opfor2]

bump..