N/A 7.3 Lack of Power? Bad Timing, Worn IP?

[7thDimension]

Hello all, I have a '92 F250HD ECLB, 7.3 N/A, auto, 4x4 that I recently acquired. It has 390k miles. The truck had been sitting for a few years at a friends property before I got it running.

The truck seems to start quickly hot or cold, and idles well. Throttle response is good and it doesn't smoke or rattle when it's cold. I'm not sure how old the IP is though...

The problem is that it is really, really slow, I know that it's an N/A motor, but it seems like it should be better. It has a hard time maintaining 70mph uphill empty.

The strange part is the truck doesn't smoke at all really, even when it's floored up a grade, there's no smoke. I thought if I was lugging it, it would smoke some.

When I punch it off the line, or do a brakestand, it doesn't smoke either. Does that mean it's not getting enough fuel? Or is that normal for a stock truck?

I haven't changed the fuel filter yet, but that wouldn't cause much of a restriction, would it?

 

[icanfixall]

Welcome to the forum. A restricted fuel filter sure will cause lack of performance. Can you tell us if the injectors and the return lines are painted grey? If they are grey then they are probably original and long past replacing. A set of injectors usually lasts 125,000 to 150,000 miles. Injection pumps about the same. An na engine is still able to get out of its own way. I suggest changing the fuel filter and do not buy a Fram fuel or oil filter. they are not very quality filters and lots has been posted on them. Also DO NOT buy from the cheapest ebay seller for injectors or injection pumps. Read the Hall of Shame forum for who has been found to provide poor customer service and parts. If you decide to replace the pump or injectors please ask who to buy from. This forum has tested many and found the best bang for th buck on parts. Its free for the asking but buying from el cheapo ends up costing you twice as much.

 

[7thDimension]

Thanks for the welcome and quick reply! I just changed the fuel filter (WIX brand), and it seems to start and idle smoother, but drives about the same. It'll spin the tires off the line, but as soon as it shifts to second (around 3200 rpm), the power seems to drop off sharply until the rpms get up again, it's like it has a dead spot in the powerband. And shouldn't it smoke a little on hard acceleration or uphill? It just seems like it isn't getting enough fuel, but runs great and smooth through the rpms otherwise.

I believe the injectors and their feed lines are grey, but the return lines are black rubber. The IP is silver... The IP does have an intermittent heat soak problem as well. I already replaced the lift pump. Nothing is leaking...

The PO owned the truck for a long time and it seems like he only fixed things when they broke, so the IP and injectors could very well be original.

Could a bad IP or injectors really cause a lack of power but no other drive-ability problems?

Should I turn up the fuel screw a little?

 

[79jasper]

Yes to the ip and injectors. Could be the timing also.
I had basically the same truck but 88 and zf5 with 3.55 gears. Wasn't laggy at all.

A shift kit would probably help also.

Sent from my SAMSUNG-SM-G890A using Tapatalk

 

[7thDimension]

So, the axle code on the door jamb is C9, so limited slip 3.55 gears? Isn't the E4OD electronically controlled? If so, how would a shift kit work on it? Doesn't the tcm control the line pressure and stuff?

I guess I'll invest in an IP and set of injectors at some point, and all the stuff to time it. It's like I'm bleeding money ...

I really like the truck though, so I guess (or hope) it'll be worth it in the end.

I'm considering a banks sidewinder kit also, does that make a big enough difference to be worth it? I'm planning on using the truck to tow, probably uphill a bit...

 

[79jasper]

For a diesel, a turbo is the absolute best thing you can do for it.
Shift kit will still help. Transgo tugger (?) I think it's the common one.
Let me find a link.
Here it is. http://www.oilburners.net/forums/showthread.php?t=71643
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[riotwarrior]

Welcome

You hqve a 23 yo truck has near 400K on it...dont knownhow old u are but that type of milage will wear on a truck.

Checking timing is good idea if you plan new ip and injectors it is a must.

You say po did little or only ***** that broke...and now you are saying yer bleeding $$$ well a truck of that age and miles with poor mainanence is going to nleed you until it gets up to *****...face it its not a dime store hundyei or skoda or lada it is a north american big iron truck.

Be prepared to invest near 1k on a good IP and injectors....look in hall of shame and dont buy there.

Talk to Mel...aka Agnem here at www.conestogadiesel.com also Russ here known as typ4 and then Justin not here who has IP and injectorz and is at www.idiperformance.com

Nope these dont usually blow billowing clouds of unbur t fuel known as rolling coal and in no way do we promote doing that...its wasteful and ridiculously silly. They may have a slight puff but usually not much.

Read FAQ and all the new folks stuff check out tech articles too...search is good as well.

Have fun dont get discouraged and read...btw...I should mention read...there is tons here to read lol so you can inquire with an informed idea of whats up.

Betcha ip and injectors be like 30 more hp ...

JM2CW

Al

 

[junk]

Timing can make a big difference though. So I would make sure the pump is timed correctly first before replacing it. Also I'd run a bunch of diesel Kleen or Standadyne fuel injector cleaner through the fuel system. Not saying it will be like new, but may improve it a lot.

With unknown fuel system age and the fact the truck sat a New fuel system wouldn't be a bad idea, but if it runs good and otherwise gives no trouble I'd run it.

Now the lack of power isn't right. So I'm thinking timing or possibly turning up the fuel may be in order. But you really need a Pyrometer before turning up the fuel. My truck n/a would run 75-80 no problem.

-jeremy

 

[TahoeTom]

It could be as simple as a stretched or defective throttle cable. Have someone press the accelerator pedal all the way and check if the linkage at the IP has more movement left unused. I had an aftermarket cable that had too much space between the stop and anchor at the pedal, so did not get full throttle movement. If there is slack you could try taking it up with a split shot fishing weight at the pedal end.

 

[riotwarrior]

^^^ have this issue righg now

 

[7thDimension]

It could be as simple as a stretched or defective throttle cable. Have someone press the accelerator pedal all the way and check if the linkage at the IP has more movement left unused. I had an aftermarket cable that had too much space between the stop and anchor at the pedal, so did not get full throttle movement. If there is slack you could try taking it up with a split shot fishing weight at the pedal end.

Thanks for the suggestion, I just fixed that, which has helped a bit...


And thanks everybody for the help. I don't want to roll coal, I think that's stupid. I was trying to gauge if I was getting enough fuel.

I just can't wait to get to the point where the truck looks and runs decent, I need to replace most of the interior as well...

If I'm going to get a turbo, and would like to make decent power, should I go with a moose IP and injectors? It doesn't need to be a speed daemon, but I would like to tow uphill OK, and have the ability to pass people and do a burnout once in a while...

 

[fx4wannabe]

If you plan on a turbo then I would wait and do the IP and injectors then. The turbo will require more fuel and with the turbo you have a couple more options. I would talk to Mel or Justin about what turbo and IP to get. When you are looking at dropping $2k it pays to wait a little and do it once.