Idle drop, hard start

[RHelsing]

Hello All,

I am new to your group and come looking forknowledge I have a 93 Dodge W2500 4x4 with B-Series 5. 9 Cummins A/T & 96K miles, I purchased it in 93 w/3K miles on it. I have always performed my own service with no problems. But after my last service my truck has developed some symptoms! And I am having trouble figuring out what the problem is. Symptoms Are: Idle drops after motor warms up. Drops from 700 rpm with A/T in drive and A/C on to 450 to 500 rpm. Motor has even died out all together. If you shut down or "motor dies" it is very hard to start. It will crank over and not fire as if no fuel! Let it rest an (1)or (2) hours and will start right up. Runs fine the rest of the time power seems fair when cool never any problems before! The warmer (hot weather, pulling a load, long runs) the truck gets the more noticeable the problem. I have at this time done the following. Replaced fuel filter (2x), checked manual shut down valve, electric shut down valve, bleed low pressure fuel lines, test fuel pre-heater, inspected throttle linkage Am looking for any help or information I can find.

Thanks

rhelsing

 

[GeneH]

rhelsing, if it was runing fine before the maintenance seems this would be a clue as to where to look for the problem.

Above the fuel filter in the top of the fuel heater housing is a O-ring. Is the fuel heater housing tight.



Gene

92 350 4x4

 

[RHelsing]

GeneH,

Thanks for the reply. I have checked and double checked everything related to the service that I can think of. I checked your Ideas out with no luck at solving the problem. Checked the fuel pressure to the injector pump and it was real low so I replaced the lift pump. Still have the same problem and am still looking for the cure.

Thanks RHelsing

 

[BushWakr - RIP]

First of all... . WELCOME!!!

I'm not sure what to suggest. Perhaps you could post exactly what "service" was done to your truck. That may lead to some more ideas. I'll watch for your reply.

Regards, Bush'

 

[RHelsing]

BushWakr

Thanks for the reply. What I did was Oil & oil filter change, clean & recharge K&N, remove fuel filter and replace with new wix filter after filling with fuel. Started & ran to check for leaks found none.

Problem first occured on the way home the next day. Thought that I may have gotten air in fuel. Bleed low pressure side of system. No improvement. Mabey I got a bad filter! Purchased new mopar filter & install no change. Since my original post I purchased an autometer fule pressure guage and installed it in line between filter and injection pump only had 2 to 3 psi felt that indicated a lift pump problem. I read the Cummins service & repair manual to say should be 25 psi . Replaced lift pump still only have 10 psi. Is this correct And still have problem

Thanks

Still Confused

RHelsing

 

[BushWakr - RIP]

I hate to admit it but I'm suckin wind on this one. One thing I would suggest is (I did this and it helped a rough idle) up the park/neutral/no AC idle to about 800-825 RPM. When I did this my idle with trans in "D" and AC on Max drops to about 725 Rpm. For me anything less starts to get a bit rough. I can see that if your too low to start with, the drop when in 'D' with AC on could be too much for the thing to hold onto. I don't know how this would be an issue just when hot though. When cold the KSB solenoid advances timing and ups idle speed/reduces smoke so perhaps when that solenoid cuts out the timing falling back + AC + "D" is too much. I would really luv to see some other ideas on this too.



Curious too, Regards, Bush'

 

[hdm48]

Hi there. I had a friend bring his rig over with a problem kind of like yours. here is what we found.

the idle was set using the thrttle linkage and not the stop screw. put some slack in the linkage and set the idle using my photo tach and no more stalling.

we ahd the timing set at Northland Diesel.

turned the pump up while we were at it and it's a whole new truck.

 

[BushWakr - RIP]

hdm48 is right,, using the throttle linkage to adjust idle is not good. It needs to be done with the idle adjustment screw. Also there is a "breakover spring" which has to be in the proper position once idle is set. Its a funny little thing with a pin in the center of two sping ends. If this is not set properly you don't get full release on your throttle. There is a picture of it in the serv. manual. Its a bit hard to describe so try to locate a picture if you can. I'll try to scan one in and post it for you. Once you adjust your fuel settings (eg: full power fuel, afc, star wheel etc. ) you (I did) will likely find that an idle adjustment and breakover spring adjustment is needed. The adjustment is not hard to do just hard to describe.





Regards, Bush'

 

[BushWakr - RIP]

First of 4 pics.

 

[BushWakr - RIP]

Second pic. .

 

[BushWakr - RIP]

Third pic...

 

[BushWakr - RIP]

Fourth, and last...

There ya go, thats it. Hope it helps!

 

[RHelsing]

BushWakr,

And all of you who offered advise and suggestions, thank you for your attempts to help with my idle problem. I was unabel to find the problem so I broke down and took the truck to Cummins NW

and had them trouble shoot the problem. For $165. 00 thay were abel to confirm my fears. Injector Pump going out Don't missunderstan my statment I am not complaining about CNW thay did just what I requested and were very helpful, thanks in part to an old aquaintance I new from my misspent years as a truck driver who is a service writer there. (Sorry I'm wandering, I guess I am still in shock from the estimated cost to repair $1575. 00 ) I would like to know if there are any ideas or sugestions as to how to best procede from here ie: improvents to make as long as I have to do this,or where to get the best deal on a replacement pump, or tips on making the replacement, anything of this nature. Thanks again and thanks in advance for any further help.

RHelsing

 

[Hutchew]

Sounds like a common problem......

RHelsing, are you sure you didn't suck up a powerstroke and get it stuck in your air cleaner? It's real easy to do, and I know there are a lot of guys here that have had the same problem I am really suprised noone mentioned this before... .....

Seriously though, I was trying to find out what the difference between a first gen and second gen (P7100) pump was, and if a P7100 would more or less bolt onto a first gen motor. I know there is a lot more you can do with a P7100 pump, first of which is more and easier performance mods. I didn't have much luck in finding anyone who had done it, and then I found an early 98 motor for my conversion, so I kinda dropped the subject. I believe I would, if it could be done cheaply enough, convert it to a P7100. Cost would be the *****, but you gotta buy one anyway, right? Just rambling, thoughts of an idiot...

 

[Matt S]

I would check with Big Don on a price for a 230 hp pump. Why not get a little performace boost at the same time.

 

[KEENO]

Lift Pump Pressure?

Hello RHelsing! Welcome...



I looked up to verified the lift pump output & pressure for our Rotary-Style VE Pump equipped First Gen's and here's what I have found.



According to my '92 manual:



"Minimum lift pump output pressure is 21 Kpa (Or 3 PSI). Lift pump output volume is 0. 75 liters per 30 seconds of engine cranking"

The spec is between 3 - 5 PSI



Check out this posting by Bob Beauchaine and his experiences w/ Wentland Diesel and an enhanced VE injector pump. Enhanced VE



The topic of installing the mighty P7100 on our trucks has been discussed at length in the First Gen Forum. The BAD NEWS is that it doesn't seem all that easy to swap over. I'm no expert on the subject, but I understand that the Front Cover must come off & be updated and the cam must come out & be replaced w/ the appropriate drive mechanism. New inj. lines would also have to be purchased and the throttle linkage modified. Do a "search" using P7100 as a subject in our forum for some good reading.



Here's a few words from our resident expert H. Piers on the topic: The "P" Pump words of wisdom from Piers...



These folks are kind of in your "Neck of the Woods" and have reputations for awesome service that speaks for themselves... .



KEENO