Just before spring break, I replaced the rotor, cap, plugs, and wires on my '92 EB 5.0. It just turned over 123.000 miles today. However, that freakin "check engine" idiot light comes on now - if cold, it's after a couple minutes' driving, if warm it will come on within 30 seconds. I'm stumped...What could this be? What could I have possible changed? (I haven't gotten around to getting some wire and pulling codes yet). It idles smoother, responds quicker, and from what I can tell (haven't put enough miles on it to tell yet), gas mileage doesn't seem to be adversely affected. Any ideas?

 

My 92 302 does the same exact thing, too bad i don't know what it is though...

 

The check engine light only comes on when there is an emissions related malfunction. It should have nothing to do with you replacing the cap, plugs, and wires. Might be just a coincidence. Your engine can and might run/perform exactly the same before and after this problem. Your self diagnostics system in your bronco's computer is just letting you know that there is an emissions problem. When you pull the codes it will let you know what area to look at. You might even have a few codes that have been there for a while but if its not emissions related it will not turn on the Enigine light.

Let us know what codes you get when you scan it.

Harlow

 

Are you still using the original O2 sensors ? That would be my bet then.






Mike

 

You NEED to pull the dam codes and stop trying to guess at the problem. Gp get the codes and post what numbers come up. Go through both the KOEO and KOER tests. If you search here you will find several posts with step by step instructions, or you could spring for the $35 bucks or so and buy one of these. It will perform both tests and also display CM codes....and will clear the codes as well as turn off the CEL.

Oh and if you can also spring for the extension cable it makes the KOER test more easy.

http://www.etoolcart.com/index.asp?P...OD&ProdID=3758

 

Hey Street, I got the same reader and can't get it to work on my '92, do you think the plug under the hood could be shot? Thanks...Al

 

Al......will the reader work on any other Fords within the year range it lists?
I have had mine for like two years now and I love it.....no problems at all.....works perfectly, is very easy to use, and the booklet that came with it is just outstanding as far as general info, codes, and all types of crap!

 

I haven't tried it on any other vehicles, although that's a good idea. It's a little wierd living here in Philly, believe it or not none of my friends drive and the few that do don't have anything it will work on. I'll have to go back over the manual and hope the weather breaks, pain in the **** not having anywhere to work inside.Thanks for the idea Street...Al

 

Oh for cryin' out loud folks... why are we doing things the hard way still? We are talking about a 92 model here... get the Haynes manual, buy a bag of paper clips, borrow ONE from the bag and pull the silly codes. If you can COUNT you can pull the codes withOUT ANY fancy devices of any kind. Its just that simple. A "Check Engine" light IS INDEED indicative of an EEC-detected fault in the ignition, emissions, and/or transmission (E4OD primarily). Pull codes and proceed from there. If you need details about how to interpret the codes post 'em.. we can answer those questions and get the truck back up and running right.

Sorry about the rant but its all very trivial in the face of something that Ford made so very simple to deal with.

 

Previously I would use a paper clip, and I guess in a emergency I would still use one, but I have got to say it sure is nice to just plug and play.......and it only cost a few bucks for the reader.....so what the hell, plus I am a big fan of gadgets!

 

Thats right, thanks for the correction. I've only had emissions problems thus far, [Knocks on Wood]. And Hopefully it stays that way. LOL

Your right though, Streetgang, that 35$ scanner is one of the best tools in my tool box.

Harlow

 

Calm down there, guys. All I wanted was to get pointed in the right direction before I pulled the codes, which y'all have done. Thanks for the input, I'll probably get up my courage and pull the codes this weekend (me and computers are not a good match...I miss the carburetor days).

 

That computer should be your best friend, it will tell you exactly what is troubling it. As for needing to be pointed in the right direction, just remember anything having to do with the engine or tranny, you allways check for codes first. Even if the CEL is not on, there may still be codes present. After retrieving the codes you can troubleshoot using a Haynes or Chilton's manual.

 

Alright, I got the codes. It's just emissions stuff, nothing important:

33 = EGR valve opening not detected
327 = EVP or DPFE circuit below minumum voltage
328 = EGR closed voltage lower than expected
332 = Insufficient EGR flow detected

So all together, what's this telling me, besides the fact that I should go back to pre-smog cars ? Obviously the EGR is faulty...I checked the connections I knew about, but I'm not really sure where to go with it from here...

 

Ok, only one problem I can see here before getting into the codes themselves. EEC computers either return two-digit OR three-digit codes... not both. So, somewhere a digit is missing.

As for the rest of the codes, disregard the DPFE reference. Your truck has an EVP sensor not a PFE sensor. They were used interchangably to perform the same fucntion on different model Ford's. The EVP sensor should be sending 0.5 volts back to pin 27 of the ECA when the EGR valve is fully closed. When the EGR valve is wide open the voltage should rise to just under 4.8 volts. Any reading above or below this during normal operation will trigger codes 327 or 334 respectively.

Code 328 is triggered when the ECA believes the EGR valve is fully closed and the voltage coming from the EVP sensor is too low. (Under 0.5 volts)

Code 332 is triggered when the EVP sensor indicates a voltage higher than parameters was sent from the EVP sensor to the ECA.

These codes may seem redundant but they have slightly different meanings depending upon whether they were received during the KOEO or the KOER test. Either way there are a few things you can do to begin with. First, remove and clean the EGR valve carefully or replace it. Second, check the electrical connection to the EVP sensor atop the EGR valve. Remove the EVP sensor from the EGR valve (three screws) and clean the foam filter under it. Make certain you install the EVP sensor with the connector "clocked" as it was before removal. Replacing the EVP sensor may even be a good idea. Once this is done, disconnect the battery for about 10 minutes to clear the ECA's memory. Reconnect the battery and go for a drive. See what you get.