STD Maintenance General Poo. Car is having hesitation on accel mid rpm/boost range.

Poo. Car is having hesitation on accel mid rpm/boost range.

Poo. Car is having hesitation on accel mid rpm/boost range.

 
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winmutt
bitbanger

3,468
07-09-2010, 09:37 AM #1
Gonna look at the filters when I get out of work today. The fact that its just a pulse of loss is worrying. Almost like it could be drivetrain as well.

1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42
winmutt
07-09-2010, 09:37 AM #1

Gonna look at the filters when I get out of work today. The fact that its just a pulse of loss is worrying. Almost like it could be drivetrain as well.


1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42

Captain America
Boostin' & Roostin'

2,221
07-09-2010, 10:15 AM #2
Pulse of loss? Like just briefly and then power comes back? Mine is doing that but I know its a fuel starvation issue....


1982 300D Turbo ... 3,6xxlbs, No fan, No AC, Hood Stack, No ALDA, No rear bumper and stuffed front, A/W Intercooled, Injectors by Greezer and HUGE Pre-Chambers with help from OM616 & Simpler=Better, Fuel Cranked up, 60 Trim Compressor wheel, EGT, EMP, Boost 50" Rigid Radius bar on roof Aux tank for a total of 48 Gal Of Diesel! Odyssey PC-1750 Battery in trunk, 27"x8.5"/R14 Maxxis BigHorn Mud Terrains, In June '14 issue of Off Road Mag

AX15 Jeep Trans swap in progress....

Captain America
07-09-2010, 10:15 AM #2

Pulse of loss? Like just briefly and then power comes back? Mine is doing that but I know its a fuel starvation issue....



1982 300D Turbo ... 3,6xxlbs, No fan, No AC, Hood Stack, No ALDA, No rear bumper and stuffed front, A/W Intercooled, Injectors by Greezer and HUGE Pre-Chambers with help from OM616 & Simpler=Better, Fuel Cranked up, 60 Trim Compressor wheel, EGT, EMP, Boost 50" Rigid Radius bar on roof Aux tank for a total of 48 Gal Of Diesel! Odyssey PC-1750 Battery in trunk, 27"x8.5"/R14 Maxxis BigHorn Mud Terrains, In June '14 issue of Off Road Mag

AX15 Jeep Trans swap in progress....

winmutt
bitbanger

3,468
07-09-2010, 01:16 PM #3
(07-09-2010, 10:15 AM)Captain America Pulse of loss? Like just briefly and then power comes back? Mine is doing that but I know its a fuel starvation issue....

Yep pretty much. Guessing filters or air in the line.

1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42
winmutt
07-09-2010, 01:16 PM #3

(07-09-2010, 10:15 AM)Captain America Pulse of loss? Like just briefly and then power comes back? Mine is doing that but I know its a fuel starvation issue....

Yep pretty much. Guessing filters or air in the line.


1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42

Captain America
Boostin' & Roostin'

2,221
07-09-2010, 01:48 PM #4
There should only be air in the line if there were some sort of restriction somewhere. Air would "appear" right after the restriction from the vacuum produced at that point then travel all the way up to the fuel pump.

I've got something similar going on... I don't drive the car WOT ever because I don't have a pyrometer yet but I will mash the peddle for a couple seconds at a time on the freeway every once in a while and when I do boost comes up, flattens, drops off, then comes back up... all within a couple second time.

Gotta be fuel I'm thinking, you and me.

I want to put a fuel pressure gauge inline after the lift pump to verify


1982 300D Turbo ... 3,6xxlbs, No fan, No AC, Hood Stack, No ALDA, No rear bumper and stuffed front, A/W Intercooled, Injectors by Greezer and HUGE Pre-Chambers with help from OM616 & Simpler=Better, Fuel Cranked up, 60 Trim Compressor wheel, EGT, EMP, Boost 50" Rigid Radius bar on roof Aux tank for a total of 48 Gal Of Diesel! Odyssey PC-1750 Battery in trunk, 27"x8.5"/R14 Maxxis BigHorn Mud Terrains, In June '14 issue of Off Road Mag

AX15 Jeep Trans swap in progress....

Captain America
07-09-2010, 01:48 PM #4

There should only be air in the line if there were some sort of restriction somewhere. Air would "appear" right after the restriction from the vacuum produced at that point then travel all the way up to the fuel pump.

I've got something similar going on... I don't drive the car WOT ever because I don't have a pyrometer yet but I will mash the peddle for a couple seconds at a time on the freeway every once in a while and when I do boost comes up, flattens, drops off, then comes back up... all within a couple second time.

Gotta be fuel I'm thinking, you and me.

