Idle problems

[mudcat]

I've been having some eratic idle from time to time. Sometimes it will idle down to 700rpm when coming to a stop. Other times actually more now than before it will be around 900rpm especially after a 20+minute run. It is still ideling faster even the next morning after siting all night and will do it for a while maybe all day even. Sometimes it will idle down to around 600rpm and actually lope some.

I have tried changing fuel filters and screens, adding fuel conditioners and even running biodiesel doesn't change anything.

I changed the fuel pin the other day and it may be slightly worse than before as far as the higher idle is concerned. Yes I did lube it up before installing it.

Sorry so long, Thanks in advance.

 

[BushWakr - RIP]

'Cat... it's really starting to sound like you have a pump on the way out... we've had a few other's in here that have had the same problems and the pump turned out to be weak or failing... you may have a bad/cracked/broken spring in the pump... there are two that keep the cam and roller ring in contact with each other and if one of those weakens or starts to fail it will cause the symptoms you describe.

Maybe some of the guys can make a few more suggestions before you have to go that route though... lets eliminate some of the easier stuff first...



pastor bob...

 

[Greenleaf]

ummmmhhhh... . sound like pump to me, kemosabay.



GL

 

[mudcat]

Today on the way to work it was perfect all the way 35 miles. Then on the way home ot was low about 600 all the way home. It doesn't fluctuate while driving necessarily it is either one of the 3 for an extended time. Nothing seems to be coinciding with it. I sure hope it isn't the pump. What are my otpions if it is? I have read about a 240hp pump, how do I find one of these. I have a contact at an injection shop but don't really know for sure if they are into what I am doing or not. They have been in business for over 30 years though.

What now? Pull the shut off selonoid?

 

[cerberusiam]

I will second the above, time for a pump rebuild. Go talk to your diesel shop and ask them about rebuilding your VE pump, most authorized Bosch shops should be able to do it. Get a feel for what they do when the rebuild the pumps, ask about turning the pump up, adding other parts, etc.



Or call Bob and order a Piersified pump.



Good luck.

 

[mudcat]

OK I may have gotten lucky. No metal shavings in the shutoff selonoid hole. But when I was checking this I noticed that there was no low idle lock nut on the the adjustment screw. It was all the way to the rear allowing for the idle to be lower. The other night after coming back from the pulls down the interstate it was running at the fast idle. The next morning the same thing. Usually it would be fast after a long sustained highway speed drive. When I looked at the pump saturday morning when it was running fast the idle adjustment was against the stop. Same with when I put the new pin in it was against the stop but I didn't notice it was missing the lock nut.

I think the adjustment was working it's self forward thus making the idle higher after a long drive at high speed. Then around town it was working it's self backward allowing the adle to be held by the throttle rod. The adjustment bolt turns very easy when you can get a screw driver on it I mean very easy.

What do you think? Possible?

I put a piece of tiewire through the hole in the end of the adjusting bolt to hold it until I can get a nut to lock it down with. I'll let you know how it works tommorrow. It may be a waste of time but for now it sure sounds better to me that getting my VE rebuilt.

 

[Greenleaf]

Have you checked your lift pump PSI?

Did you plan to attend the work day/cook out on Oct. 2nd,,,or am I getting you confused w/someone else. If your there I'll bring along a test guage and adaptor to check this if you haven't done so.



Scott

 

[mudcat]

Ok I drove it to work today it idled 750 there and home I came home the interstate. I would like to think I have solved my problem. Just have to see what happens.

Greenleaf, I'm going to try and make it to the work day meet. I think I have everything worked out so I can make it. I'm hoping to get my stacks in before the trip. I hope to get to meet all you nice fellers. Oo.

 

[BushWakr - RIP]

I think you found your problem... ... the adjustable throttle linkage can work for you and against you depending on the situation and in this case it was just a mild bit of "against you" but atleast it didn't allow you to have the engine just die out...

Keep in mind that the low idle screw also affects your adjustable throttle linkage, and the breakover spring setting too...

pb...

 

[DKasper]

Glad it seems to be fixed. A couple of months ago I started getting an erratic idle, but it was an "up & down" type -- like someone was rhythmically tweaking the linkage. It would fluctuate about 75 rpm. It turned out to be my pump. When it was rebuilt, we didn't find anything major, just some worn seals and tired springs, but the rebuild fixed it.

Hopefully you won't have to go that route!

 

[carlwest]

I am having the same problem right now, exept mine will go from a normal idle to serious loping or die completely. Even at half throttle there is some rpm variations. 92 auto. There is alot of play in the throttle shaft, so I ordered the bushings to rebuild that as well as the throttle shaft. Have about 180K and just replaced the fuel supply pump and filter. Runs smooth and has plenty of power at full throttle. Oh, KSB sensor is not working, and Dodge dealer cannot locate the part #. Any help would be appreciated.



Oh, Greetings everyone, I guess I am a "newbee" to the posting, have spent hours pouring over all your info though. Got me out of lots of jams, rebuilt my TPS ect. Thank alot!

 

[DRettie]

hmmm... just a bit of for what its worth, check the adjustment on the throttle cable to pump linkage ( threaded rod with plastic ball cups, adjustable ) to ensure that the linkage is not out of adjustment and slightly binding at times . this has happened to a few of my ctd's and seem to be ok with a proper adjustment and lube of the linkage. it may not be your issue, as you seem to have had the problem settle out, but it takes but a moment to check. pop off one end of the treaded rod and see if the linkage or cable end move so that the length of the adjustable rod is correct... if not, adjust till the ball end meets up with the rod without tension one way or the other... cheers darren

 

[BushWakr - RIP]

If your throttle shaft is leaking and real sloppy it is possible to have air getting into the supply side of the injection pump, that would make the general operation of the pump a little erratic. When you go to remove the pump top look into the AFC chamber down were the guide pin protrudes from. . if you see fuel in there you also have a leaking o-ring and that will need to be replaced as well.

Once you've done these repairs, if your problem continues it begins to sound like one of the two large springs that keep the cam and roller ring in contact may be going on you. This has happened to a couple guys in the last few months or so. Those springs are really heavy duty and they only need to weaken a bit to become problematic for us...



Let us know how you make out on the other work when you're done ok...



pastor bob... .

 

[mudcat]

I seem to have solved my problem. I took it on an extended interstate drive this past weekend and no variation at all. It has been rock solid at about 775rpm since I got it adjusted and added a lock nut to the low idle adjustment bolt.

Carlwest I hope you get lucky and it not anything major too. Keep us posted.