92 4.3L vortec error code question!

Hi,

I have a 92 Blazer with a 4.3 L vortec. I just replaced the intake manifold gasket on it over the weekend. Once i was done the blazer started right up with no hesitation. Test drove it, realized the timing was off, so i adjusted the timing, and got it pretty close and seems to run real well. I couldn't find the timing connecter, that i have read needs to be disconnected, but i marked the distributer before i removed it.

Question 1. I know the timing connecter is supposed to be between the firewall and dist. but i couldn't find it. Any assistance on locating it?


The real problem is that the day after i got everything set and put back together, I had the blazer out for a 10 mile drive or so, and then when i went to start it up, it would run for a few seconds and then died. Start up again and then die a few seconds later... I got the error code 34, which is a MAF error code. Does the Vortec have a MAF? is it in the front of the intake? when a MAF is mentioned i think of a LT1 style MAF or something of those sorts. Soooo, i went back a day later after it wouldn't start and it started right up, cleared the ECM, and no problems yet, but its only been a day. Anyone have any ideas? a freak thing?

Thanks in advance for any help,
Nathyn

In my 1988 Blazer with a 2.8 the wire which needs to be disconected while setting base timing is a yellow wire I have found if you peal back the carpeting where the passengers feet go. It is a yellow wire coming from the ECM to the distributor and clipped together with a plastic clip for the sole purpose of unclipping it to set base timing. As for the MAf sensor, I'm not that familiar with that code. You may want to clear out the ECM by unplugging the negitive on the battery and trying to restart the engine. Make sure the distributor is torqued down all they way and didnt move way out of timing while you were driving it, check for vaccum leaks as well.

Thanks i'll have to check for the wire under the carpet...

I checked the distributer, and i am sure that it hasn't moved. I did clear the code before i drove it last, and probably have put another 20 miles on or so and haven't had the problem show up again yet. Aside from the instance the car has driven excellent, so i wouldn't guess a vacuum leak, but i guess you can't rule it out...

Supposedly the Code 34, mean no MAF reading for 4 seconds or something while engine was running??? Hopefully someone can chime in and shed some light on this problem


Thanks,
Nathyn

As a last resort there always is the chevy dealership down the street... good luck though!!

haha i am too stuborn to go to the dealer...its like admitting defeat...and having to pay for it is like throwing salt on a wound..


anyone have any idea about this code 34?


Thanks,
Nathyn

haha i am too stuborn to go to the dealer...its like admitting defeat...and having to pay for it is like throwing salt on a wound..


anyone have any idea about this code 34?


Thanks,
Nathyn

Code 34 is for the MAP sensor, not the MAF, the MAP.

The timing wire is the beige and brown single wire connected to the PCM under the glove compartment and has to be removed to time the vehicle to base zero.

Disconnect the timing wire.
Time the engine to zero with a timing gun.
reconnect wire.
reset computer

DRIVE!

Do you have a TBI or CPI engine?

When adjusting your timing, I hear it is a good thing to have the truck's engine warmed up completely to operating temperature. Forgot where I picked that bit of info up, but found it curiously lacking whenever someone says to adjust base timing. ;)

When adjusting your timing, I hear it is a good thing to have the truck's engine warmed up completely to operating temperature. Forgot where I picked that bit of info up, but found it curiously lacking whenever someone says to adjust base timing. ;)

You know what, I never thought of that.

Hmmm.. We should look more into this.

Anyone care to google for info before we set this into stone?

I too have always heard that it is best to set timing when the engine is warmed up and thats what i have always done as well.

My problem was that i just couldn't find that darn wire, i thought it was supposed to be in the engine bay, and couldn't find it, so i made due with the little adjustments.


MAP, alright that sounds better, the internet page i found said MAF for some reason. Where is the MAP sensor? The sensor in the air duct coming into the intake is the MAT (manifold Air Temp) sensor right? So if i was to guess, the MAP sensor is one of those sensors right around the front of the intake? anyone shop manual diagram illustrating the location by chance? I wonder why the engine throw that code...maybe the plug was loose? any ideas?

Its a vortec, NOT throttle body injection, so i guess thats the CPI (not sure what the CPI stands for (C....port injection)

Thanks again for the help!
Nathyn

Did you read my timing wire post above?

Yup i read that you said to look for it under passenger side dash. Sorry my last post was a little misleading, i meant that before i started this post i couldn't find the wire. Thanks for your help...

I did some searching, and found that the MAP sensor may be due to some EGR problems....i'll have to do some more investigating...




Thanks,
Nathyn

Remove it, clean it, and reinstall the EGR valve with a new gasket.

The ecm automatically advances & controls timing
according to timing tables when the wire is hooked up.
If you try turning back the timing to 0*tdc with the
wire hooked up your accually retarding the base timing.

The ecm automatically advances & controls timing
according to timing tables when the wire is hooked up.
If you try turning back the timing to 0*tdc with the
wire hooked up your accually retarding the base timing.

True, that timing wire is actually the timing advance wire for the PCM.

It needs to be unattached or you won't be setting the proper timing.

You can check out my experience here:

http://www.s10forum.com/forum/showthread.php?t=113559&highlight=cpi+replacement

Detialed instruction and photos can be found in this thread here You will have to register, but it is well worth it:

http://www.s-seriesforum.com/forum/showthread.php?s=&threadid=34668

lol i was just finding my pic.
its here. http://www.s10forum.com/gallery/view_album.php?set_albumName=album2091

Go and register at s-series forum.

Nice pic!

Will keep this bookmarked for future threads.