1992 302 accelerates on its own
 

Ok long story short. Son just got my wife and I a 92 ford starquest (By starcarft) hitop conversion van.

we where told it was parked because it would throttle up on its own sometimes while idleing and sometimes while do 70 mph.

My first thoughts are maybe the cruize control is malfunctioninng but since I haven't had it on the road yet I can't say.

I am wondering what might cause this problem and if any one has experiance this and been able to fix it.. Thanks

Chaesman

A choice to consider, disconnect the cruise control linkage from the throttle linkage and see if it does the run up thing.
At least that would confirm if the cruise control is faulty.

after running the van for about an hour I was unable to duplicate the acceleration. I believe that the previous owner has mistaken a high idle for acceleration..

The 302 in the van seams to idle around 1400-1500 rpms and I would expect it to idle more like 700 to 900 rpms. per haps I am am wrong but it seams fast. the idle adjust ment screw is adjusted so far out that the throttle wont even touch it so this is not an option for getting this idle under control..


Any thoughts on how to lower this Idle??? Please help!!!


Also I noticed that if I shift manualy first second and drive it shifts very solid. however if I start in drive it just stays in first. You must shift it manually at this point to get more than on forward gear and I havent gotten Overdrive to kick in yet.. Any thoughts on where to start with this tranny?

My initial thought although probably wrong is perhaps it is idling so fast that it is mistaking it for being under acceleration and can't shift but who knows..

Please help me make this van right my wife loves it and wants it fixed and I am just an average joe with low income and the ability to turn a wrench and follow a manual.. (was an aircraft mechanic for 10 years in the USAF)

Thank you for any help you may be able to provide..

Sincerly
Jon

They're a good little truck.
Why not start looking for a vacuum leak somewhere. That's one of a few reasons for an unusually high idle speed. Should have a vacuum diagram under the hood . Make sure someone didn't mix up the hoses. Take the doghouse off and you can see much more that way. Its only 2 bolts and 2 clips.

Well after following the vacuum diagram to the best of my ability it apears they are all going to and from the proper places. I checked all the conections for leaks and visually checked the lines and then ran the engine and listened for leaks and felt all the lines. I managed to find 1 rather large vacuum leak and one that was a very small pin hole. I repaired both leaks and could find no other leaks. :)

Well that is one step out of the way I guess.

Unfortinatly the van is still idling very high. :confused:

I know on my ranger I would clear the odb2 computer of all errors and reset it after working on anything that produced an error. How ever I believe this would be odb1 and I do not have the correct scanner to read or clear the codes. (On my ranger it seams to force the computer to readjust everything and it will run totally different after resetting the computer) is there a way to manual read codes and reset the computer? (I know years ago I had a cavalier that you could short with a paper clip and read the check engine light flashes).

So is there a way to check and clear codes manually?

and

What would be the next likely culprit to check to get this van to idle correctly?


Thank you for all the advice that has been provided so far.. I am sorry about the delays in responding to the steps. (Just takes me a little longer than most due to being disabled)..

I do relize this is a process and even though one step does not cure the problem eventually I have High hopes we will find the answer with out me spending a crazy amount of money to put it in the shop (I will as a last resort, but want to try everything possible to cure it first)(Plus I find it relaxing to work at my own pace and learn everything I can about this engine and van)

I only switched to ford about 18 months ago and I love them so far prior to this I had always been a mopar man but things change. and I don't regret the change so far.


Thanks for any assistance you can provide.


Sincerly
Jon

You didn't mention anything about a check engine light. Does it at least come on when you turn the key on?
There is a cheap little tool sold by thexton tools.com that will really help you get any codes from the computer. It is tool # 443. Only costs $12.00. It will tell you all the codes. You will enjoy using it.
Ford has a neat little system where it will run the vehicle and test the components while it is running the tests. If there are any problems it will then give you the codes.
Two of the tests are KOEO (key on engine off) and KOER (key on engine running).
Being new to Ford, you should get a charge out of the things you can do especially with this little tool. There are more tests you can with it, those are only two.
If the IAC (idle air control) valve isn't working correctly the test will determine that.
If you remove the two hoses from the air filter that go to the throttle body air intake you may see if the throttle blade is closing completely when in idle position. It could be just a linkage problem keeping the blade from closing.

Yes the check engine light comes on momentarily when you click the ignition on but goes off immediatly and does not come on while running. I will pull the hoses from the throttle body and take a peak at the blades tommorow