96 Blazer Intermittent Start and Stall

[delfire66]

Hi , I'm a new member here. I've gone to this form for clients of mine on numerous occasions and have found great answers. Thanks for that. Now I have Problem. Let me tell you about my 96 2dr. Blazer with 121,000 on it . It will randomly not start. Come back next day starts and runs fine. It will randomly Stall (usually at lower RPM) it may start back up or not .If it dosen't start, it will start up 2 hours later, like nothing happened. Fuel press. reads 58-62 lbs. running or with k.o.e.o., Even when it won't start. It holds press. for 2 min. c.e.l. never comes on when car won't start. c.e.l. would come on at close to red line and would be "left bank rich" Dont think it's crank or cam sensor cause their are no codes? Gonna check coil and ICM .
Checked for bad connectors at ecu, and everywhere, pulled, giggled on harness at ign. switch,plugs on drivers side under hood.Pump coming on even when car doesn't start. When it dies or doesn't start it doesn't sputter, like it's not getting gas ,I think it's voltage. I don't know, I'm going crazy!!
Car has new fuel pump and spider installed 2 years ago, run 44K every 6mos. Car is perfect inside and out Very well maintained . I want to keep this car forever, I love it. Thank You! Greg

[jamesslcx]

Greg, have you tried squirting a little fuel or carb cleaner into the throttle when it won't start, also did you check for fire when this occurs?

[delfire66]

Thank You jamesslcx for responding. It has 60 lbs. of fuel pressure when it's not starting. I tested the ICM and it seems to be working. going to check for actual spark as well Thanks, Greg

[jamesslcx]

Greg you are welcome, let me know if I can help.

[Gabe25]

Greg,

1st. of all, Welcome to AF.

I had the same trouble that you are having with my 96 Blazer. I ended up test my Ignition Switch and found that it was the cause of my problem. $80 later. Runs like a Champ.
Here's is a link on replacing the switch: http://www.automotiveforums.com/vbul...gnition+switch

Here's a link for the Switch: http://www.rockauto.com/catalog/moreinfo.php?pk=446115

Let us know if you need more help.

[delfire66]

Originally Posted by Gabe25

Greg,

1st. of all, Welcome to AF.

I had the same trouble that you are having with my 96 Blazer. I ended up test my Ignition Switch and found that it was the cause of my problem. $80 later. Runs like a Champ.
Here's is a link on replacing the switch: http://www.automotiveforums.com/vbul...gnition+switch

Here's a link for the Switch: http://www.rockauto.com/catalog/moreinfo.php?pk=446115

Let us know if you need more help.

Thanks! I wish It was that ! Took column apart and wiggled and giggled and yanked, could not duplicate problem. When it does happen I'm getting 12 volts at coil though. So that rules out Ign. Switch? The weird thing is no CEL on ever. Thanks Greg.

[Gabe25]

Originally Posted by delfire66

Thanks! I wish It was that ! Took column apart and wiggled and giggled and yanked, could not duplicate problem. When it does happen I'm getting 12 volts at coil though. So that rules out Ign. Switch? The weird thing is no CEL on ever. Thanks Greg.

Greg, Wiggling, giggling and yanking isn't going to tell you that the switch is good. Inside the little Black Box (Ignition Switch) there are make and break contact springs that control your whole electrical system for your car. All it takes is a little carbon deposit on any one of the contacts and you can have trouble. This type of trouble is a know fact for the Blazers. You'll need to test the switch by checking the voltage output of all the leads, or the next time you have trouble. Take a look at your instrument panel and see if everything is reading. I noticed that I lost my oil pressure reading when it wouldn't start. Sometime my fuel pump would work, or even lost my running lights.

[delfire66]

Fixed!! CKP Sensor was the problem. I lightly tap with mini dead blow CKP when engine was running and car would almost stall wiggled CKP and car died. CKP had deteriorated housing. Put new one in starts fine and no problems now. BUT old sensor had pretty good size groove in it. Is sensor sopposed to tough wheel? I don't think so. I put the two shims on just to be sure. Is this rite?? Also no codes or light on ever. Thanks Greg

[jamesslcx]

Delfire thanks for sharing the lesson of the day.