Hi folks.
Bit of background info here. Had my Blazer for about a month and have experienced a host of issues. My first was a no-start - bad ICM. Second no start last week - my fuel pump went out. Prior to the pump going out I had a cylinder 2 misfire code while going uphill. Seems that around 50+ mph and going uphill the Blazer experiences a lack of power and its like the trans doesn't want to shift. After getting the fuel pump and plugs replaced I figured this would sort out the problem.

I was driving away from the shop yesterday and everything seemed fine. I hopped on the Interstate to go home when I experienced a kind of forward/back almost rocking motion around 60mph while going up a slight incline at 2500 rpm (ish). At that point a check light came on. I experienced the same bumpiness once or twice more before getting home. The code turned out to be a mass air flow sensor issue. The light went out on its own before I had a chance to investigate. Later that day I took the MAF out and cleaned it (using the BlazerForum how to -thanks!). I drove around a little and it "seemed" to be a smoother ride. Unfortunately I hopped on the Interstate once more and experienced the rock back and forth motion (imagine an inexperienced driver with a stick shift) this time at about 50mph and 2000rpm. The CEL light came on once more but disappeared earlier today. In fact it disappeared right as I was turning onto a side street, at which point it appeared that I lost all drive! It was like the car had kicked itself into N. I put her into park... then cycled back to drive but no dice. One more attempt and she started moving again. Very weird.

I'm looking for things that I should be checking out here. Oh, I should add that around 4000rpm you can hear what sounds like a tick tick rattle coming from somewhere in the front.

If anyone has any ideas on what's up with this blazer, I would like to hear it. I've heard some ideas relating to the EGR valve but have no idea where it is (diagrams?) . After today's loss of drive, I'm concerned about my tranny.

Thanks everyone!

 

Sounds like it's possessed...

The EGR valve is located between the alternator and the A/C compressor (search will turn up pictures). It is about the size of a soda can.

A failing ignition switch can cause all sorts of odd problems. Being a 98, you should have a security light that illuminates on initial startup then goes out after a few seconds. If this comes on while driving down the road or has come on in the past while driving, this is a good sign that the ignition switch is going bad. Another member just sent me an ignition switch that I was planning on dissecting and writing up a "how it works and what goes wrong" type post when I get some free time (yeah right..).

Anyway, was the code the same the second time around? For the MAF sensor?

 

Possessed... yes that is one word for it!

Didn't get a chance to check the code before the light went out. But it stores these right, so I should be able to still retrieve the information?

I've not seen the security light come on while driving. I did have the little airbag man pop up after hitting a pothole but that's another story.

So do you think it's worth pulling the EGR? Also, thoughts on losing drive?

 

If you are losing power to various systems (like an ignition switch may do), then it is possible that the transmission lost power, resulting in the no drive condition.

And yes, the PCM does store the codes. You should be able to retrieve them.

 

So I checked out the codes on my Blazer today. The two codes I've pulled are:

P0102 - MAF Low voltage to circuit
P0404 - Exhaust Gas Recirculation Control Circuit Range/Performance

I've cleaned the MAF as described on this forum. I removed the EGR, cleaned as much gunk out of it as possible and replaced the gasket.

Now just getting P0404 and the Blazer is hopping like it's on hydraulics LOL. Any ideas?

 

Bad EGR valve? Were you able to clean the pintle area of the EGR valve?

 

Cleaning it was difficult. Maybe I didn't clean it enough? I can get a new Delphi EGR for $50 on ebay so I'm leaning toward that. I might attempt a second cleaning first though.

 

Second cleaning didn't help. I ordered that valve from ebay so it should get here in a day or two. Just to be sure, what torque should the EGR bolts be set to?

 

Bump...

Any ideas on the torque setting?

Also, anyone else that has had this problem.. if the new EGR doesn't cure it.. where to next?

 

25Nm or ~20ftlbs. It has been posted before and should be in any good reference manual...

Have you tested the EGR valve? It does require a Tech2 or equivalent full feature scan tool, but it could save you some $$$.