Last 3 days in the morning i crank the blazer and it sounds like it has a large cam,and if i immediately put it into drive it shudders and stalls.But!! if i crank it and rev it up and down from 3000rpm or so for 10 or so seconds it idles perfectly fine then! It did this off and on for a while then my coil went out and i was stuck on the side of the road back in may. Or maybe that was a coincidence when that happened..Has a new fuel pump,new ngk v-power plugs(idled like this before plugs,so it cant be plugs or wires)...Im wondering if it might be the distributor cap since i didnt replace that and the little prong things inside the cap looks a little corroded? Its not popping codes.thanks


here is a vid i made of the trucks bad idle,didn't realize i had 18 secs left worth of video.pfft.

http://www.youtube.com/watch?v=ftKv_RDXCXI

 

How is the spray out of the injectors? Have you removed and cleaned the IAC valve on the throttle body? Have you checked the throttle body base gasket?

 

spray looks fine.i do run a bottle of cleaner in it once a month or so.the idle control valve? i cleaned that with some cleaner a while back and it idles fine after it warms up..i have not looked at the gasket yet.

 

i made and added a video of the rough idle..hopefully someone might know..

 

i dunno i dont really trust the NGK plugs. i wouldnt have used them. another thing to check and this happened on my was the idle control valve was very loose so i changed it out completely (not that it needed it but i did it anyway) and it solved my issue.

 

ive been using the plugs since may and i haven't had a problem,i do really like them..and it did have the idle issues before the plugs then it randomly stopped for a while,now its doing it again.

 

I have used NGK plugs in these engines without issues. I believe there was one particular s-series factory which installed NGK double platinums as standard.

Go over all of the vacuum lines and gasket interfaces with an unlit propane torch and see if you can find any leaks. The sound of the engine will change.

If that does not turn up any results... How is your coolant temp on initial startup when cold? Does the temp gauge read properly?

 

i really don't think it ever did read right..it sits on the bottom (100) at start and when warmed up its around 140 mark.i did put it a 180 thermostat in it but i do have a mechanical temp gauge im wanting to put in it to check it,as well as a oil gauge.and i checked for vaccum leaks with starter fluid today and didnt find any..i took the iacs(is that right?) apart and cleaned it up,didnt help.

what i dont get is when i crank it,if i rev it up and hold it for 10-15 secs it skips and runs bad then all of a sudden runs perfect.Can a distributor cap be the problem? when i did the plugs and wires i didnt buy a cap or anything dis. related because they didnt have one in stock at the time..and i noticed there is a little play in the cap(wobbles a lil)...and why is my font bold? when the bold isnt checked? pshh

 

If the gauge starts out already partially warmed up, this could be telling the ECU that the engine has some heat into it and that it does not need to be in the cold start fuel enrichment mode for it to run and warm up properly. Holding it for 10-15 seconds to get it to run better sort of makes sense if this is the problem. The elevated RPMs will put heat into the motor faster.

If you have not changed the cap and rotor, I would definitely recommend doing that. Make sure that you get a high quality replacement. Typically, the better caps come with brass terminals inside.

 

would you classify accel as a high quality replacement?