Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Attn: Wrenchheads, help me diagnose my truck's lack of power.
#11
OK all, thanks-

To follow up, as BGnR pointed out it is throttle body injection, so it has injectors but they inject directly into the throttle body which is nice since you can watch them inject. Not fuel injection like some of you may be thinking. I will hit the injectors with some cleaner after I change the filter.

If I floor it from a dead stop, it accelerates well up to about 15 mph then it hesitates and feels under powered but will finally get up to speed. When I don't jack rabbit, which I never do, then I can't really tell that there is a problem. So it only is noticeable when I ask it to get up and go- rare.

Compression, I had the compression checked at about 190,000 and it was at 90% of spec. I change the oil/filter regularly and I am not an aggressive driver, but with 250,000 it could be compression. I really don't want it to be compression, but I can get a crate installed for ~$1500 to $1600 around here.

Anyway, I bought a fuel filter and an air filter. I replaced the air filter and it actually felt a little better, but still not right. Fuel filter is next.

I had a feeling that there might be a second fuel filter, in the tank sounds familiar now that I hear it.

Manuals- I actually have the manufacturer's service and schematics/parts manuals. I don't know why I didn't think to look there.

Catalytic converter? Never even occurred to me. Since they stopped tailpipe testing in NC, I wonder if anyone would ever notice if I had it removed altogether. I know a guy who knows a guy.

I gapped the plugs and I used a wire not one of those round gradual wedge things. I can't believe that I need new plugs and wires already. BGnR- 6months, are you kidding? What makes you think that they are cheap anyway? I got the middle of the pack wires and platinum plugs. If the filter doesn't work, I will pull the plugs, wire brush them, and re-gap. If that helps then I will replace them.

[EDIT: I replaced the plugs and wires about a year ago. Jan 06.]

I will run a bottle of STP as well to mop up some water if there is any.

Fuel mileage is fine. It has dropped about 5% over the last 70,000 miles. I keep track of it because the gas gauge doesn't always work. This is only complicated by the fact that the speedometer/odometer doesn't always work either.

I remember that I did almost run out of fuel about 2 weeks ago. I was accelerating up a moderately steep hill trying to get up to highway speed. It stuttered so I immediately got off and went 200 ft to the gas station and refueled with premium. I definitely could have stirred up the muck now that I think of it.

Jim- blow it. Smile

I'll report back. I am going out to change the filter now.
Reply
#12
Good luck with the filter. I need to do the one in my truck, but I couldn't get the damn thing off. It is rusted into one big piece. I'm going to wait till summer and soak the crap out of it with a liquid wrench or something similar and try and get it apart without wrecking the fuel lines. Also need to drop my tank...my fuel pickup fell off the pump, so I only get about 15 gallons of gas before it can't get anymore gas.
Reply
#13
"it accelerates well up to about 15 mph then it hesitates and feels under powered but will finally get up to speed"
Have you considered a transmission problem? Most people never service the tranny. It sounds as if once you get past a shift point you're OK. Just some food for thought.
Reply
#14
"I know a guy who knows a guy."

some of the greatest words ever typed.
Is he the guy behind the guy?

Now knowing you ran low on fuel, I also think changing ALL fuel filters (see your manuals) would be a cheap, quick thing to do before going big money.

Depending on how the fuel system is set up, you may want to CAREFULLY disconnect it from the engine and let some run through into a gas can to really clean out the lines. If you've never done this, let a mechanic do it, because depending on the pump, you'd be surprised how much gas can pump on to a hot exhaust!
Reply
#15
Do Not Disconnect the Fuel Line!!!!
I am almost positive that it is under High Pressure and will shoot fuel all over the place, very dangerous!
In fact you can't even disconnect high pressure lines without a special tool.
This isn't 1953 folks!

BGnR
Reply
#16
[quote Baby Tats]OK all, thanks--Jim- blow it. Smile
Blowing!

And, you're welcome.
Reply
#17
You sucked up dirt into the sock that covers the input to the gas line in the gas tank
Reply
#18
OK, done.

The bad news is that Mrs. Tats had to stand outside in 35 degree air at 10:00 at night with a fire extinguisher and a blanket. She was good about it though. I normally don't like working on the cold ground but when the humidity is 35% I was glad to be grounded.

Better news is that I didn't catch myself on fire. I was really worried about sparking a tool or discharging some static. I attached the jumper cable to the frame and my pants and stabbed the other ends into the ground. I also pulled up a pant leg to ground my skin. It sucked, but I am safety paranoid having spent part of my career as a health and safety officer. Also, I was wearing nitrile gloves and my safety glasses. The safety glasses were a good idea since I did get a drop on one lens. I am always amazed to see people doing work without safety glasses. It would suck to be blind.

I slowly backed the fittings out and caught the drips in a coffee can. Maybe two ounces came out- mostly from the engine side. When the filter was loose, I turned it over to dump it and dark particulate matter came out. HMMMMMMMM.....

Best news is that it is fixed- works like a charm. I GOT POWER, BABY. Now it feels like 300 horses again. I am going to run a bottle of cleaner through the system (does that stuff work?) and spray the throttle body and injectors with carb cleaner for good measure.

Thanks for all the help.

PS- The transmission was replaced at about 180,000 and a transmission cooler was added. Stepfather burned out the old one towing his RV. One thing that I don't have to worry about for awhile.

PPS- I love this truck. 250,000 on the original engine. I think it was assembled in Canada out of Mexican parts. Smile I can look under the hood and identify almost everything I see. There is so much space in the engine compartment that I could sit in there when working on it. And since it is 4X4 there is plenty of clearance so that I can get under it without jacking. My only complaint is the mix of SAE and metric sizing, WTF?
Reply
#19
SAE & metric- welcome to america.

I would also have suggested the Catalytic converter, but I'm glad it wasn't that for your sake. My dad had a 1990 F-350 (7.5L V8) where the cat rusted out and got really blocked up. You could floor it and get like 10 mph at the most, your problem didn't sound quite that bad.
Reply
#20
Glad to hear you got it working. I just replaced my fuel filter. Similar issue. Big Grin

Following the instructions in the repair manual eliminated the pressure in the fuel line. Very easy and my truck is high enough that I didnt need to jack it up either.

MORE POWER! ARGH, ARGH, ARGH

Carm
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)