My truck is way down on power. It really feels like it does when there's no boost. No odd smoke of any kind. Relatively new IP, Bosch injectors and lift pump, and boost control solenoid. Threw P0236 code, yet I have 20' of vacuum at idle at the wastegate actuator. What am I missing?
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Down on power
- Thread starter alfadoc
- Start date
When the "new" IP was installed did anyone check things with a tech 2 scanner?
Will L.
Well-Known Member
Do you have a boost gauge on it? Is boost normal? Obstructed air filter/intake?
Get clear tubing on the 1/4” return out the front of the ip (injection pump) Watch for bubbles and or contamination. Hardware store sell clear pvc tube by thr foot that will last a few years. Get screw style hose clamps with it, it is thicker than the factory line so the squeeze type won’t work. Permanent clear fuel line available here: fuel-line.com Best to leave clear on this location permanently For future quick diagnostics.
Get a metal adapter to tap fuel pressure reading at the ip inlet of the ip
Others here know the size.
Best answer is leave this permanently in place and install a gauge in the dash so you see it while driving. Low fuel pressure coming in wears out the ip amazingly fast. Seen brand new units ruined in no time. Proper pressure according to Stanandyne (ip mfr) is 8-14 psi. New factory pump barely hits the minimum, AC Delco EP158 is the best of them and barely good for a couple years on ds4.
4-8 psi will start and run fine. Under 4 psi you will feel power loss, and minimal damage is occurring in the ip. Get under 1psi and major wear is occurring and bigger power loss noted. Problem is driving truck daily you don’t notice the tiny power drops as it goes down slowly like tires wearing out. Just one day people notice it’s time for new ones. No one notices 40% worn. Side track not causing problems- make sure you are adding Stanandyne fuel lubricant additives or 2 stroke oil. None of the stuff for modern common rail fuel systems- that stuff does damage to these. Don’t bother until you have the current problem solved.
You didn’t mention any codes-
GM training was get the clear line and pressure readings, then check air filter as first 3 steps…
Get clear tubing on the 1/4” return out the front of the ip (injection pump) Watch for bubbles and or contamination. Hardware store sell clear pvc tube by thr foot that will last a few years. Get screw style hose clamps with it, it is thicker than the factory line so the squeeze type won’t work. Permanent clear fuel line available here: fuel-line.com Best to leave clear on this location permanently For future quick diagnostics.
Get a metal adapter to tap fuel pressure reading at the ip inlet of the ip
Others here know the size.
Best answer is leave this permanently in place and install a gauge in the dash so you see it while driving. Low fuel pressure coming in wears out the ip amazingly fast. Seen brand new units ruined in no time. Proper pressure according to Stanandyne (ip mfr) is 8-14 psi. New factory pump barely hits the minimum, AC Delco EP158 is the best of them and barely good for a couple years on ds4.
4-8 psi will start and run fine. Under 4 psi you will feel power loss, and minimal damage is occurring in the ip. Get under 1psi and major wear is occurring and bigger power loss noted. Problem is driving truck daily you don’t notice the tiny power drops as it goes down slowly like tires wearing out. Just one day people notice it’s time for new ones. No one notices 40% worn. Side track not causing problems- make sure you are adding Stanandyne fuel lubricant additives or 2 stroke oil. None of the stuff for modern common rail fuel systems- that stuff does damage to these. Don’t bother until you have the current problem solved.
You didn’t mention any codes-
GM training was get the clear line and pressure readings, then check air filter as first 3 steps…
I do not have a boost gauge on it yet. I have the gauges for boost, EGT and trans temp, just haven’t had time to install yet.
I have Tygon line installed at the IP return and injector return lines. No bubbles.
I did mention P0236. That part of what’s baffling. Feels like no boost, but there’s good vacuum at the actuator at idle,
I use the Standyne lubricity formula in every tank.
I have had this truck for 15 years. Most troubles that a 6.5 can give you, I’ve experienced and solved. This one has my scratching my head.
I have Tygon line installed at the IP return and injector return lines. No bubbles.
I did mention P0236. That part of what’s baffling. Feels like no boost, but there’s good vacuum at the actuator at idle,
I use the Standyne lubricity formula in every tank.
I have had this truck for 15 years. Most troubles that a 6.5 can give you, I’ve experienced and solved. This one has my scratching my head.
Will L.
Well-Known Member
Oh shoot! I’m sorry, skipped right over that somehow.
So get a vacuum gauge and verify what the computer is seeing is actual.
Worn vacuum pump is less common than leaking vacuum lines. More rare yet is the temp sensor up front being off and confusing the computer.
Are you getting black smoke when accelerating hard?
Watergate moves properly?
Use hand vacuum pump to operate wastegate swing.
So get a vacuum gauge and verify what the computer is seeing is actual.
Worn vacuum pump is less common than leaking vacuum lines. More rare yet is the temp sensor up front being off and confusing the computer.
Are you getting black smoke when accelerating hard?
Watergate moves properly?
Use hand vacuum pump to operate wastegate swing.
I can hear the turbo whistle as normal. Air filter is not pristine, but probably has less than 20,000 miles on it. Wastegate lever moves freely. I can’t move it by hand when the truck is idling. No black smoke when accelerating hard. Approximately 20” of vacuum at actuator at idle.
ak diesel driver
6.5 driver
Pretty rare but waste gate flapper can become unattached from rod
dbrannon79
I'm getting there!
