good day,

i have a ram350 waggon 5.2L TODAY IT STARTED DIESLING (KEEPS RUNNING AFTER IGNITION IS TURNED OFF) opps cap lock sorry ..

+ it self accelerates .. when i put it into drive i get a thud as the tranny engages then .. with out applying the gas it will accelerate to 55mph+ in a mile or 2 depending on grade ... this is/was a prob from last year that self corrected it self until today ...

i looked and could not find this IAC as described .... doest look like my engine has one ?? ( ill add pics when the sun rises )
it does have cruise control ...... (which btw was/is in the off positon)

thank you for taking the time to read my post ....


[IMG]local://upfiles/47997/C7C0FF1E8492455F9221C7D20DC9BDA1.jpg[/IMG]





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i noticed this hose was disconnected and re-connected then that's when the dieseling re-stared ??

 

wonder why the img tags didnt work on the second post ??

 

what year is your van? I too get dieseling but only in the winter. I suspect mine may be timing related, because the last bit of the diesel can sometimes run backwards.

 

'88 RAM 350 Waggon yes the dieseling more prevalent in colder days ....

why on colder days vs warmer days isnt the timing a set setting ?

as far as trying to locate an IAC on my motor ?? any ideas ??

cause i do get a very high idling sometimes ...

then after an hour it starts to idle just fine ....

 

IMG tags only work if you dont do a fast reply.

On the IAC, I dont know what year they started putting them in. I've not found one on my 87, but 87-88 was when they did alot of model changes, or I havent found it yet.

The timing is a chain under/behind the water pump. I dont know if it is possible to adjust without removing that, but it is checkable though Id suggest a repair manual of some kind to verify the procedure. Fixing my van is more of a hobby than a job for me. The timing can change as the chain streaches and the chain and gear wear together. If you end up needing to replace one, get the gears and the chain together. I had an issue with my 83 van that had the timing chain slip some how and advance an outragous amount (20 degrees was mentioned by the shop but may be hearsey) but I was able to keep sorta running because the engine was hot. I had no power and top speed was about 25-30. It was a long slow drive home.

I suspect, that the dieseling is caused by over advanced timing, or maybe a too rich mixture. As for why on colder days, I think has less to do with the temp, than the fact that the gas mixture changes in the winter, or so I've heard. sorry Im not more help than that. I should try and plot the temp, length of drive and how much the diesel is to see if there is a pattern, since mine started doing it again about a week after I replied to your message.

That large thunk you hear may also be a faulty U-Joint on the drive shaft, which if left unfixed could cause the driveshaft to seperate. The way to check it is to block the tires and put on the ebrake. Then try turning the driveshaft by hand. If the middle wiggles without the ends moving that is that problem and is unrelated to the other issue.

 

Your vehcile does NOT have an IAC. That's on the Gen-2 Ram Vans with TB Magnum engines.

Your vehicle has an ICS instead if it's a Holley. However, from your pictures it looks like a Rochester-QuadJet, then it has a ISS (Idle Speed Solenoid). It's listed in my Haynes Repair Manual book #30065 on page 4A-13.

NOW, where your finger is pointing to a hose and a cylinder type part, I would think that the thing is an old PVC valve that either needs to be freed up inside because too much junk is clogging it up or it needs replacing. Typically, soaking it carb cleaner will free up this part. Shake the part with the cleaner inside too and dump out the crude inside of it. Air dry it well and put back in. It it's not the PVC valve, it's the air check valve.

You may need to check the Mixture-Control solenoid on the Roch-QJ. It's next to the carb air horn. Or the Lean and Rich stops are now out of adjustment on the Roch-QJ. Hayes has a special manual just for this carb. They will not go in any depth in my Ram Van book beyond that. The book is #10230.

From the looks of the pictures, have you carb cleaned the carb lately? It has some staining on the inlet valves and could use a bottle or two of concentrated cab/injector cleaner at 1/2 a tank to flush out the gum up inside.

 

Check your high idle cam on the carb and make sure it isn't engaged. If it is, you'll get a high idle which will in turn cause the thud going into gear, the acceleration over a mile, and it will cause dieseling when you turn the key off. Because of the change in pressure from the choke coil, it probably self corrected itself when the weather got warmer and is now back because it's getting cooler outside. One other thing to check it that the choke take-off diaphragm is not leaking (side of carb). If it is it will not drop the fast idle cam from the high step down to the low one when the engine is running.