Pontiac puller

Hello all. Many questions have already been answered by reading for 10hrs over the past few days.
But let me tell you about my new purchase and see if this is normal?

1993 1 ton dually with 135,000. I bought it in CA. on Ebay. I pulled a 32ft trailer with 3 axles with a 1964 pontiac on it back to denver and picked up another 1964 pontiac bonneville. I figured I was pulling about 6500lbs to denver and 10500 to home in Indiana.

Was told it had a 16 turbo? Don't remember any other mods. It has a boost gauge.

1st question. When I pulled the grade going into lake Tahoe it got very hot (stock gauge). and had what I thought was very poor power. Maybe 30MPH! with just one car. Hell my buddies truck is a 460 gas and would pick up speed on a climb like that and not overheat with the AC on. >

Also after I picked up the second car in Denver (thank God it was flat after that) My top speed was 75 going down grade. My boost guage will go to 25 if I smash the pedal on the floor.

How do I tell if any mods have been done to the pump or injectors? I do not want to "Bump the pump" if its already been done. I did change the oil and fuel filter today.

Also I only got 7-8MPG. Is this normal? That would be OK if it was a 460 gas ford and I could do 100MPH. But I bought the diesel for more power and fuel economy. ???

I know its a lot of questions but any help would be greatly apprieciated.

Alway buying 1960's pontiacs!
Thanks,
Steve

DodgeCowboy

I am no master mechanic on diesels yet but a buddy of mine has a 94 that was the same problem and it was the diesel pump was tuened wayyyyyyyyy down and not alowing diesel to get to the motor. Corret me if iam wrong guys

furious70

I assume you've read the instructions on how to turn up the pump at this point. If so, you'll know the signs of 'tampering', broken paint, cover off the apc, collar broke off the full load screw, etc.

If you had to have your foot to the floor to pull, then 7-8mpg is probably pretty fair. Incidentally, I've never towed with a gas truck of any brand that could hold a candle to these trucks

Making 25psi of boost sounds consistant with having the 16cm^2 housing on the truck with a ~10% increase in pump flow.

Is this an auto or 5spd? IMO the autos, for the most part, feel much weaker than the sticks.

Even though I love the 1st gen trucks, one needs to remember, in their near stock form, they are FAR short of the diesel trucks that have been make in the last 5 yrs in regards to power.

Lil Dog

If it feels boggy and runs hot I would guess that the timing is not up to spec. Retarded timing would bump your EGT's and engine temps with nothing to show for it at the wheels.

Maybe a tuneup is in order to ensure you are getting the most out of what you already have. This includes, valve set, fuel pressure check and timing adjustment(if required).

Start with fresh "as new" settings and you can go from there.

J-eh

Bushy

Hi Steve,

Yup, Lil Dog is right on.... first check the current settings, condition of and etc. From there, replace all your filters especially the fuel filter as it gets ignored a little too much.
Once you know were your timing is NOW then adjust as needed... set at roughly 1.50mm or 15-16*advance. This will help compensate for uprated injectors in general as well as "stock nozzles but pump turned up too..."

Confirm your coolant level and operation of the thermostat, even a new one can go fubar on you....
Your boost tells us that you have had some sort of uprating/ugrades done. It could be injectors (won't know for sure unless you pull them out and check numbers) injection pump tuning/alteration or combination of those.

It would help to know a bit more as well,... for example what are your EGT's like, what RPM's are talking about here in 3rd (one to one ratio) and or in OD which I think is .67:1 ratio
Each will result in different temps (both EGTand water) based on loading, throttle position etc. ( this is were we point out the need to have some basic gauges)
What is your idle speed and quality, is it smoky/hazy, or clean with no white or whitish blue haze??
If you are overworking the engine and tranny due to misadjustment or improper adjustment you can expect those types of problems..as well as others...
With a properly tuned engine/tranny/pump you could reasonable expect 15-18mpg with near max safe EGT's. Maybe a bit of plus or minus, but in that range, which includes "driving style" factors.

Hope that helps.

Bob.

apache

My 93 when I purchased it used with 72k ran like a freight train, and got 19mpg, the pump cratered and the shop that rebuilt it said that it would have a 10/15% power gain. now its very doggy compared to before but gets 20+ mpg, it will do 100 mph+. man I miss the power it had but Im a tight wad and the milage is nice. fuel is 1.90 a gallon here still. Sounds like some pump adjustments will do a world of good for you. The temp guage will reach 3/4 up and this is considered normal range. Good luck.

Lil Dog

Turbocharged diesels are not like gas engines. More power doesn't always mean less mileage. In some cases, depending on the modifications, you get better mileage.

The Turbo'd diesels only use the fuel they need to do the job. If you have a 400 hp truck, you still only need the 100-130 hp to fly down the highway and you will only use the fuel required to do that. I know guys with 500 hp and still get 20+ MPG..

J-eh

DodgeCowboy

Ok I done some reaserch for ya. Here it goes plastic throttle rod ends fail, resulting in sloppy throttle or no throttle response. Throttle rod end at the front of the injector pump. The original plastic rod ends eventually weaken and fall off the ballstuds. Replacement sockets are metal and should be much more reliable. Could this be why your might not getting any throttle response?

http://www.dodgeram.org/tech/dsl/tro...ting/t-rod.htm

Redleg

[quote author=DodgeCowboy83 link=board=9;threadid=19367;start=0#msg182908 date=1063172939]
Ok I done some reaserch for ya. Here it goes plastic throttle rod ends fail, resulting in sloppy throttle or no throttle response. Throttle rod end at the front of the injector pump. The original plastic rod ends eventually weaken and fall off the ballstuds. Replacement sockets are metal and should be much more reliable. Could this be why your might not getting any throttle response?

http://www.dodgeram.org/tech/dsl/tro...ting/t-rod.htm
[/quote]
Good point. I still have the plastic myself, but adjusted the linkage to take up all the play. You may also have to take up any slop in the throttle cable. I had quite a bit, took out the slack at the pedal. A new cable was about $65 from Cummins and would probably stretch right back out. This did help throttle response.

Redleg

Also, do you have any record indicating when the valve-lash may have been checked? If not, it might be worth it to just get it out of the way and have peace-of-mind. Might bring back some performance.

furious70

ah, good point on the slack in the cable, I forgot about my truck also having that problem when I got it, I was missing about 1" of air tween the pedal and floor!

in very near stock form (when I got it) my truck got 19mpg @ 75mph empty. With the turbine swap and the pump tinkered with I'm at 22mpg. I usually get 20mpg commuting in Chicago now....it's not too bad