Checked the shaft bushings, they are good. I guess i'm puttin cap rotor plugs and wires on it next...

Any clue as to why it's idling on its own all of a sudden? Good to know the timing chains arent a problem on these though...

 

BTW, water out of the exhaust is normal for vehicles with catalytic converters. Short trips build up moisture in the exhaust system; it takes a good 20 miles of driving at normal operating temperature to "dry out" the exhaust system.

Autolite wires spec out better than AC Delco, at half the price! AC Delco only for the plugs, cap & rotor.

 

That explains why it's so much more than my '98... It gets driven daily...

I knew ACDelco only for plugs cap and rotor, but didn't know that about autolite wires... good info.

Will let everyone know how things turn out... once (if?) they do.

 

Replaced cap, rotor, plugs, and wires... Runs again. Odd thing though... reset the computer... ran it and let it come up to temperature... and it started idling on it's own. But then I turned it off and tried to start it again and now it wont idle again...

So I guess it's off to the shop tomorrow or Saturday...

 

A knowledgeable technician with a good scan tool, should be able to spot a problem by looking at streaming data and comparing it to what it should be. Looking at the misfire history file will tell what cylinders have been misfiring since the PCM was cleared last. See if you can get them to give you that information. There will be listings for each cylinder, and how many times it has misfired.

Just on a crazy hunch.... The plug wires connect to the cap horizontally, and the distributor housing, is it cast aluminum or plastic?

 

Not sure if the distributor is aluminum or plastic... I wanna say it's an aluminum one which from what I've read makes me think maybe it was replaced...


Took it to the shop Saturday... the guy put the scanner on it and couldn't spot anything out of the ordinary... His best guess was maybe the MAP Sensor or IAC intermitantly not working. Pretty thin, but...

Took it home and was playing around with it wondering if I would ever get it to run, and unhooked the battery to try to reset the thing one more time.
Went in and had lunch and forgot all about it. Came out the next morning and hooked the battery up and damn if the thing didn't start right up and idle... It's not perfect... when it's cold it almost wants to die if you turn the wheel hard or something to put a load on it... but it's been 3 days now and it still works... Haven't put any miles on it to speak of, just ~30 minutes of running in the driveway, but it does run...

I'm stumped as hell. Just hope it lasts I guess... really dont know what to think...


EDIT: It occurred to me as i typed this that the fact that the idles speed comes down alot under load could point to the IAC...

 

So Ive been driving the Blazer some. Have about 30 miles on it so far. It still idles fine, but has a new problem...

When it's warmed up, the ides goes to ~1500 rpm and I have a code P1509, which is IAC Error High Idle Circut RPM.

Did a search and 1509 is usually vacuum leaks, but I don't have any that I can find...

Is my IAC bad after all or ???

Really liking this truck so far... runs nice and is pretty damn quick. seems to do ok on fuel so far...

Look foward to your suggestions.

Thanks

 

Have you adjusted the throttle stop screw on the throttle body? If it's out of adjustment, you'll need a bi-directional scan tool to adjust it.

Here's a test for the IAC that you can try:

Turn the engine OFF.
Disconnect the IAC harness connector.
Measure the resistance across the IAC valve terminals "A" and "B", and also across terminals "C" and "D".

Resistance should be 40 to 80 ohms for each measurement.

 

It seems to be ok today... Go figure. Will check the resistance in the IAC.

I was not aware there was any kind of screw on the throttle on these... Please explain.

Thanks.

 

On the passenger side of the throttle body, there is a small adjustment screw, (Torx). It's set at the factory, (Loctite on the threads) to keep the idle speed just high enough to prevent stalling if the IAC happens to fail in the fully closed position. It's adjusted after commanding the IAC to the fully closed position with a bi-directional scan tool. Best not to mess with it