some sobering realitys

[bison]

I finally finished putting all gauges in my 98 today,

i put in a new LP.read a whopping 2.5 psi max press at idle and with engine off 4.Got 1/2 lb cruising Gawd.
That sucksIt was a spare, bought 1 1/5 yr ago.( no warranty left)And yes ,new tank,new filter,new everything.Now i have to dive under there to change that LP again.

pyro goes to 1100 degree in a heartbeat when i step on it,thereby the turbo gave me only 6 psi, at 2500 rpm, and this is empty and on flat ground . Next week i got to pull a 7000 lb trailer a 1000 km trough some pretty steep hills,makes me shudder what that is gonna be like.This is gonna suck.
Cat is gone,and i cut the restrictions outa the stock down pipe and welded some other pieces in.

 

[Matt Bachand]

TM dropped my EGT's a ton by granting more boost.

Buy a new LP, and return the defective one saying it was the one you just bought.

 

[Pillow]

I cannot emphasize this enough... Get the Heath HO pump!!! It is sooo worth it.

Also I have had good luck with the AC Delco LP from the dealer. Really not much difference in price than the online places. I was in a pinch for the Suburban... And it is actually fast!

The Carter I got from SSD was a POS and I replaced it with the Heath HO... And I still need more fuel I cannot burn it down which means I am running out of fuel. But I can get it hot on steep long grades, but then I use the gauges to drive at 900F or 13PSI. At that point you need to keep your eye on the coolant temp. Flatland I can run all out all day.

Chip it and rock and roll

 

[bison]

I cannot emphasize this enough... Get the Heath HO pump!!! It is sooo worth it.

Also I have had good luck with the AC Delco LP from the dealer. Really not much difference in price than the online places. I was in a pinch for the Suburban... And it is actually fast!

The Carter I got from SSD was a POS and I replaced it with the Heath HO... And I still need more fuel I cannot burn it down which means I am running out of fuel. But I can get it hot on steep long grades, but then I use the gauges to drive at 900F or 13PSI. At that point you need to keep your eye on the coolant temp. Flatland I can run all out all day.

Chip it and rock and roll

all these things cost money,i dont have right now.:nonod:besides ,bill aint that cheap,add the dollar exchange and freight.

The LP was an AC delco. got a carter on it now,pumps out 10 psi engine off,thats more to my liking.

 

[buddy]

Is that with vacuum setup or TM?

Try putting vac pump line straight to wastegate actuator. That works really well for power and PCM cant do a damn thing about it. If it codes it could defuel I guess but that when you add the cheap resistor boost fooler if not already reflashed PCM.

Get a LP from a 93 from the parts store, or get a good aftermarket one and adapt the lines.

 

[bison]

Is that with vacuum setup or TM?

Try putting vac pump line straight to wastegate actuator. That works really well for power and PCM cant do a damn thing about it. If it codes it could defuel I guess but that when you add the cheap resistor boost fooler if not already reflashed PCM.

Get a LP from a 93 from the parts store, or get a good aftermarket one and adapt the lines.

still vac, just tested it at 24 hg at idle.

I'm gonna try rigging up a TM tomorrow.I need to get the EGT's down, i cant pull a 1000 km with the vac pump straight to the wastegate?can i?

LP from 93, thats what i swapped in tonight.

 

[buddy]

Well you can run 1000km with vac pump straight to wastegate, especially if only running stock PCM. Its basically just always closed wastegate, and will get you like 12psi boost, which is why youll need boost fooler with stock PCM. A spring loaded one would be better, but not much different except dump some boost while cruising highway.

Have you verified the boost guage is accurate to what AE says while driving?

 

[Matt Bachand]

IIRC after I installed my boost gauge last year I WOT a few times to watch the boost, and I got it to defuel around 12psi. I don't think you can build enough boost to hurt your engine with stock 'puter. It should defuel.

I'd build a mechanical spring one as you said, defueling could become extremely annoying to the point of un-driveable half way to your target if you find a steep grade.

 

[buddy]

Thats what the boost fooler is for, to stop defueling. And its a simple cheap install.

 

[Matt Bachand]

Thats what the boost fooler is for, to stop defueling. And its a simple cheap install.

Yes, but if W/G Tied/forced shut and you bypass the boost fooler you risk headgaskets or worse by overboost.

That would ruin your day far away from home.

 

[buddy]

Thats why the guages are so important, and on stock PCM, I dont think it will be an issue.

 

[Turbine Doc]

Thats why the guages are so important, and on stock PCM, I dont think it will be an issue.