I want to put a fuel pressure gauge inline after the lift pump to verify



1982 300D Turbo ... 3,6xxlbs, No fan, No AC, Hood Stack, No ALDA, No rear bumper and stuffed front, A/W Intercooled, Injectors by Greezer and HUGE Pre-Chambers with help from OM616 & Simpler=Better, Fuel Cranked up, 60 Trim Compressor wheel, EGT, EMP, Boost 50" Rigid Radius bar on roof Aux tank for a total of 48 Gal Of Diesel! Odyssey PC-1750 Battery in trunk, 27"x8.5"/R14 Maxxis BigHorn Mud Terrains, In June '14 issue of Off Road Mag

AX15 Jeep Trans swap in progress....

winmutt
bitbanger

3,468
07-09-2010, 02:16 PM #5
Because my elements are all maxed out I think that I am not getting enough pressure at idle as well (lopes a bit).

http://www.harborfreight.com/fuel-inject...92699.html This should work right?

Its probably something simple, but the fact that I cant get it to happen with the car parked is worrisome.
This post was last modified: 07-09-2010, 02:22 PM by winmutt.

1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42
winmutt
07-09-2010, 02:16 PM #5

Because my elements are all maxed out I think that I am not getting enough pressure at idle as well (lopes a bit).

http://www.harborfreight.com/fuel-inject...92699.html This should work right?

Its probably something simple, but the fact that I cant get it to happen with the car parked is worrisome.


1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42

Captain America
Boostin' & Roostin'

2,221
07-09-2010, 03:47 PM #6
Gonna be difficult to monitor pressure while driving unless you have a long line connected to the gauge.

Which car is having the trouble?

Guess you've got a modified pump huh? I don't know much about the pumps yet. Sad


1982 300D Turbo ... 3,6xxlbs, No fan, No AC, Hood Stack, No ALDA, No rear bumper and stuffed front, A/W Intercooled, Injectors by Greezer and HUGE Pre-Chambers with help from OM616 & Simpler=Better, Fuel Cranked up, 60 Trim Compressor wheel, EGT, EMP, Boost 50" Rigid Radius bar on roof Aux tank for a total of 48 Gal Of Diesel! Odyssey PC-1750 Battery in trunk, 27"x8.5"/R14 Maxxis BigHorn Mud Terrains, In June '14 issue of Off Road Mag

AX15 Jeep Trans swap in progress....

Captain America
07-09-2010, 03:47 PM #6

Gonna be difficult to monitor pressure while driving unless you have a long line connected to the gauge.

Which car is having the trouble?

Guess you've got a modified pump huh? I don't know much about the pumps yet. Sad



1982 300D Turbo ... 3,6xxlbs, No fan, No AC, Hood Stack, No ALDA, No rear bumper and stuffed front, A/W Intercooled, Injectors by Greezer and HUGE Pre-Chambers with help from OM616 & Simpler=Better, Fuel Cranked up, 60 Trim Compressor wheel, EGT, EMP, Boost 50" Rigid Radius bar on roof Aux tank for a total of 48 Gal Of Diesel! Odyssey PC-1750 Battery in trunk, 27"x8.5"/R14 Maxxis BigHorn Mud Terrains, In June '14 issue of Off Road Mag

AX15 Jeep Trans swap in progress....

winmutt
bitbanger

3,468
07-10-2010, 08:09 AM #7
It happened again in the parking lot at work and not again since then.

1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42
winmutt
07-10-2010, 08:09 AM #7

It happened again in the parking lot at work and not again since then.


1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42

ForcedInduction
Banned

3,628
07-10-2010, 03:13 PM #8
Air in the lines can do that. Accumulating a bubble until its big enough to get sucked through and start over. Check your tank hose.
ForcedInduction
07-10-2010, 03:13 PM #8

Air in the lines can do that. Accumulating a bubble until its big enough to get sucked through and start over. Check your tank hose.

winmutt
bitbanger

3,468
07-14-2010, 08:08 PM #9
I did replace one of the tank hoses a few years back. If it was a gasser I would say it was skipping. Going to get a cheap fuel pressure gauge this weekend and run it into the cabin. It is VERY possible the lift pump cant keep up.

1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42
winmutt
07-14-2010, 08:08 PM #9

I did replace one of the tank hoses a few years back. If it was a gasser I would say it was skipping. Going to get a cheap fuel pressure gauge this weekend and run it into the cabin. It is VERY possible the lift pump cant keep up.


1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42

winmutt
bitbanger

3,468
07-18-2010, 04:00 PM #10
I tightened the tank hose and it seems a little better but it still is acting like it is missing. I am going to try replacing the tank screen.

1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42
winmutt
07-18-2010, 04:00 PM #10

I tightened the tank hose and it seems a little better but it still is acting like it is missing. I am going to try replacing the tank screen.


1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42

winmutt
bitbanger

3,468
07-19-2010, 10:53 AM #11
Gonna swap to and fro lines first and see how that goes.

1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42
winmutt
07-19-2010, 10:53 AM #11

Gonna swap to and fro lines first and see how that goes.


1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42

JB3
Superturbo

1,795
07-19-2010, 01:09 PM #12
(07-09-2010, 01:48 PM)Captain America I want to put a fuel pressure gauge inline after the lift pump to verify

A vacuum gauge before the lift pump would probably tell you more about the restriction vs the lift pump output.

