Pump adjustments

[bvanetten]

I've read all the post's I can find about adjusting settings of the 1st gen injector pump but none of them refrence what a "stock" setting is. If one doesn't know if his pump is set to stock or not you can't really adjust it, you need a base line. So, how do you tell if it is stock or better yet what is stock settings.



Bruce

 

[R.E. Miller]

A good indication of "stock" would most likely be the past owner your truck, or by monitoring your pyrometer. If you bought your truck from some one who was not a diesel mechanic or a TDR nut it is a good bet that your truck is stock. I do not know of a way to tell if the screw is in it's normal setting, because all engines are not the same even from the factory. I think the best thing you could do is just read your pyrometer and tune accordingly.



Hope this helps,

Russell

 

[Midnite]

I would think the full power screw would be a good indicator. There is normally a shim installed on it so that you can't screw it in all the way. Also, mine wasn't even screwed in up to the shim when it was installed in my truck this April.



I would think anyone who makes mods to their pump would most likely at least turn in that screw up to the shim. Of course, if the shim is gone then it's a dead giveaway that the pump's been played with.



In my opinion, just from hanging out here it seems like "stock" settings vary quite a bit. If you do a search on diaphram settings, you'll probably come up with one or more threads that mention that the little dimple mark on the diaphram could be anywhere from 10 o'clock to 2 o'clock when standing over the driver's side fender looking at the pump.



I don't have a Cummins engine manual, but there may be specs in there for what you're looking for.



Mike

 

[bvanetten]

It's stock... EGT's to high!

Well, the shim is still on. It's probably as close to stock as any. EGT's are really gettin me down I pulled off the 12 housing and put the 18. 5 back on for pulling a camper this week end. With the 12 I was running 800 post turbo at 75 down the freeway empty. I figured taking her back down to stock would help... but it didn't bring it down but 100 degrees. And this is on flat ground, no hills. My trailer is about 6500 lbs and at stock settings this truck is a dog and I STILL have egt issues! Now, I don't have an intercooler (just got one off of a 94) and I'm sucking hot engine air rather than cool outside air but I'm stock again and I wouldn't think hot air would affect things this much. How are you 91 and older guys doing? What kind of temps are you running? You guys with stock trucks, are they dogs? When I get back from this trip we're putting on the 94 cooler and fabbing up a filter housing to pull cool air. It really sucks driving around a truck that you know has the potential kick butt, but you can't because your affraid of melting a piston!



Bruce

 

[Midnite]

Bruce-- could it be a pump timing issue? Maybe the timing should be advanced a little?



Mike

 

[WestTN]

Get the cooler on. You are not going to be able to add fuel without it. And I wouldn't worry about 800 degrees at 75 mph. You're safe up to 1100 to 1200 preturbo. I run a Banks aftercooler on my 1989 and cannot get the post turbo temps much over 1000 at 23 psi boost.

 

[BushWakr - RIP]

You really do need to install the intercooler before making any judgements. It will make a real diff. on your exhaust temps. and it is a really good plan to take some baseline readings before and after the intercooler install.

In conversation with Piers Harry I learned that a rough formula to use when pyro is POST TURBO, is : add 10*F for every 1 lb. of boost. So, if your running 23 lbs. boost you should estimate atleast another 230*F to your pyro reading.

I also learned that when you hit 1200* F. you are very near/at the max temp these engine's internal parts can handle. This is why the turbo exhaust housing is important to the application/HP.

You need to move more, and colder air through to keep the thing from grenading or going Chernobl on you.

800*F for a non-intercooled truck at WOT isn't too bad in my opinion, especially if your at 75 MPH. A 100* temp. reduction is also pretty good. Free up your air intake, cool the air, and free up the exhaust.

I have a mickey mouse little pic that I drew for the AFC diaphram if you want me to post it so you can see the 'offset' on the tapered rod underneath.

Sorry if I am long with this post guys.

Regards, Bob

 

[bvanetten]

Well, we made it back safely from our trip. Here are the results. 90 degrees outside temp, five mile stretch of 6% grade, 35mph max at 950 degree post turbo with 15 lbs boost. I had about 2/3rds pedal left but was really worried about temps so I didn't push it. That was going up to our camping spot. I did notice coming home tonight I was able to go a bit faster with the same temps as above with outside air temps at about 60 degrees. Tomorrow I'll start to install the 94 intercooler and cool air intake. Do you guys think timing could be a big issue?



