410 and/or 422 Cam idle behavior

[WilliamWallaceGS]

Yeah man, pretty much. MAF sensor, IAT and ECM are old. Like you said though, with ECM I would think it would mess it up all of the time, not just idle. I did swap my granatelli for my old oem motorcraft MAF sensor, but both are pretty old with quite a few miles on them, and I cleaned them both with no positive results.

Sme good news though, I did just drive a few miles with the MAF unplugged, and it drove great. Idle was smooth, and didn't bounce around as much as it did with it hooked up, kinda like how it drove last night when I thought it was all good. Looks like MAF sensor it is. I really hope this is the end of this, so I can close this thread with accurate idle characteristics/data with the 410 for anyone else who was wondering.

 

[WilliamWallaceGS]

Yet another update:

Swung by and got a MAF today (a remanufactured A-1 Cardon at Advance, all they had in stock). Disconnected the battery for a while, installed the MAF, then hung around for a little while longer. Reconnected the battery and fired it up. Let it idle for 15 minutes or so and took it for a drive. It drove great, idle was good, power was there, accelerated smooth, all was well. I drove it for about 15-20 minutes without it skipping a beat, then stopped near my house and cut it off to see if it would still be good after I shut it down. About 5 seconds later, I cut it back on to drive home, and it was rough again, dang it.

I'm about to drive this thing off of a cliff. The fact that it drives smooth initially after battery reset, and then when the MAF is disconnected, tells me that mechanically the thing is sound since it is capable of being smooth, but something is not getting correct signals. PCM? I have no idea at this point, I don't even know how to test one of those. My inspection is due, so I may just have my mechanic take a look and see what he thinks, hate to admit defeat, but I'm out of ideas.

 

[jd4242]

Try a junk yard pcm.be real cheap on half price day at pick and pull.

 

[malohnes]

Does it perform differently when cold to when warmed up? Also, what about the IAT sensor? Have you ruled out faulty connectors or bad wires? Seems like the sort of quirky behavior a flakey wire or connector could cause.

This is the kind of stuff I usually have to figure out with my truck...weird things nobody else sees!?!

 

[WilliamWallaceGS]

Does it perform differently when cold to when warmed up? Also, what about the IAT sensor? Have you ruled out faulty connectors or bad wires? Seems like the sort of quirky behavior a flakey wire or connector could cause.

This is the kind of stuff I usually have to figure out with my truck...weird things nobody else sees!?!

It's a bit worse after it's warmed up, but even this morning when I first started it to come to work, it was a bit shaky. Then after driving about 1/2 mile to a stop sign, it was rough like usual and the truck had not gotten to temp. yet. I've checked my IAT sensor resistance when hot and cold, and they're both in spec according to my Haynes book. I made sure the sensing element is clean too. At this point, I'll take another look at it.

I'm going to take a look at my wiring harness and all this weekend, especially near the PCM/ICM/MAF and all and see if I see anything. I may pull my PCM and look for anything abnormal too just incase.

 

[malohnes]

What about the IAC? Wondering of it is functioning correctly...I had troubles with mine a while back and gave it a cleaning that I did not expect to do anything and it cleaned up the idle a bunch. Saved me some dough too.

Sorry this is such a pain to resolve, but you'll be a happy camper once you figure it out!

 

[WilliamWallaceGS]

I'm pretty sure I found the smoking gun...no, I really mean it this time. I pulled my PCM and popped the cover off to inspect the board. One of the capacitors leaked, and only had one wire connecting it the the board (should have two). The one was broken/eaten through and wasn't making connection. This has GOT to be it.

I've looked into this a bit, and seems as a lot of people just get an equivalent capacitor from radio shack and replace it (or all of them since I've already got the stuff out). I think I'm gonna give this a shot, if I break it then I'll only be out a couple of bucks on top of a rebuilt/new unit. Hopefully I can get it done within the next few days, I'll let ya'll know what happens.

 

[jd4242]

I'm pretty sure I found the smoking gun...no, I really mean it this time. I pulled my PCM and popped the cover off to inspect the board. One of the capacitors leaked, and only had one wire connecting it the the board (should have two). The one was broken/eaten through and wasn't making connection. This has GOT to be it.

I've looked into this a bit, and seems as a lot of people just get an equivalent capacitor from radio shack and replace it (or all of them since I've already got the stuff out). I think I'm gonna give this a shot, if I break it then I'll only be out a couple of bucks on top of a rebuilt/new unit. Hopefully I can get it done within the next few days, I'll let ya'll know what happens.

Im using a reman one from napa.thats gota be it or at least I hope so.thing like that can drive you crazy!!