Engine/Transmission (1994 - 1998) Help me tune the 12v in my Hummer H1

[IndyBoy]

Hi Have a Hummer H1 with a Ppump 12v.
I'll list off the issues it has and the ideal changes i'd like to get to. any help would be appreciated.

Problems to overcome:
1. hard cold starts: currently there isnt a heater grid (if anyone has a grid, wiring and solenoids, let me know, i'm interested). At 50*F it struggles to start. my 4bt skid steer seems to start much easier at the same temps.
2. Smokes lots when cold. Big old puff of white smoke when she fires up. Still smokes more than i'd like once warmed up.
3. Doesn't seem as powerful as i'd expect, especially seems to give up at higher RPM (over 2K). ( I have a 24v vp44 ram 3500 as my only comparison)

Few points of interest:
1. unknown engine origin. I'm suspecting industrial, it had yellow paint and seems tuned to low rpm. previous owner had to change the governor springs because it wouldn't go over 2200 rpm.
2. No engine id plate. are there any castings to identify the motor?

What I would like to get out of it:
1. Easier starts. Heater grid of course. Assuming injector timing and injectors could have something to do with this.
2. Less unburnt fuel/white smoke. (would like low smoke in general)
3. More Power. Here i'm looking for a Daily Driver setup that wont completely destroy my transmission. (fresh 47rh, not sure if its built or not). I'm thinking 250-350hp and 500-700 torque (I know this is over the 47rh ratings)
4. Less noise - thing is already too loud. I do not want a setup that adds a single decibel. its past any point of cool.

Bottom line question:
What is an injector, timing, fuel plate, etc that would balance my issues and my goals?

 

[Wayne M.]

Sounds like you have a timing issue, judging by your smoke comments. Should start down to single digit with out a shrug.
If it is an industrial spec engine, you may be able to put an ether start kit. These work real well if used properly, and that would be only if it's real cold.
I think you need to do a full time and tune, then see where everything else is at.

Please post some pictures of your rig- love to see the install in the H1. I thought they only came with GM V8's.

 

[The patriot]

My truck ran like that when my lift pump was going.
You know....you should add some gauges to help diagnose problems.....
fuel pressure and pyrometer minimum....

 

[IndyBoy]

It has a pyrometer, but not fuel pressure (my truck is a vp44,,, so its got fuel pressure and a low pressure light).
The Hummer has a pretty new AirDog pump, so i doubt that is it.

I'll check the timing over the next couple weeks when i get some time. Attaching some pics.

 

[Wayne M.]

Now that's cool.
The engine is really stuffed in there! I hope there's access on the inside. I wasn't sure if the cowl height was enough. I've seen different H1's out there and they have different wheels. Does your H1 have the drop boxes in the knuckles?

Good luck finding your issue.

 

[IndyBoy]

Yea, it has the drop box (portal gears). 2 inch body lift allows a cummins to fit with some modifications to the inner dog house. Beleive it or not, the engine (front, rear, and both sides its crazy accessible compared to working out of the dodge.
I've ordered the tools for checking/setting the timing.

 

[AEdelheit]

Very cool setup but I have to ask, why no hose clamps on the intake tubing?

 

[The patriot]

Very cool setup but I have to ask, why no hose clamps on the intake tubing?

Or air filter....

 

[GAmes]

I agree on the timing check. Nothing will make a 12 valve quieter, forget that. If the auto is stock I wouldn't advise any HP upgrades. It will fail soon enough, then you can get it built and add some power. Having an operational fuel pump isn't all a fuel pressure gauge will tell you. Pressure is caused by the restriction of the overflow valve. If the valve isn't up to spec it will cause hard starting and low power. There are several vendors, but basically your choices are a stock one https://www.genosgarage.com/product/2-417-413-101-kit/fuel-system-accessories-replacement-parts or one from torq tek http://www.torkteknology.com/details-of-each-Tork-Tek-Overflow-Valve/

 

[Wayne M.]

Very cool setup but I have to ask, why no hose clamps on the intake tubing?

Very true good question. If there were leaks, it'd sound like a big fart fest. Our Macks break I/C clamps and that's what it sounds like.

IndyBoy, thanks for sharing the mods. Good luck with checking the basics, and make sure the basics are covered- like boost leaks.

 

[IndyBoy]

That pic was from while installing the intercooler. there are clamps now

 

[JR]

Did you do the conversion? Way cool!

Only way to reduce noise is insulation blankets, and acoustic mats. Aside from that, enjoy the sound!

I agree with checking the timing. I can't tell you how many industrial 4bt's and 6bt's I've operated with no cold start aids that fire relatively easy down to 0*F. Grid heaters were installed for emissions purposes only.

 

[IndyBoy]

fyi, here is what i know about the transmission. does anyone know about suncoast? I'm trying to guestimate what the trans should be good for.

47RH
Dacco Triple Lock Converter
Billit Input
Suncoast Heavy Hauller kit
Billet Servos
Billet Kickdown
Billet Bands

 

[The patriot]

Mine's a stick, but what I gather the auto's are VERY marginal as soon as you turn it up....even a little.
If you have 75K or more on the trans, it'll be soon.

 

[DonFitzwater]

That trans should handle some decent power upgrades from the list you provided.

 

[DieselRyan]

Check on the top side of the oil cooler on the block. An ESN should be stamped there. Let me know what the number is if you can find it.

 

[GAmes]

Check on the top side of the oil cooler on the block. An ESN should be stamped there. Let me know what the number is if you can find it.

Not true on 12 valves. The ESN is on a tag that is affixed to the side of the gear case, near the throttle linkage.

 

[DieselRyan]

Not true on 12 valves. The ESN is on a tag that is affixed to the side of the gear case, near the throttle linkage.

I know this. But he said that he no tag for the ESN. This is an alternative location if the Dataplate is missing.

 

[GAmes]

I've disassembled 3 12 valves. None had a SN stamped into the block. I have read that that started with the over valved engines.

 

[DieselRyan]

I've disassembled 3 12 valves. None had a SN stamped into the block. I have read that that started with the over valved engines.

I stand corrected. I looked one of my 12 valve engines and I didn't have the serial number there. I believe it was the 24 valves that started this. I'm a technician at Cummins. With all the engines we have sometimes you forget some things.