I had both on my earlier car, and the restriction would creep pretty high before any loss of pressure showed on the lift pump output. And if you sucked air, the lift pump would jump around in pressure, instead of any consistent reading. Reading a vaccum gauge with a clean fuel line and in tank filter, its around 5 inches of mercury.

I started to notice a power loss above 10-15 inches of mercury, and the lift pump would drop down to 10-15 psi. This was on a high mileage fairly tired motor though.

1974 240D 617 turbo swap, W201 5-speed, in the works project
1983 240D 616 stock, DD
1989 Chevy Astro, 617 turbo swap, T5 5-speed, 4.56 diff, work van

JB3
07-19-2010, 01:09 PM #12

(07-09-2010, 01:48 PM)Captain America I want to put a fuel pressure gauge inline after the lift pump to verify

A vacuum gauge before the lift pump would probably tell you more about the restriction vs the lift pump output.

I had both on my earlier car, and the restriction would creep pretty high before any loss of pressure showed on the lift pump output. And if you sucked air, the lift pump would jump around in pressure, instead of any consistent reading. Reading a vaccum gauge with a clean fuel line and in tank filter, its around 5 inches of mercury.

I started to notice a power loss above 10-15 inches of mercury, and the lift pump would drop down to 10-15 psi. This was on a high mileage fairly tired motor though.


1974 240D 617 turbo swap, W201 5-speed, in the works project
1983 240D 616 stock, DD
1989 Chevy Astro, 617 turbo swap, T5 5-speed, 4.56 diff, work van

ForcedInduction
Banned

3,628
07-19-2010, 02:19 PM #13
My fuel tank produces a pretty good vacuum as its drawn down, but the engine doesn't see any power loss from it. Its been one of those "I'll get to it" things because it hasn't caused any trouble.
ForcedInduction
07-19-2010, 02:19 PM #13

My fuel tank produces a pretty good vacuum as its drawn down, but the engine doesn't see any power loss from it. Its been one of those "I'll get to it" things because it hasn't caused any trouble.

Captain America
Boostin' & Roostin'

2,221
07-19-2010, 02:24 PM #14
Ok well wouldn't the goal be no vacuum in the tank? If there was a vacuum I would say that's a problem....


1982 300D Turbo ... 3,6xxlbs, No fan, No AC, Hood Stack, No ALDA, No rear bumper and stuffed front, A/W Intercooled, Injectors by Greezer and HUGE Pre-Chambers with help from OM616 & Simpler=Better, Fuel Cranked up, 60 Trim Compressor wheel, EGT, EMP, Boost 50" Rigid Radius bar on roof Aux tank for a total of 48 Gal Of Diesel! Odyssey PC-1750 Battery in trunk, 27"x8.5"/R14 Maxxis BigHorn Mud Terrains, In June '14 issue of Off Road Mag

AX15 Jeep Trans swap in progress....

Captain America
07-19-2010, 02:24 PM #14

Ok well wouldn't the goal be no vacuum in the tank? If there was a vacuum I would say that's a problem....



1982 300D Turbo ... 3,6xxlbs, No fan, No AC, Hood Stack, No ALDA, No rear bumper and stuffed front, A/W Intercooled, Injectors by Greezer and HUGE Pre-Chambers with help from OM616 & Simpler=Better, Fuel Cranked up, 60 Trim Compressor wheel, EGT, EMP, Boost 50" Rigid Radius bar on roof Aux tank for a total of 48 Gal Of Diesel! Odyssey PC-1750 Battery in trunk, 27"x8.5"/R14 Maxxis BigHorn Mud Terrains, In June '14 issue of Off Road Mag

AX15 Jeep Trans swap in progress....

Fernando BR
617.931

6
07-19-2010, 05:18 PM #15
My 617.931 ( 300GD)/ M - IP is doing this kind of pulse when in 3rd at 2500 rpm I stop acceleration for a while and after that press accelator . Its strong if I press it deep. After two "balances" it goes like a slow rocket. Iddle is ok at 650 rpm , full load ok , top speed ok.....
May be only a time lag between injection and cilynders possition?????
This post was last modified: 07-19-2010, 05:20 PM by Fernando BR.
Fernando BR
07-19-2010, 05:18 PM #15

My 617.931 ( 300GD)/ M - IP is doing this kind of pulse when in 3rd at 2500 rpm I stop acceleration for a while and after that press accelator . Its strong if I press it deep. After two "balances" it goes like a slow rocket. Iddle is ok at 650 rpm , full load ok , top speed ok.....
May be only a time lag between injection and cilynders possition?????

winmutt
bitbanger

3,468
07-28-2010, 11:14 AM #16
I believe now it is a sticking valve causing compression loss. When I replaced my valve stem seals I noticed that one of the valves was sticking. Last night I heard what sounds like valve hitting a piston. Time to look for a new head.

1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42
winmutt
07-28-2010, 11:14 AM #16

I believe now it is a sticking valve causing compression loss. When I replaced my valve stem seals I noticed that one of the valves was sticking. Last night I heard what sounds like valve hitting a piston. Time to look for a new head.


1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42

 
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