With the engine idling reach down and grab the turbo actuator rod and try to move it. with the engine at idle you should not be able to move the rod by hand. you might have a failing wastegate solenoid. back when I was replacing all the vacuum lines on my truck I accidentally connected the wastegate solenoid backwards which resulted in no boost and hardly any power. if you or someone has been in there you might double check this.
if not and this issue just came about, if you can move the actuator rod by hand with the engine running, check vacuum lines from the actuator back to the solenoid and then to the vacuum pump. if all is good, then it will be ether a bad diaphragm in the actuator or the solenoid.
if not and this issue just came about, if you can move the actuator rod by hand with the engine running, check vacuum lines from the actuator back to the solenoid and then to the vacuum pump. if all is good, then it will be ether a bad diaphragm in the actuator or the solenoid.
Will L.
Well-Known Member
Because the computer is doing all the actual control, you need to verify what it sees with reality. Vacuum and boost.
You need to know what the fuel pressure is right at the inlet of the ip while under load. This is a super common issue with multiple possibilities. I know of 5 times people have replaced an ip and later found simple damaged fuel line. This is why I am adamant people follow Stanandyne’s diagnostic method of the fitting screwing into the ip directly. Thats the reason they demanded it from GM after different dealerships wanting to warranty good units.
It sounds like the turbo is working with no smoke, but verified boost numbers are required. Do you have a boost fooler and bumped boost- multiple ways to do so we need to know how if so.
You need to know what the fuel pressure is right at the inlet of the ip while under load. This is a super common issue with multiple possibilities. I know of 5 times people have replaced an ip and later found simple damaged fuel line. This is why I am adamant people follow Stanandyne’s diagnostic method of the fitting screwing into the ip directly. Thats the reason they demanded it from GM after different dealerships wanting to warranty good units.
It sounds like the turbo is working with no smoke, but verified boost numbers are required. Do you have a boost fooler and bumped boost- multiple ways to do so we need to know how if so.
Agreed 100%. I really can’t go any farther down the diagnostic path without knowing these numbers, and I’ve never been an advocate of blindly throwing parts at a problem, hoping something will work. No, I do not have a boost fooler or any other modification other than the PMD in the grill and the exhaust. I’ll get the gauges hooked up and report back. Thank you Will.
Come on over to The Darkside. We have coffee!
Even a modern Gasoline engine will do a better job than the vintage pickup you have now. Ride in a new 400+HP 1000+ Ft LB Cummins and I bet this truck gets Farm Duty.
Cummins is proud of their parts and RAM, although improved, is not known for good electrical. It's a Cummins in a Dodge RAM wrapper. At least it's not a disposable light duty diesel that GM can't get away from.
Meanwhile you are on the proper path to fix yours.
If you do come over to the Darkside buy NEW. Used prices are out of sight. May as well get a warranty, lemon law protection, and something that someone else hasn't beat and put away wet. Even if you decide to go with a gas engine to save money: new is a better choice.
No way I can afford a newer truck, and I have a particular soft spot for the one I have. I’ve also just completed a full, bare metal body restoration on this one. Getting it to run right is the only option.
royunion
Active Member
I would bet bad fuel and weak lift pump. That which you describe is what mine did. Even weak lift pump and algae.
But first has anyone done the KOKO procedure to set the timing.???
There is a PC program that can read the timing - the name eludes me right now
It could also be a leaking or melted vacuum line. See also my post at https://www.thetruckstop.us/forum/threads/6-5-turbo-issues.52013/post-679515
But first has anyone done the KOKO procedure to set the timing.???
There is a PC program that can read the timing - the name eludes me right now
It could also be a leaking or melted vacuum line. See also my post at https://www.thetruckstop.us/forum/threads/6-5-turbo-issues.52013/post-679515
Lift pump was fairly new, but an aftermarket. The IP timing was set with a Snap On scanner.
I’ve just installed an AC Delco lift pump, the one for a ‘93. Also swapped out fuel filter, which wasn’t terribly old, but it didn’t look great, and had fine metal particles in it. It may be running better. I’ll know when I get the camper loaded back on the truck.
I’ve just installed an AC Delco lift pump, the one for a ‘93. Also swapped out fuel filter, which wasn’t terribly old, but it didn’t look great, and had fine metal particles in it. It may be running better. I’ll know when I get the camper loaded back on the truck.
royunion
Active Member
Even NEW the OEM solenoid pumps are worthless usually now-a days
The engine can be gotten running with even bad timing. A KOKO procedure is needed to to relearn everything and set timing. It took my engine from - 75 crappy doggish to - 1.25 way better running and instant starting.
Lots of people say they put on a new lift pump only to eventually find out that as told - the OEM pumps are junk
I use the Sure Cure Lift Pump which is regulated to 20 pre filter and hits the IP at 15 to 18.
Almost all 6.5 problems surround reliable regulated decent fuel pressure
See my posts mentioned previously
The engine can be gotten running with even bad timing. A KOKO procedure is needed to to relearn everything and set timing. It took my engine from - 75 crappy doggish to - 1.25 way better running and instant starting.
Lots of people say they put on a new lift pump only to eventually find out that as told - the OEM pumps are junk
I use the Sure Cure Lift Pump which is regulated to 20 pre filter and hits the IP at 15 to 18.
Almost all 6.5 problems surround reliable regulated decent fuel pressure
See my posts mentioned previously