X2

even fooled for boost level, IAT protection should still be in play, and max fuel rate will limited to 56 (s) and 63 (F)mm ^3/1000 in stock PCM so you aren't going to build tons of boost anyway,

but it does bear vigillence, as when boost goes up, so does backpressure & EGT, couple in high IAT from high boosting then you can also get high coolant, it's cumulative, but manageable with gauges in the short term, you would not want to run forever with WG fully gagged shut, best to have some sort of boost control when using a GM turbo

 

[DieselCash]

This is one of the main reasons the first three mods on my truck are going to a a fuel pressure gauge, EGT gauge, and a boost gauge. Even thou I have been drooling :drool5: all over a 4" exhaust system for almost a year.

I am glad you posted this, maybe it will help other realize how important gauges are on these Diesel motors.

Thanks! :thumbsup:

 

[SnowDrift]

Low fuel pressure

I finally finished putting all gauges in my 98 today,

i put in a new LP.read a whopping 2.5 psi max press at idle and with engine off 4.Got 1/2 lb cruising Gawd.
That sucksIt was a spare, bought 1 1/5 yr ago.( no warranty left)And yes ,new tank,new filter,new everything.Now i have to dive under there to change that LP again.

pyro goes to 1100 degree in a heartbeat when i step on it,thereby the turbo gave me only 6 psi, at 2500 rpm, and this is empty and on flat ground . Next week i got to pull a 7000 lb trailer a 1000 km trough some pretty steep hills,makes me shudder what that is gonna be like.This is gonna suck.
Cat is gone,and i cut the restrictions outa the stock down pipe and welded some other pieces in.

don't write it off just yet. How does it RUN, even though the fuel pressure is low? By everything Heath says, GM says and everyone that knows 6.5s, mine should have been a piece of crap for the first several years I had it. No disrespect intended toward anyone, either - It's just that NO ONE could figure it out. I had 3 psi at idle, then if I accelerated slow to pull out of the driveway, the pressure dropped immediately to zero. Three different Delphi LPs and lots of headaches didn't cure it. The same LP on another truck would give a full 7 psi at idle.

BUT, the truck ran like a perfect. With a new IP as of last fall, I suspect the return fuel rate was too high on the last pump and had been that way since day one for the previous pump. New IP shows normal pressures.

There is a set screw in the pump some place that determines return fuel rate. Apparently, this can cause the low pressure symptom.

 

[Matt Bachand]

This is one of the main reasons the first three mods on my truck are going to a a fuel pressure gauge, EGT gauge, and a boost gauge. Even thou I have been drooling :drool5: all over a 4" exhaust system for almost a year.

I am glad you posted this, maybe it will help other realize how important gauges are on these Diesel motors.

Thanks! :thumbsup:

I've been drooling for new exhaust for 3 years... Went 2 yeaers before my first mods. and they were guages too.

I don't regret it.

 

[bison]

don't write it off just yet. How does it RUN, even though the fuel pressure is low? By everything Heath says, GM says and everyone that knows 6.5s, mine should have been a piece of crap for the first several years I had it. No disrespect intended toward anyone, either - It's just that NO ONE could figure it out. I had 3 psi at idle, then if I accelerated slow to pull out of the driveway, the pressure dropped immediately to zero. Three different Delphi LPs and lots of headaches didn't cure it. The same LP on another truck would give a full 7 psi at idle.

BUT, the truck ran like a perfect. With a new IP as of last fall, I suspect the return fuel rate was too high on the last pump and had been that way since day one for the previous pump. New IP shows normal pressures.

There is a set screw in the pump some place that determines return fuel rate. Apparently, this can cause the low pressure symptom.

In your case,it could have been a faulty return orifice, but IMO any IP running at 0 psi LP press is gonna shorten its life drasticly,never mind engine performance.

 

[Matt Bachand]

don't write it off just yet. How does it RUN, even though the fuel pressure is low? By everything Heath says, GM says and everyone that knows 6.5s, mine should have been a piece of crap for the first several years I had it. No disrespect intended toward anyone, either - It's just that NO ONE could figure it out. I had 3 psi at idle, then if I accelerated slow to pull out of the driveway, the pressure dropped immediately to zero. Three different Delphi LPs and lots of headaches didn't cure it. The same LP on another truck would give a full 7 psi at idle.

BUT, the truck ran like a perfect. With a new IP as of last fall, I suspect the return fuel rate was too high on the last pump and had been that way since day one for the previous pump. New IP shows normal pressures.

There is a set screw in the pump some place that determines return fuel rate. Apparently, this can cause the low pressure symptom.

Give-away should have been 8-10psi at wait to start, instantly dropping to 3psi at idle, and immediately 0 on any acc pedal movement...

Hind-sight is always 20/20 though...

 

[buddy]

Is there an accessable return adjustment?

 

[bison]

I think the bypass is calibrated by a certain size steel wire ( varies per pump)trough a bore,restricting flow.
Could have been forgotten in snowdrift's IP.

 

[bison]

Got the TM build and installed, but need to adjust it yet and see how it works.