Losing Engine Power Periodically

[stationjj]

I have got an issue where I lose engine power periodically. It started a month ago. I have been trying to find a common thread and reproduce the problem with no luck. This isn't a chronic problem at all.

I seem to lose power when trying to accelerate a hill mostly. It doesn't happen all the time on every hill. The engine won't die or cut out, but I can tell I am losing power. It will last for maybe 30 seconds and then I am fine. Today I drove the CUCV for 60 miles. About maybe 15 miles into the trip and after a 30 minute stop I started loosing power then I recovered. Then about 1 mile from home I start loosing power again.

I looked at the TMs and did some research. The common suspect issues have been checked

• Air leakage, My hoses seem good. Most have been replaced or checked.
• clogged fuel filter, In June I switched to a screw on type filter.
• I have an electric fuel pump.
• Low on Fuel, I put 21 gallons into it recently
• The IP was rebuilt by Previous owner. Maybe 1000 miles on the rebuilt IP.

I am no mechanic, but my thoughts are that maybe injectors are dirty or trash in fuel and fuel filter isn't catching but causes issues with injectors?

Any thoughts or suggestions?

Thank You,

stationjj

 

[southdave]

fuel preasure is too low or crappy fuel.. try filter swap agian and check pump. also do you have pre filter in front of pump.. some that diesel additive might help if you have water in fuel.

 

[JGBallew]

I have got an issue where I lose engine power periodically. It started a month ago. I have been trying to find a common thread and reproduce the problem with no luck. This isn't a chronic problem at all.

I seem to lose power when trying to accelerate a hill mostly. It doesn't happen all the time on every hill. The engine won't die or cut out, but I can tell I am losing power. It will last for maybe 30 seconds and then I am fine. Today I drove the CUCV for 60 miles. About maybe 15 miles into the trip and after a 30 minute stop I started loosing power then I recovered. Then about 1 mile from home I start loosing power again.

I looked at the TMs and did some research. The common suspect issues have been checked

• Air leakage, My hoses seem good. Most have been replaced or checked.
• clogged fuel filter, In June I switched to a screw on type filter.
• I have an electric fuel pump.
• Low on Fuel, I put 21 gallons into it recently
• The IP was rebuilt by Previous owner. Maybe 1000 miles on the rebuilt IP.

I am no mechanic, but my thoughts are that maybe injectors are dirty or trash in fuel and fuel filter isn't catching but causes issues with injectors?

Any thoughts or suggestions?

Thank You,

stationjj

Do you hear the engine losing RPM? or is it a matter of "feel"?

Not saying it isin't an engine issue, but I'd also check the rest of the driveline. Trans issues can make you feel like you're losing power, and in bad cases a damaged/worn/improperly lubed diff can do it as well.

being an intermittent issue raises all kinds of probabilities.

 

[donalloy1]

Possibly getting air in system before IP? Had same problem with my O9. After replacing IP and all Fuel supply lines it stopped. May the Force be with you!

 

[stationjj]

Thanks for your input. I agree with the problem being intermittent it's hard to track down and could be numerous things.

This afternoon I took her on a drive to try and reproduce the problem. We did over 25 miles up and down winding hills. Not once did she it hesitate with power.

I am at a lose on what it may be. I don't want to start tear into things hoping I find something. If it's not broke don't fix it!

I do use a diesel conditioner from stanadyne that someone gave me.

As someone on SS told me one time. Be patient with her and the problem will present itself.

Guess all I can do is check simple things. Well I got a thanksgiving trip coming up to the Huntsville Alabama area.
I will see how she does, and report back.

stationjj

 

[cuffnstuff]

Any chance it might have fuel pump problems?

 

[southdave]

see if rears its head as you approach E on fuel gauge..

 

[stationjj]

Well, I took my thanksgiving road trip. About 100 miles.

The trip started out great rolling down the interstate with no worries. Keeping her between 65-70 mph.

I stopped about 50 miles into the trip for a bite to eat. It was at a Love's Truckstop so I figured I put a little fuel in her. I don't trust fuel gge. She held 9 gallons.

The next half of the trip was touch and go the whole way. At times I would go 60 mph and then it would steadily loose power. At times I was doing 45 MPH.

When I pulled her off the interstate and driving her through the city she was fine. I started her up this morning no worries and and drove her around the city again she was great.

I am guessing trash in fuel lines or filter? Maybe both. I am thinking I stirred up some trash?

Any thoughts or input?

Thank You,

stationjj

 

[southdave]

Thays kinda of what I thinking.. I don't know the timeline of your mods. My thought is the the electric pump is dislodging crap from the tank ect..
Did you install a small prefilter before the pump?

 

[chevyCUCV]

Do you still have the stock fuel sock in the tank?

 

[stationjj]

Update.

I got the CUCV out today she did good most of day. Even when I got the front end stuck. That's a different post.

Suddenly driving on city roads I was going around 45 MPH and I Lost power and she died on me. After about 10 minutes I got her to start again.
I drove another 10-15 miles with no issue.

I finally tracked down a fuel filter for her late this afternoon. I have fuel filter ready to go. I have not installed yet.
I do not have a pre filter on the electric fuel pump. I do suspect I have the stock fuel sock as well.

The sign seems to point to trash in fuel clogging things up.

My plans are as followed;

Replace fuel filter ( current one as maybe 800 miles)
Put in a pre-filter on electric pump.

A future project I am considering is pulling tank to be cleaned and replace fuel sock.

Not sure about how to tackle pulling fuel tank. I suspect someone on SS as done the job. I think there my be something in the TM -34?

What are your thoughts? Any suggestions?

Thanks everyone for your input.

Thanks,

stationjj

 

[chevyCUCV]

I removed the sock, and put a pre Lp filter.

Cleaning the tank is easy once it is out, dump out all fuel, add some gasoline, shake it around, drain repeat.

 

[toyrunner95]

yup i had the same problem. its your filter 99% positive.

 

[Keith_J]

Dropping the tank isn't too hard on 1008s. Absolutely dreadful on 1010s and 1031s because the hoses on top of the tank are hard to get to. I have no experience on 1009s but have dropped similar tanks on cars. The common element in all is get as much of the fuel out as possible. And install it bone dry. A spare hand or two is great to have.

The sock in the tank is the first line of defense, when you get water in the fuel, a slime develops which will block the sock if there is enough of this bacterial slime. Don't get rid of the sock, it also helps prevent unporting the intake to the pump due to sloshing when nearly empty. Replace it if broken

 

[combatmech]

Ditto, I've had the tank out of my current M1009 twice. The biggest pain is having to cut most of the carriage bolts off the bumper to remove it. Unless the tank has been off the truck "recently", a grinder may be required. LMC carries a carriage bolt kit for the rear bumper.
The TM will give you plenty of reference. My first M1009 had a similar problem...It was the sock in the tank.