My work van (former church maxi van) shut down the other day on test drive by potential buyer. Would start then die, if you got it in gear it would go and seemed fine. I have replaced the idle air valve several times, the code in past did say Idle air circuit. My tech has also replaced the crank pos sensor because I was having some rather violent lurches and loss of power. The one he put in caused a ticking noise and was hitting either the flywheel or whatever is near. It went for a while with no code but came back with CE light and have not gone to get it checked. Looking for wiring diagram to check out wires from idle air valve to ECM. Tech says these computers have problems. Considered going for rebuilt plug and play but need to make sure that is it. Appreciate any help.

 

I wonder, since you had replaced the iac, how did the port look after taking it off? If it was black and cruddy it might be a good idea to pull the throttle body off and give it (the whole thing) a good cleaning. It's inexpensive and really not too difficult a job. There are some good DIYs and videos to be found that are helpful.

if the Crank sensor is hitting the fly wheel, not good and wouldn't count on it lasting long before the engine will just refuse to start period

from all I've been learning one thing you might consider is the brand of sensors and iac... sticking to oem Mopar replacements is your best bet.
So it's pay at the dealership or find em cheaper through ebay or amazon

 

Thanks, went out an pulled the crank sensor, flywheel had been slightly kissing back. There is part of the molded covering that extends up the bracket. I noticed that the whole thing would rock slightly on it and not fit flush to engine block. I dressed it slightly with file and it fit snug. The light clicking I was hearing before is no longer there. I had cleaned the orifice for the IAC and hosed the throttle body when I replaced it before my tech did it this last time. Interestingly while trouble shooting today I pulled the connector off and it idled fine either way. I traced the four wires from IAC to the driver's side connector on ecm and ohmed them out ok. Just have to drive it. The first time my guy replaced the Crank sensor it came from Autozone. I had complained about a moderate ticking from that area, it laid down on me and they towed it back to shop, he pulled it and you could see pretty good gouge on back side, they brought another one (the one that is on it now). Will have to drive it a little to see. When the original (to me) one and the first replacement crapped out it was like a bucking bronco and I thought I was going to loose rear end. Thanks. Mine has 98090 mi. I had cat converter failure and put test pipe on it until I make sure everything is right before putting aftermarket new on.

 

one of the first things to look at with one of these older vans is the condition of all electrical grounds to the body... a ticking crank sensor just means it needs to be adjusted further from the flywheel... there is enough slop in the mounting to do that... My 2001 van had similar symptoms and after a tow to the dealership and 2.5 hours of their time, the engine ran for 3 days, but then the same symptoms returned and was never able to resolve the issue last spring... the Dodge tech shrugged his shoulders when I asked what he did to get it to start... my CEL gave the written code on the dash after about 10 seconds with key on and no start "NO BUSS" which is a communication issue to the computer...

 

the computer is likely suspected

 

Thanks, any idea where these grounds are located on 2000 3500 ext? On computer has anyone had experience with any of the guys who offer repaired plug and play exchange units? I am getting rid of it but do not want to sell someone a problem. My trusted tech says may be the pcm. Wish I had my 68 Road Runner back, it would not haul as much but it would haul a**. Found four small gauge grounds on firewall and one large on driver's side rear of eng block, loosened them all and re-tightened. May be my imagination but when I cranked to move out of back yard it seemed to start and run better.

 

I bought a PCM out of Miami last March... I was stranded in a campground in FL with a starting/running issue that everyone on this forum told me was a PCM issue... and I agreed, as I had done most everything else I could do to repair the intermittent issue, which included a "NO BUSS" instrument display.

I ordered ($300 plus shipping) early on a Friday via a telephone call, they said to expect it Tuesday, Wed at the latest... It came on Friday... so much for fast shipping...

I installed it and long story short, my same symptoms remained, telling me the rebuilt PCM was defective or something else was wrong. After many hours of work and parts replacement van would still only run intermittently. Two months after original sale, the rebuilder (allcomputerresources dot com I think) called and wanted their CORE back or otherwise they would charge my credit card another $100... I asked for more time as I explained " I am still trying to figure out my problem", which I never did... I never heard back from them nor did they charge me another $100.

I did more research on failed auto computers during this time, and there is tons of info out there about these complex electrical problems and the scamming producers that rebuild or at least supposedly test these used PCM units. The mechanic is between a rock and a hard place. I don't doubt the rebuilders put the PCM on a test unit of some sort, but I really rather doubt they extensively test them for a long period of time on an actual test engine, causing anyone that buys a rebuilt PCM, ECM or whatever acronym you want to use... even more headaches and wasted time and money.

I called a Dodge dealer while in FL to help fix my problem and they wanted $900 for rebuilt and $1000 NEW for a PCM for my '01 B3500 van, with NO guarantee on parts or labor that it would actually fix my problem. I had already paid them $260 for 2+ clock hours... the van started in their shop after I had it towed in, but the mechanic had no clue why it started or what the NO BUSS error ( he showed me in the parking lot before pushing into the garage) went away. I will say the van ran for 200 + miles the next 3 days before I had another problem which then NEVER went away. I figured that if I was going to spend in the neighborhood of another $13-1500 more on dealer repairs, parts and labor with no guarantee, I might as well just throw my money away.

I sold the van for parts in Dec...

The grounds are anywhere that you can find a wire. I actually used new drill screws and made new holes into sheet metal and cleaned up the connectors. There were a couple of engine grounds on the left side near the alternator also. Check inside the black fuse box alongside the battery... if anything looks corroded in there, then take out the box and look at the underside where the wires come in to the fuse taps. Get some electrical contact cleaner from a specialty or auto store to use to clean any corrosion on contacts. Look at the fuse panel on the side of your instrument cluster and under the dash, which you may have to remove to get at. My '01 also had a Body Control Module (BCM) mounted below the radio that is also hooked to the PCM and controls some start/run functions, as does the dash cluster.

I hope you have better luck.

 

"seemed to start and run better"...atta boy!!!!!!!!!!!!!!!!!!

 

Thanks, I looked for all the grounds I could find, under dash with dog house off, did not see any fuses under the hood . only the fuse block. Did see one relay just aft of the remote door locks. Maybe base 2000 may be different. I see ref to auto shutoff relay in some diagrams but do not see anything resembling, the fuse/relay panel does not identify any below fuses on cover but have not looked in owner's manual. The last code shown said Idle Air Control Circuit. Have not reset recently. In past when it acted up like this eventually the light would go out.

 

Maybe I will get lucky, thanks.