Another ECM question

[rusty ol ranger]

86 bronco 2.

Ive been battleing a few annoying little running issues.

First, it was a surge when warm under light throttle and a hard cold start.

Could not get codes from ECM.

Changed ECM with the one from rusty #2 (not the one its currently running)

The surge went away completly and i can (kind of) reliably get codes now. It still is weird on a cold start. It cranks, putters, dies. Cranks, fires up great, dies. Third try it starts but is still a bit weird if you dont let it run for about 30 seconds before giving it pedal. Warm it runs beautifully.

Heres the issue...

When i do KOEO codes it goes perfectly, i keep getting code 31 and 84. Both EGR related.

Now...when i do KOER it starts doing the testing fine. It revs up, drops down, shows "6cyl" on the scanner.

It asks for the "goose" test (code 10), i do that, code 31 comes up, and then the scanner loses communication.

I left the scanner on for 10 minutes and it still read 31, no square blinking to indicate communication. I repeated this to a Tee 5 times.

This almost HAS to be a junk ECM right?

I opened it up didnt see anything obvious. But i would think if it was wiring id get nothing on either test.

input?

 

[bobbywalter]

the ms3 will just piss you off to learn and dial.....but getting this old shit running 100 is not really a thing without it. keeping these old beat to shit computer boards and drivers alive after 30 years is not a realistic expectation. just like a carb.

adapting a different 3.0 system is a potential....or the 4.0 to get you up to eec5. definitely a pia.

your at the mercy of pcm dice rolling staying within the eec4 wiring and electronics.

 

[rusty ol ranger]

the ms3 will just piss you off to learn and dial.....but getting this old shit running 100 is not really a thing without it. keeping these old beat to shit computer boards and drivers alive after 30 years is not a realistic expectation. just like a carb.

adapting a different 3.0 system is a potential....or the 4.0 to get you up to eec5. definitely a pia.

your at the mercy of pcm dice rolling staying within the eec4 wiring and electronics.

dont i gotta change a bunch of other shit to switch to that though?

 

[bobbywalter]

yes....or no.

and to run the edis will take a 36-1 wheel...

just depends on what you want.

me.....eco boost 4 whizzer. tdi vw.....or 5.3 ls would be the next step.

unless i could find 2 good running 4.0 engines for under 700 bux.

the bronco 2 and 4.0 were made for each other. especially with a manual trans.

 

[bobbywalter]

Stinger PIMP | MegaSquirt

 

[rusty ol ranger]

yes....or no.

and to run the edis will take a 36-1 wheel...

just depends on what you want.

me.....eco boost 4 whizzer. tdi vw.....or 5.3 ls would be the next step.

unless i could find 2 good running 4.0 engines for under 700 bux.

the bronco 2 and 4.0 were made for each other. especially with a manual trans.

I apperciate the input...but this 2.9 runs great besides this.

Plus you know me....ride or die with a 2.9 lol.

After you mentioned the megasquirt stuff i started reading some stuff about it and got a headache. Im just now starting to get my head around EEC IV. lol

 

[bobbywalter]

the stinger pimp is a pretty good deal if the wiring is spot on.

 

[4x4junkie]

I've been starting to think nowadays that a lot of these issues with malfunctioning PCMs (ECMs) might be because of the electrolytic (aluminum) capacitors failing (them drying out from age) with as old as they are. There's really not much else inside them that can go wrong (transistors, diodes, film-type resistors, ceramic & mylar caps, etc. are all not affected by age). There's only a few such caps in there, I'd say whenever you have a flaky PCM that doesn't want to spit out codes / acts weird-unexplained / whatever, try replacing all the caps with new (this is often referred to as "recapping" it). It's cheap, easy to do (if you're good with a soldering iron, anyway), and little will be lost but a few dollars and maybe half-hour of your time if that turns out not to fix it.

Good caps can be had from places like Mouser or Digikey, you just have to be sure to match up the ratings correctly (microfarad (µF) ratings have to be exact, voltage & temp ratings can be the same or higher). The caps in the PCM should be marked what their values are.

 

[bobbywalter]

actually....out here at least....they get covered in films and salt dust and have all sorts of issues burning a/d converters and drivers ect.

the diode sections for the o2 heater circuits ect get fried...but those are easy to fix.

most cardone units are recapped, and your right. for the most part all that is needed.

if you pull it apart and its clean...its worth jacking around with for damn sure.

 

[rusty ol ranger]

Ill open it back up but last time i looked in it it didnt look bad.

But IIRC my ranger had goofy issues running on this ECM too.

 

[bobbywalter]

Home - ECU Exchange

ECU Exchange specializes in the re-manufacturing and repair of engine control modules.

www.theecuexchange.com

i found it. send that dog to those guys.

i have a a9m i will be sending in as long as its under 150-170 to fix.

 

[rusty ol ranger]

Home - ECU Exchange

ECU Exchange specializes in the re-manufacturing and repair of engine control modules.

www.theecuexchange.com

i found it. send that dog to those guys.

i have a a9m i will be sending in as long as its under 150-170 to fix.

I never heard of them. Ill contact them

 

[Cees Klumper]

My '90 ECM has two capacitors. One day the truck refused to start and sure enough both capacitors were leaking. Replaced them with the correct values new capacitors and it was good again. It did not cost more than a few dollars and some spare time indeed, easy to get to and easy to do. Maybe just as a precaution worth doing, it was really one day to the next with no pre-warning in my case.