Running Warm, Check Engine Light, Hiccupping

[jeremyjudd]

Afternoon all -

I've got a '94 Ranger with the 4.0 ltr.

A week ago the check engine light came on while I was rolling down the road. I noticed the engine also begin running warmer and hiccuping while I was driving.

The KOEO test indicates a 327 and 332 error (KOER test popped the same, but no others).

I tested the connection to the EGR valve and pressure sensor, they are within specs. (The pressure sensor is only about two years old).

So I replaced the EGR valve and cleaned out the ports on the upper intake manifold - no improvement.

Tested IAC - within specs and engine dies when unplugged.

I replaced the vacuum lines to the EGR valve as it was crushed in one place - no improvement.

The engine coolant temperature sensor has 2 steady volts going to it, my manual indicates 5 volts. Could this be the problem?

Additionally, my ABS light popped on a few weeks ago. Brakes are working fine and I had to replace the RABS unit about two years ago so I doubt it has any issues.

I'm wondering if an ABS light and these error codes are indicating that the PCM is fried?

Anyone know of a way to test it?

Thanks.

 

[cr_the_machinist]

I'd try replacing that coolant sensor first. I think they are only like a $25 part tops new. I'd install it, unplug the battery for a little bit, and see if the pcm will like the new sensor.

It's odd the your pcm would give off 327 & 332 trouble codes because as far as I know the relates to a knock sensor, which the 4.0 ohv does not have?

What do you mean running warmer? Are you keeping an eye on your coolant levels?

Sometimes those larger auto parts chains will have a tester but they'll probably give you the run around, like most of those corporate stores do. Most every dealership can test the pcm as well but you probably know how they are too. If I was in your position, I'd call the dealership and see if I could just bring in the pcm to get tested. They may be able to reflash the pcm as well if it just had a conniption. Good luck!

 

[Big Jim M]

Hiccupping without backfiring is most likely fuel related. Running WARM is prolly normal..
Big JIm

 

[jeremyjudd]

The fix is in!

Alright - first things first.

327 and 332 are both related to the EGR.

327 (O,R,M) EGR feedback signal is/was low - EVR or PFE

332 (R,M) EGR did not open/respond during test or if memory code, did not open intermittantly - EVR or PFE

There is a list of codes and there info on this site that can be found here:
http://www.therangerstation.com/tech_library/3digitcodes.html


Second, I'm a Ranger nut, I would NEVER let my coolant get low.

I just wouldn't do that to my baby.

I learned with this problem that you CANNOT test a PCM at any auto parts store. It just isn't one of the parts they test for whatever reason.

Running warm in this pickup is not normal. Last time the needle reached a tiny bit past the halfway mark my radiator exploded (I hate you Nevada mountains and my brother in law for telling me it was a "short cut" while I was pulling a u-haul trailer loaded to the gills).

So - here's what happened. I replaced the EGR valve with no luck, then did some extensive testing on the DPFE. There is a comprehensive guide to DPFE testing (who had time to put this together I do not know) here: http://www.ford-trucks.com/forums/342419-how-to-test-your-dpfe-sensor.html

The DPFE wasn't working properly. Replaced it, runs like a champ and the temperature is back where it should be.

FYI - I replaced the DPFE about two years ago with an aftermarket part. Having to replace it again would have made it worth the extra $$ to buy it from Ford the first time around....


Thanks for your help.

 

[AllanD]

Hiccupping without backfiring is most likely fuel related. Running WARM is prolly normal..
Big JIm

Hiccupping with or without backfiring is usually fuel related and any time you suspect a fuel problem replace the filter before you even think about anything else.

As for an ABS problem throwing a light and an engine problem causeing a CEL?

Could it be "computer related"? Absolutely it could, but if so it's TWO seperate computers as the Engine PCM and the ABS control unit are completely selerate entities.

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