Throttle return

[Jim Kane]

I am having trouble with the throttle not returning to idle position. The hotter the engine gets the further back the throttle sticks.



I have been to the local dealer who in essence shrugs their shoulders. I have added two springs

pulling toward the front of the truck to get the

throttle to return to idle. Without these springs

it will run in the range of 12-1300rpm and with a load that makes it hard to stop.



My truck is a 98 12v with auto. Both the small

return springs are in place and appear normal. I took the main throttle return housing with the coil spring off and showed it to the service man and his tech. They thought the spring pressure was normal even tho I thought it was a little weak.



Has anyone else experienced this problem or have

any suggestions. The truck has about 60k on it.



thks

 

[Joe G.]

Jim, there are a couple of things to check. The throttle cable may be frayed and sticking in the housing. The other thing to check is that the kick down spring on the kick down lever on the transmission is missing. This thing goes from the lever to a place near where the transmission attaches to the bell housing.

 

[JJW_ND]

Jim:



Your truck seems to new for this to cause your problem but it sure does on older trucks and it is easy to check.



Make sure the two ball joints at either end of the throttle lever (12 - 14" rod on side of injection pump) are not sticking. They have a tiny wire clip holding them on.



When either of these joints get dry it has the same effect as the problem you describe.



jjw

ND

 

[Jim Kane]

Thks for your input guys. I did check the cable and it's o. k. , the ball joints on the throttle rod

also look o. k. Now the spring for the kick down

may be the culprit. All I can see are the two

springs that run horizontal under the throttle

rod and the coil spring in the return housing.

If I'm understanding correctly the spring runs from the kickdown down to the transmission... I'll

have to check with the dealer and see if that spring is available. When I first discussed it with the parts man he thought that spring was only for a standard transmission.



Jim

 

[Joe G.]

Jim,



The kick down spring is only about four or five inches long. It goes from the end of the kick down lever (just above the shift lever) on the transmission. The kick down cable is fastened to it from the rear. The spring hooks thru a little hole on the lever and goes straight ahead to a place on the bell housing part of the transmission. It may just be loose and hanging down. Worth a look anyway. If it's missing any transmission shop should have one if Dodge does not. This may not be your problem, but it happened to me. It seemed like the throttle pedal was really easy to push and it didn't always return to idle correctly. In my case the spring was just hanging there. I have no idea how it came loose in the first place and it has not done it since.

 

[Jim Kane]

Joe... I checked the kick down spring last night and it is in place. Soooo... back to square one.

It sure seems strange to me that something as simple as getting the throttle to return to idle

position should be something the service dept could fix without me having to resort to jury rigging helper springs. Anyways... thks for

your help in narrowing it down.



Jim

 

[Joe G.]

Jim,



Have you removed the throttle rod and lubed it? These things can get cruddy or rusty inside and stick. Give both ends a shot of WD40 and see if the affects anything. If it does then the rod should be removed and the ends lubed. Removing it is kind of tricky to figure out if you have the little wire clips that fasten the ends.



Another possibility is that the little screws that fasten the linkage lever to the pump lever are loose. There should be two of them. An 8mm wrench does the job.

 

[Turbo Thom]

Joe is right on. The throttle rod ball joints are bad. Mine looked ok , but my eyes lied. I can almost promise you the problem is there. The whole thing ain't but $48. 00 and you go new. I didn't regret it either.

Preston

 

[The patriot]

Jim you should ask your dealer to check the TSB's. Mine did the same thing (5 speed though) and it was fixed by the dealer but not after going to another dealer two times!!

I want to a local DC (didnt buy it there) and they fixed it first time. They told me there was a TSB on it and asked "why couldnt the other dealer find the TSB?"

A little off topic, I pulled my fuel solenoid, and the swivel on the bottom of the arm was rusted pretty solid. Dont rule out the rust.

HTH

Eric

PS Oh BTW mine is a 12 valve 98 also.

 

[Skydiver]

My engine just started doing the same thing. Mine feels stuck when it does return to normal.

Tim

 

[LandShark]

Jim: I had the same problem at 60,000 miles. Idle would go to 1000 or 1200 after 3+ hours of high speed driving. After cool down it would be fine. I tried lubes, grease, and taking apart and cleaning the TPS. Nothing worked! At about 80,000 miles the truck was getting hard to start and I had the dealer replace the fuel return line. This fixed the hard to start to problem and also the idle problem! I don't see how the two problems are related, but the idle problem has never come back.

 

[Jim Kane]

Well here's the story. I looked at the ball sockets on the throttle rod several times and they

looked o. k. Took the intercooler pipe out again

and took everything in the throttle assembly off

the truck. Checked cables, etc. etc. Finally took the two balls that the throttle rod hook to

off and tried to switch them from one end to the

other. Both balls worked fine in the front socket on the throttle rod but were very difficult to

get in the rear socket. The balls were very free

and swiveled easily in the front socket but were

almost impossible to move by hand in the rear socket. New rear socket is less than $10 due

here tomorrow. I belive this to be the problem.



Jim

 

[swamp rat]

I just got a recall notice in the mail today to replace the throttle cable. I wonder what they would charge to tweak my low idle when they replace it.

 

[JStordahl]

Jim: My '96 does the sticking thing occasionally, even though I replaced the throttle cable some time ago. The fix is simply lubing the linkage/cable etc. any pivot point. Works for me. I use Breakfree CLP a teflon based lube for firearms, and I just bought some Amsoil Metal Protector spray to try.

 

[Evan A. Beck]

Disconnect all throttle linkage at the injection pump, mainly at the throttle rod at the BACK of the pump, near the governor. This is where the back end of the double ball-joint rod is connected. Get it so the actual throttle is completely isolated. Move it back and forth, simulating what is happening when you push on the throttle. The part you need to isolate is circled in red on the picture below. If this seems stiff, or binds up, try shooting it with some WD40 or other type of good penetrating oil. If the oil doesn't solve the binding, it could be an internal throttle problem. Had this happen on a '94 the other day. Let me know what you find out!

 

[fest3er]

Originally posted by Evan A. Beck

Disconnect all throttle linkage at the injection pump, mainly at the throttle rod at the BACK of the pump, near the governor. ... Had this happen on a '94 the other day. Let me know what you find out!

Yup. This just happened to my '98 12V Saturday. The truck had sat for a week or more. We had lots of rain during that time. The throttle started sticking (not returning to idle and resisting increase, including pushing it past the breakover point). Turns out *some* linkage near the back of the pump was sticking. A shot of WD-40 cleared it up. I'll have to keep an eye on it, maybe use a more durable lube.



Fest3er

 

[Evan A. Beck]

This is a surprisingly common problem... That's why I always give the throttle pivot a shot of WD40 on every truck that I work on.

 

[fest3er]

Originally posted by Evan A. Beck

This is a surprisingly common problem... That's why I always give the throttle pivot a shot of WD40 on every truck that I work on.

Might this help to explain frayed throttle cables?



Fest3er

 

[Evan A. Beck]

Definately can't help them, that's for sure...