i have a first gen non intercooled truck. it is a low mileage truck. was a uhaul cab and chassis. the pump has never been modified. i took apart and put 3200 rpm spring in. I was very careful to check shaft index. This shaft is different that what most describe. THe throttle lever only has 3 lineup clicks instead of 4. I dont know if that matters or not. I did verify spring in place was 386. After swap i cannot get idle down if I use stock throttle lever notch. If i back it up a notch I can get idle down but max rpm is then only 2700. even then i have to back off my fuel screw several turns from stock. It just doesn't make sense to me. In everything i have read it doesn't seem like any others have near this much issue with idle after gov spring change. Any help would be greatly appreciated.

 

Welcome to the forum, let me get this straight, you replaced the 386(stock) spring with a 366 spring AKA 3200 rpm spring correct? Tou re-indexed the throttle shaft to the 2 and 4 o'clock position and it idles high. have you backrd the high idle screw out or is it idling high even after you do that? if it is sometimes you can re-index the throttle shaft to make it work right. Some pics of the throttle shaft indexing and pump might help some

 

Turning the fuel screw will have a big effect on the idle speed as well.

You have to adjust several things properly, to get it all to work just right.

Are you getting full throw on the high idle side? Is the low idle screw touching the linkage when at low idle? Have you back that screw out to lower it?

How are you checking RPMs?

 

Yes you are correct. Still idles high with idle screw backed up and fuel screw backed out. See how this lever only has 3 marks.

 

I guess my biggest issue is I didn't think I would have to reindex to make this work. Now it seems I would almost be better off with regular spring and just playing with linkage to get rom. In the end what will be better? Reindexing and using more fuel screw or leaving in notch and backing fuel screw way out to get idle down?

 

Something is not right.
In that picture you are not even touching the high idle screw. Have you loosened your adjustable throttle rod, to get it to touch?
That might be what is holding you up from allowing it to rest on that screw, and thus lowering your idle properly.

 

Sorry pic was just for looking at index marks. Yes even if I put spring on and idle touches the stop it will still be high

 

I see that the screw for the idle is still out there quite a way have you tried backing it out (or in) to lower the idle? if you back it up so there are not so many threads showing it should idle down

 

I see now im gonna just have to either reindex and work on throttle adjustement and fuel screw. My question is more advanatageous to adjust it/reindex so it idles with fuel screw in close to max or does it matter whether the idle is adjusted lower by backing out fuel screw? I think i can adjust things and make it work either way but to make old index work I think i will have to back out fuel screw, but it does seem more responsive like that. I mean it pulls spring earlier.

 

Myself I would use the idle screw to adjust the idle as that is what it is there for

 

So just to post a follow up. I was able to back off the throttle lever index one click. It will then idle with the fuel screw in to where it was initially. The idle 750 rpm will occur only when it’s backed up to touching the injector pump housing. I then changed the throttle linkage attachment to the hole closer to the pivot point. This allowed to get me more pull. I was in able to get a full poll on the throttle and get 3250 RPMs. So now I can idol it 750 and get 3250 and the fuel screw is in Close to start may be a little further. So everything works well but I’m just curious as to why I had to do all of this. Someone said well maybe you didn’t put it back together but I took it apart twice and this is not my first time doing the pump and I’m sure it was together right. It was a pretty good difference in the spring lengths and I think that is the biggest issue. Thanks for all of your help

 

I am having similar issue. Just swapped to a new DAP pump with 3200 spring. After swapping I bled system appropriately and trying would not start without starter fluid and it was rough. After this I tried breaking bolts loose on ve pump that holds it to timing cover and rotated pump head with ratchet strap to adjust timing moving AFC head towards the intake plenum adjusting timing. After this tightened up bolts removed strap and it started right up but high idle.
tomorrow I’m going to see if I can adjust it through the pump.

 

Did you buy the new pump that didn't require a core? This one here ? https://www.dieselautopower.com/dies...ed-0460426205a

"

"Product description

DAP VE Pump for Intercooled 91.5-93 5.9L VE Stock-Aftermarket Performance Calibrated with a 3200 Spring-- No Core


"Pump is not performance tuner" (say what?) "

Product description

DAP VE Pump for Intercooled 91.5-93 5.9L VE Stock-Aftermarket Performance Calibrated with a 3200 Spring-- No Core

Product description

DAP VE Pump for Intercooled 91.5-93 5.9L VE Stock-Aftermarket Performance Calibrated with a 3200 Spring-- No Core


Pump comes with a 6 month warranty." It looks like it is a Chinese built pump with a 3200 spring swap.

 

Ohh now they have Chinese knock off VE pumps for sale?

Something new for me to look out for staying away from.

Like the Chinese turbos, I have seen cleverly called Turbone. I have a good idea while it has a "bone" in the name.

 

The link is the one I got ya, today I’m gonna try to adjust pump and try a couple things see if I can get it to normal.