89 7.3 IDI sluggish

[Zachatola]

Im new to the group and have asked a few questions here about my 7.3 IDI ranch truck. Im fairly new to diesels and im learning more and more as i go, but im not sure the best way to diagnose the issue im having and i was hoping i could get some ideas from you guys. My 89 has dual tanks, and it appears that the FSV works properly (fuel gauge only seems to work properly on one tank - another issue i need to address) however the truck seems to have ZERO power. it will move and drive around the ranch with no issues (1st gear) it seems but i took it out on a dirt road and tried to get some speed on it and it can barely get itself going. It doesnt stall or buck or anything like that but it just seems like it has no power or ability to go. I had it on flat ground FULL throttle and in second gear i couldn't get going enough to get out of 2nd, almost felt like i needed to go back to 1st.

I dont know what to look for when it comes to why it has no power. Ive changed the fuel filter about 3 months ago and its had maybe 5 miles on the truck since then. i dont see any leaks around the injector hats or lift pump, or IP. is there another filter somewhere i havent located? My understanding is diesels need quantity of fuel to increase power so dirty filters will cause a severe loss of power. I've also read that air in the system will cause big problems too but I'm not seeing any leaks or places where air would be introduced to the system.

Again im pretty new to this truck and diesels in general so any guidance is greatly appreciated.

 

[DaveBen]

This sounds like a reduction of fuel flow. Pull off the fuel line to the tank and add a clear short hose. Now run it for a few seconds. What do you see? It could be something in the tank blocking the fuel.

 

[Zachatola]

This sounds like a reduction of fuel flow. Pull off the fuel line to the tank and add a clear short hose. Now run it for a few seconds. What do you see? It could be something in the tank blocking the fuel.

Clear line on the Return line back to the tank or the feed line to the IP?

Do these trucks have a "fuel filter sock" on the pickup like many gas rigs do? Maybe that sock could be plugged?

 

[ihc1470]

What if anything are you seeing in the exhaust? Has this truck been sitting for a long period of time?

 

[Zachatola]

What if anything are you seeing in the exhaust? Has this truck been sitting for a long period of time?

Its what we use as a feed truck so it sits during the summer months when the animals are grazing so maybe half a year sit time. With that said it also never gets out on the road and "opened up". Its an 89 and has about 89k on it so it doesnt get many miles. It sat for over a year when the grandparents couldnt get it to start and couldnt get a mechanic to come look at it. When i moved to town i found a bad starter solenoid and replaced that and got it to fire after charging the battery's.

As far as exhaust goes I don't see anything crazy coming from it. If i clutch it and rev it i can get some slight smoke (greyish color?) but its not smoking constantly or puffing out black smoke. Most of the time you can smell the exhaust like most diesels but with little to no color.

 

[tdc035426]

I had a similar issue when I first got mine, the accelerator pedal assembly had some issues and wouldn't engage the throttle fully. It would rev up in neutral but wouldn't get out of its own way on the road. Had to bend the arm on the pedal and replace the throttle cable then it would actually get out of its own way. I would try having someone watch the linkage on the injection pump while you work the pedal just to eliminate the simple stuff first.

 

[asmith]

If its been sitting that much, you could have algae in the system, clogging filters pretty much instantly.

These trucks do have what is called a shower head in the tank that is known to disintegrate over time and the pieces clog up the fuel lines. It has happened to me and I had very similar symptoms of no power.

 

[Zachatola]

If its been sitting that much, you could have algae in the system, clogging filters pretty much instantly.

These trucks do have what is called a shower head in the tank that is known to disintegrate over time and the pieces clog up the fuel lines. It has happened to me and I had very similar symptoms of no power.

What did you do to fix the shower head issue? drop the tank and clean out the tank and replaced the shower head with a new one?

 

[Clb]

Hit the stickies
Here's some search criteria
As above shower heads

Algicide' kills alge and first few filters
Timing
Old bulls fsv tech 101
Fuel delivery psi
Atf fuel filter trick


+1 on been sitting to much.
Is the throttle opening completely?
Back blow air from the filter to the tanks ( 1 Atta time at low psi) with the caps off and not full so it doesn't puke.
This might clear an obstruction.

Get the fuel delivery squared away check timming.
Once it's driveable, load in down real heavy and take it out and get it hot and sweaty for an hour straingt pulling hills.

 

[Zachatola]

Hit the stickies
Here's some search criteria
As above shower heads

Algicide' kills alge and first few filters
Timing
Old bulls fsv tech 101
Fuel delivery psi
Atf fuel filter trick


+1 on been sitting to much.
Is the throttle opening completely?
Back blow air from the filter to the tanks ( 1 Atta time at low psi) with the caps off and not full so it doesn't puke.
This might clear an obstruction.

Get the fuel delivery squared away check timming.
Once it's driveable, load in down real heavy and take it out and get it hot and sweaty for an hour straingt pulling hills.

Right on, thank you. Ill search those items and check some stickys.

Thanks guys, might need to look into another filter it sounds like. Should i expect to see the filter light come on or is that light a bit of a gimmic?

 

[Clb]

Maybe it works
Maybe it don't
Don't trust nothing but your eyes with old stuff

 

[mexicanjoe]

I've had to blow back my '89 due to obstructions. My clutch fan mostly doesn't release, either hot or cold so I have a hard time keeping heat for good ignition. Sooooooo, I block off the air to the radiator and then take LuLuBelle for a good high speed drive to the ranch 38 miles away. She gets pretty warm, but if I remove a section of the cardboard covering the radiator, she cools off pretty good. Summer time is never a issue for her, winter time is different. Also make sure you use an algicide and something like "BUTCHS" to keep the injectors clean.

 

[Clb]

Linky to secret sauce please

 

[asmith]

What did you do to fix the shower head issue? drop the tank and clean out the tank and replaced the shower head with a new one?

Yeah. You have to drop the tank and remove all the pieces. you will also have to clear the pieces that have been sucked up. Either a new pick up or blowing low pressure air back through it from the engine.

You can buy new shower heads or make your own with diesel rated fuel hose.