Still no Boost

[FoMoCo]

I just replaced the injectors with Stanadyne G codes that were pop tested, rebuilt IP, new o-rings, caps and return line. Clean Air filter, fuel filter has less than 1,000 miles on it. The truck has been timed and is at 10 degrees. I can only get maybe 3 lbs of boost if I nail it in top gear. Lots of black smoke for a bit and it clears. The truck has a ATS turbo upgrade with the intercooler. I modified the boost controller and when I had boost, it would hit 11 lbs no problem. What should I do first?

 

['94IDITurbo7.3]

So you did your fuel system stuff. were you getting 11psi after that, then played with the wastegate and now only getting 3psi?

 

[kc0stp]

back the timing off to start with, then start checking for boost leaks (and double check boost gauge works)

 

[FoMoCo]

back the timing off to start with, then start checking for boost leaks (and double check boost gauge works)

Back the timing OFF, everybody said to increase it for today's new diesel. I have it marked with a lower timing setting, what should I lower it to?

I was loosing boost before the fuel repairs, I thought more fuel would increase the boost. Will check for leaks again but doubt it, I had some on the air to air cooler that was fixed with epoxy, and will check the clamps (which have broke before) but all that has been gone over during the IP and injector replacement.

How do you check the boost controller, for proper operation?

 

[FoMoCo]

So you did your fuel system stuff. were you getting 11psi after that, then played with the wastegate and now only getting 3psi?

I was getting 11 psi of boost, than I had some fuel problems and changed out the fuel system and thought the boost would come back up. I had reduced boost before all the fuel parts, but not this bad. Must be a leak some where or the motor is bad

 

[kc0stp]

8-9 for timing at your altitude (7.5 up here at most) as far as checking the gauge just put a known/regulated supply of air to the line feeding the boost gauge, biggest challenge is getting a decent seal and low enough pressure.

 

[icanfixall]

Please leave the the timing where it is for now. Thats not your problem. You have a leak somewhere. It can be an intake leak or and exhaust leak. Either one will kill the boost. A stuck wastegate valve will also cause a boost problem. Look over all the exhaust joints. If any have soot around or near them thats a leak. Any oil from the intake area joints is an inlet leak.

 

[Wyreth]

X2 on not touching the timing.

retarding the timing will cause the turbo to spool faster and higher, but that's because more of the combustion is happening in the exhost. Rather than in the cylinder where we want it to. So yea, you can pull your timing back, get some better boost numbers, and less power.

How many miles are on the turbo, and what are your EGT's looking like? What were they like before the fuel system replacement?

 

[FORDF250HDXLT]

Back the timing OFF, everybody said to increase it for today's new diesel.

not everyone says that.
im seeing my best performance and economy @ 7 BTDC.

still,i agree your overly advanced engine timing isn't your issue at hand.

 

[FoMoCo]

EGT's look good just under 300 going down the road, nothing above 600. The low boost is keeping my egt's low. The turbo is factory but I had it inspected when I did the ATS turbo housing upgrade, which has been a few years but not that many miles.

 

[kc0stp]

Umm low boost should cause the opposite, lower boost = richer fuel/air = hotter EGTs/more smoke

 

[Wyreth]

Well, I still agree with Gary, you've probably got a leak, either boost or exhost. Also kc0stp is right. Boost lowers egt. Not the other way around. Wait till you see n/a egt numbers, they're scary.

With numbers that low, I am gunna bet your rebuild was tuned for a n/a, and part of the problem is you simply need more fuel. Try turning the pump up two flats and see what that does.

 

[FoMoCo]

Like you said, must be the gauge. I will start there. The truck runs good just the acceleration is not good in top gear, but it never has been

 

['94IDITurbo7.3]

EGT's look good just under 300 going down the road, nothing above 600.

Two things here...either you have a junk pyro or you have a junk injection pump that is not putting out any fuel. With that said, seeing that you had good boost before the pump swap(at least before the old pump died) and now you have next to nothing for boost i would say you have a junk IP.

Where did you get your injection pump from if you don't mind? Injectors came from ??? as well.

 

[Black dawg]

not everyone says that.
im seeing my best performance and economy @ 7 BTDC.

still,i agree your overly advanced engine timing isn't your issue at hand.

Yea, With a turbo truck with lots of fuel rate, I like about 5 BTDC.
10 degrees would make my truck a smoky, rattly, rolling road block.