89` Blazer Stalling

I had problems with my RX-7 and hills till i replaced my filter, then the engine just died, possibly, is the route hillly on your way home?

EGR valve possibly, or EGR solenoid not closing the valve after you get off the highway. The EGR valve only opens at highway speeds, when TPS input is constant. So, during your final 55 mph run the ECM is opening the EGR valve to lower NOx emissions, and as you get off the highway and come to a stop, it close the valve. If the valve is old and cruddy the pintle could be sticking and hanging open, or the solenoid might not be doing it's job either.

This causes a lean condition and will have her running like ass till the pintle closes. If it were the fuel filter you'd be having problems at 55 mph as that's where the engine is sucking the gas, not at the end of the off ramp when it's hardly using and gas at all.

Next time it happens, kill the ignition and turn her off. Let sit for maybe

Doc

Hey Doc, That makes sense about the filter. I just change it today for hell of it. It was a learning experience for my 18-year son so not all was lost.

I checked the codes today. Yesterday was the first time I saw a Check Engine light. It came up with a code 34. Does that match your feelings?

I really appreciate your words of wisdom Doc.

JQP

Doesn't match my initial guess at all. Code 34 is MAP sensor, low voltage. Usually when a MAP sensor or the MAP vacuum line is shot it misbehaves all the time, not intermittantly like yours.

You need to check a few things, such as the electrical connections to the MAP sensor (clean em' up real good), the vacuum line to the MAP sensor (OE line is a hard plastic that gets brittle over time, could be it's cracked). Replace the line if it's shot.

If it still misbehaves after that, disconnect and plug the vacuum line that leads from the TB to the EGR solenoid and see if that helps at all. SES light will come on and set a code 32 when you do this as the ECM is trying to open the EGR valve and it can't. Just ignore the SES light and see if it's still being difficult.

Before you do anything you want to reset the ECM (just yank either of the battery cables for at least two minutes) so if she spits future codes you'll know that it's "new" and not just the stored one.

Doc

I like pulling the ECM fuseS (there's two). That way I don't have to reset the clock etc....

~KJ/TLGM