This is a long story and I will try not to be long winded. This really started long before I became a member here and before my ECM crapped out so bare with me.. About 6 years after buying the truck my ECT just fell out. Very typical of a failed t stat. Thru the years and many t stats plus a couple sensors and radiator caps, most recently replaced them all again three weeks ago.Even sent one to @Mopar1973Man packed in one dollars and it worked fine for him. After installing a cheap Suncoast gauge from Auto Zone under the hood and it mostly told the engine temp was good. Something in the wiring. I hate wiring.

 

About three years ago I started experiencing some surging in the engine, at idle and you could feel it under light throttle. It would pop some APPS codes during these episodes. Occasionally it would rev up to near 10% and pop a 0222 code and go to a dead pedal. I would have to pull off the road and wait for the pedal to come back. I did some diagnostics and it all pointed to the APPS. Had a Timbo and just did not want to buy another without knowing for sure. So I bought a cheapy off ebay for 16 bucks. Installed it and sure enough no surging. So I bit the bullet and bought a new Timbo. Put it on and every thing was good for about 5 minutes and the surging was back. I put the cheapie back on and no surging, but soon after it popped a 0222 code but still drove just fine. Cleared the code many times but always came back as soon as I started the engine. I got worried about it and put the Timbo back in and learned to live with it. Not the best way to handle for sure but it is what I did. 

 

Fast forward to about 4 months ago and all this started getting out hand. My engine temp was down to levels I have never seen. A few times I watched it drop from 170 to 135 on the scan gauge at the snap of finger. Surging was getting worse and the cruise was going wacky. Some days the surging was crazy and it would pop the 222 code, dead pedal, and then the cruise would not turn on until the engine would surge again. Just whacky behavior. The engine was throwing codes and the 4 seem to repeat themselves. 236, 237, 121, 222. The 236 seemed to be the first one of the 4 to pop. Not sure why but that how it was happening. I remember posting about this before and IIRC @Mopar1973Man said something to me about checking the MAP sensor harness or sensor not sure which now. But I did still have my OE MAP sensor from when the ECM crapped out on me so I figure I would put it in one day and see what would happen.

 

Fast forward to today. I figured I would stick that MAP sensor in before heading back to Maryland. Pretty simple right. Well when backing the new one out I dropped the socket with the sensor in it and never heard it hit the ground. Should not be a problem beings it was a 1 1/16" deepwell socket with a sensor sticking out of it. It fell back in behind the starter and took me 30 minutes to find it. Not to mention its about 98* outside and 85% humidity and I am sweating like pig but did finally find it. Installed the old one and while trying to plug the harness on I broke the connector off of the MAP sensor. Guess it got brittle over the years who knows. Any way I put the old one back in and I am soaked in sweat and tired of F'ing with it all.

  

I just drove 450 miles with no surging and temp gauge that read normal all the way up here. It swung between 190 and 195 the whole way. I have not seen that on my dash in 10 years. I am amazed but not sure how the MAP and the ECT are interconnected at the MAP harness.

 

Anyway I am as happy as a mule eating briers but figure this will come back one day and need to figure out how this happened.

 

Any thoughts are appreciated. So much for no long windedness but if I had told the whole story I would still be type for another hour.

 

Edited July 24, 20177 yr by dripley

I got lucky one day, I found a roll of stainless steel wire sitting on the curb by the road. It's cool stuff too.

Along with all the above, a roll of rebar tie wire works pretty good.  Real easy to bend.  My favorite is a small stick with good double sided tape.  Without it that space would be full.

 

L8tr

D,

 

Well here is an update. Everything ran perfect for 6 days. The temp gauge starting wacking out again though not as drastic before. I can now see temps in the 172 to 188 range. The 237 map code came back but no others so far. The other weird thing that happened is when arriving in Maryland last Sunday I stopped for a brief moment and when getting back in and driving off the truck was way down on power. Stuck my foot in it and it just accelerated very slowly. The engine was defueled as best I could tell. Only 8 pounds of boost on the mechanical gauge and very slow accelrattion. It did accelerate to 3k rpm, but very slowly. By the time I hit 5th gear it recovered and had full power. I noticed the CEL was on before I pulled out and thats when I saw the 237 code. This has happened 4 times now, most recently today. Lasted a little longer but with my foot in it in 5th it recovered and was very noticable when it happened, like flipping a switch, no power to power and smoke. Cant help but think this is a wiring issue. I did order a new MAP sensor and oil pressure switch just in case. I am going to tear into this weekend and see what I can find. I am thinking the ground junction in the harness near the ECM break out or I do have some splices going into the ECM from the APPS sensor that are suspect. The temp thing gets me though, it predates any other problem I have had with this truck. No engine surging thru this whole episode however and I will take that. The truck is running as good as it ever has other than these glitches.    

Man that sucks, I hope changing sensors will do it, if not you probably right about wireing. Guessing vac is in check. 

.025 last time I checked about 3 weeks ago when I changed my battery cables. Since I was banging on the wiring harness while searching for the socket I dropped, it leads me to believe that is the problem. Still could be the sensor and that why I ordered one. The temp sensor righting itself after 10 years was pretty exciting though. That one still blows my mind.

Put a new MAP sensor in today. It cleared most of my smoke issues up. Ran the comp on 3X3 with very little. Before 3X1 was very smokey at lower rpm. Temp gauge seemed to holding too although I did see it drop to about 170 once. Punched several times and it did set a 236 code. Not sure why since the Comp should be boost fooling. 30 psi is the max I saw but was not watching the gauge to closely.

2 hours ago, dripley said:

Punched several times and it did set a 236 code. Not sure why since the Comp should be boost fooling.

 

If it trips again double check your MAP sensor plugs. Then if it trips again then you need to consider having the Edge Comp sent in for warranty work or service. The boost fooler is having issues.

 So I go to leave Sunday headed back to Maryland and the truck is in limp mode with a 237 code. Drove about 7 miles and got 236 code. Stopped and put some ice in the cooler. Then cleared the codes and the 237 came back very quickly and it staid in limp mode. Noticed one other thing and that was the SGII was reading a constant 14.6 psi on the MAP, assuming atmospheric pressure,  never saw that number on it ever and it never changed. The SG has never read the boost right but it has always moved usually in the high 20's to the low 30's as I recall. To late to do much last night.

 Got up this am and disconnected the Comp and it ran fine. Came back from that little ride and hooked the Comp back up and it ran fine. The SG was reading in the high 20's to the mid 30's on the map. I did exercise the all the connectors for the comp this time. Hoping that is the issue because for now I have to get back to work.

Edited August 7, 20177 yr by dripley