Bruce

 

[BushWakr - RIP]

You can certainly post to some of the more experienced guys on here but believe me they are all integral.

One changes the other and so on.

I absolutely do NOT know it all, in fact far from it.

I have learned that if you mess with one, expect something else to change, and not always in a good way.

Timing is important when 'up-fueling', it reduces smoke, helps to compensate for the timing effect that installing diff. injectors have.

eg: if your new injectors have a higher pop-off pressure then that will change where/when the fuel is injected,how long that process takes, plus a richer fuel mixture. Timing changes will affect smoke, EGT's and performance. And so it goes. I'd love to see one of the other fella's add to this thread. Perhaps Piers would be good to jump in here.

FWIW.

Regards, Bob

 

[Midnite]

Originally posted by BushWakr

Timing is important when 'up-fueling', it reduces smoke, helps to compensate for the timing effect that installing diff. injectors have.

Bob, This is something I've been wondering about--specifically whether it would be worth it to advance my timing to 1. 4mm before getting my PWs, or would it be best to wait until I get the PWs in, and then advance the timing?



Mike

 

[BushWakr - RIP]

I really don't know if it makes alot of difference when you do it to tell the truth. Making the adjustment now certainly can't hurt anything, and it would likely improve your performance,less smoke etc. You may want to inquire what it should be adjusted to, based on your intended injector choice, then go with that adjustment as soon as you can afford to do it.

I've seen settings ranging from 1. 35mm to as much as 1. 70mm.

In a conversation with Piers last year he noted that he generally sets (I assume 1st Gens) at around 1. 40mm lift.

It does need to be done properly though. Mine is currently not set as accurately as the way Piers and others do it due to the use of 'timing pin starting point', being less accurate.

I would think..... go for it now. Jump in here you guys! Any other rationale thats being overlooked????



Regards, Bob

 

[Jim Curry]

I haven't had it done yet but in talking with Ted Janetty he recomended 1. 45 pump timing to me. But as BushWakr said there are lots of different settings that have been posted. Just thought I would pass along this setting recommendation from Ted.





Jim Curry

 

[Midnite]

Hmmm... interesting--thanks for the tips!



I think I will look into doing it now. Unfortunately I can't seem to find a decent pump shop in Anchorage. The one's I've called didn't seem to have a clue.



Thanks,

Mike

 

[BushWakr - RIP]

Contact Ted J. or Piers for the detailed instructions first. Then take them with you to a Authorized/Qualified Bosh shop. From there they will know exactly what you want done, and how to do it.

I'm almost certain there are some fairly detailed instructions on this site. Do a search on 'Pump Timing', or Injection Pump Timing or variations on that. Here's a thread with some good info to start with...

https://www.turbodieselregister.com...threadid=2360&highlight=injection+pump+timing

If anyone else a thread or, knows a site with this info maybe they could post the link or URL for you.

Basically though you don't want to rely on using the 'timing pin' on the side of engine. Its notorious for being 'sloppy' and will result in a 'close' setting at best.

Regards, Bob

 

[AWM]

Bruce I'm probably a little late, but if helps, I ended up using a second gen. charge air cooler and mounted it upside down I got all the conectors from turbonetics (links page) good luck, also I have dig. pics of mine but haven't hade time to figure out what to do with them (or how to post) Bob







)

 

[bvanetten]

AWM,



Upside down? Did the inner skirt get in the way? How are you running your intake air.



Bruce

 

[AWM]

yes, upside down with the conections on top otherwise they are too low,I have 1'' body lift and still its a tight fit between the hood latch, had to fab a new brace for the grill, yes I had modify the inner fender, also ended up moving the heater core inside the cab to clear the turbo, yours may be different, but my turbo has a flange that a 90' cast elbow clamps to that points it towards the cooler (sort of), had to fab the conector pipes from mandrel bent exhaust tubing. ah it never ends. Bob

 

[bvanetten]

Hey AWM,



If you get the chance, take some pictures and post them. I'm sure everybody would like to see. Also, a friend of mine has a 71 burb and is interested in a Cummins swap but doesn't want to go the route I did. He's thinking of a 4bt instead of the 6bt for fit issues. Any words of wisdom would be helpful.



Thanks

Bruce