1998 Dodge Ram Dies when you come to a stop.

Tiny
BOOMER73
  • MEMBER
  • 1998 DODGE RAM
  • 6 CYL
  • 2WD
  • MANUAL
  • 105,000 MILES
I had my Fuel pump replaced about 1 1/2yrs ago, and about 2week after that my truck started dying everytime I let off the gas to come to a stop. You can rev the engine and it tries to idle but then dies. I've changed my Air Filter, Spark plugs and wires, PVC valve, no fix. I took it to the Dodge dealer, they put in on the computer, but nothing. They cleaned the thottle body, and it helped for about a month, but it start again. There is no engine light, and the computer doesn't see anything wrong. I thought maybe vacuum, but I can't find any leaks. Maybe fuel filter, EGR, IAC, I don't know? Need best quess. Truck runs fine, and starts fine, and will idle, but won't idle if you press and left off the gas.
Do you
have the same problem?
Yes
No
Thursday, March 11th, 2010 AT 2:39 PM

4 Replies

Tiny
CARADIODOC
  • EXPERT
This sounds typical of what happens after the battery is disconnected or run dead. The Engine Computer must relearn "minimum throttle" before it will know when it must be in control of idle speed. To meet the conditions for the relearn procedure to occur, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the brake or gas pedals.

If that doesn't help, your mechanic can connect a hand-held computer, called a scanner, to read the number of "steps" the Engine Computer has commanded the idle speed motor to. The motor can position itself from 0 to 256 steps. Step number 32 is typical for a properly operating engine. If the number is much lower, the computer is trying to slow the engine down or minimum throttle hasn't been relearned. If the number is much higher, the computer sees that idle speed is too low and is trying to do something about it.

Caradiodoc
Was this
answer
helpful?
Yes
No
Thursday, March 11th, 2010 AT 11:07 PM
Tiny
BOOMER73
  • MEMBER
I tried that twice, still not idling. About the scanner, I'm believe they did that at the Dodge dealer. They said they hooked it up to the computer, and ran tests on it, but they didn't see anything wrong.
Was this
answer
helpful?
Yes
No
Monday, March 15th, 2010 AT 1:19 PM
Tiny
CARADIODOC
  • EXPERT
It would be helpful to know what step the Automatic Idle Speed motor is asking for, but based on your comment about it working for a month after the throttle body was cleaned, you might look there again.

Loosen the AIS motor bolts, then, while the engine is running, pull it out a little. The two torx bolts holding the AIS motor on can be hard to remove so be sure to use the correct size tool to not round them out. Idle speed should increase quite a bit. If it does not, pull the motor off and check that passage for carbon buildup blocking air flow.

If idle speed does pick up, block the hole with your finger. If idle speed goes back down, the inlet side of the passage is blocked. If idle speed stays high, the entire passage is clear.

If carbon blockage seems likely, use carburetor cleaner and a small brush to clean it out.

Caradiodoc
Was this
answer
helpful?
Yes
No
Monday, March 15th, 2010 AT 3:38 PM
Tiny
BOOMER73
  • MEMBER
I just wanted to get back with what I found. It looks like a bad battery connection. I found this on a similar question in the forum, and someone wrote in about the battery connection. So I clean my terminals and clamps really good, and now my truck is idling fine. I never had a problem starting the truck, no problems electrically (lights, radio, wipers). But I never would have thought that a bad connection would cause an idle problem.
Was this
answer
helpful?
Yes
No
Monday, October 31st, 2011 AT 2:18 PM

Please login or register to post a reply.

Recommended Guides