How critical is a calibration, when changing the spring (366)?? I haven't heard this to be an issue in the previous posts.

I had a leaky VE pump, (o-ring at distributor plate) and am having local shop do a 're-seal'. I asked them to change the spring while they're at it, but they wouldn't do it without doing a calibration (an Extra $250...for putting pump in the test bench) the re-seal and throttle bushing is less than that. The truck was running fine, and only 145k miles, so I'm not inclined to calibrate. Shop said 50% chance the spring will mess up the calibration, and it will no longer run correctly.

Maybe I'll just have to do the spring myself, but thought it would be EZ to do since they have the top off anyway.

The truck is gonna be sold as soon as it's back together, so the performance is not a big deal to me, but I would like to be a 'nice guy' for the next owner.

jb

 

Just mark the screws positions before you remove them. Be sure you back the fuel screw out before you put the cover back on or you'll break the lever off like I did.

As a result I had to remove my pump and replace all the gaskets and o-rings. The fuel screw is the most critical but seeing as most everyone here has cranked theirs up a couple of turns it isn't a big deal. I had all of the screws out and it isn't rocket science. The timing should be marked already but if it isn't you should mark it before you move the pump.

Have you seen the sticky for the 3200 spring install?

Edwin

 

$250 to run it on the stand? I got mine rebuilt for $450, included the rebuild kit, throttle bushing upgrade, and the timing advance piston. Truck went from 15mpg to 20mpg city.

Daniel

 

If you're sending it down the road, leave the stock spring in. Un-modded trucks bring more money

 

I'l concede that a modded truck normally wont bring more than a stock truck. If you are going to sell it as soon as it runs well again, I'd leave the pump stock, tell the shop you want 3000rpm (that is doable with the stock spring), and tell the buyer about this site.

Most of the general population think the stock Cummins is srong enough. Though I have sold one or two I have tuned because it "ran like a scalded cat." One guy who bought my last 93 said the performance was "outstanding" and would leave his PSD behind, and it had a 12cm housing with some mild pump tweaks.

DP

 

after inquiring more from the pump guys, they seem to tow the BOSCH party line, and don't do any mods that would upset their Cash Cow. They have far more than enough VE work to feed a small army. (lots of VW problems with ULSD and bio-d...)

They wanted $660 for a total rebuild, which I considered a tad spendy... but then they aren't too hungry. They resealed the external stuff; plates on both sides, top...+ dist o-ring, and lift pump modulator(?) (the 3 o-ring doo-dad on front corner) + throttle shaft for less than $200. Hopefully it will give long service.

My '91 will be sold stock, and I'll tweak my '93, if I can't find a bigger truck before I get around to adding my 12cm / DTT TC, BHAF, 4" exhaust + ...?.

 

I often wonder if a rebuild job consists of anything more than replacing o-rings and seals along with the parts that are worn out of spec. Any manuals for these pumps seem to be a closely guarded secret so how to tell if a part is worn is practically impossible.

I can tell you that a seal job isn't that big of a deal and is a good idea even if the pump isn't yet leaking. Mine had about 160K on the engine and the front seal was very worn. I'm sure it would be leaking with the new lift pump pressure.

Edwin

 

Yep, that's just an excuse to stiff you for $250. I haven't heard of a spring install going bad that wasn't directly botched by the user in some way. With the pump off the engine it would be too easy to just put the spring in yourself before re-installing the pump.

 

$200-250 is about the going rate to put a VE on the test stand.