Any Suggestions?

[MillionMileMarch]

Hey Guys - I've been searching and reading all the upgrade posts I could find this morning and it seems I have hit a wall with relatively inexpensive upgrades. I'm not in a position to start spending over a 1000 dollars at a time right now. My main question is even with the few upgrades I have my truck still seems to be sluggish at lower RPMs. I'm not getting real good power until I'm well over 2k rpms and spooling pretty heavy. This is with no load at all. It feels like my truck is just really heavy and hard to get moving. Any good suggestions of what might be happening? Thanks in advance and sorry for the long post.

[silentnine]

Is your exhaust turbo back or downpipe back? If you still have the stock downpipe I would replace that. A chip would likely be your next best move.

[MillionMileMarch]

Originally Posted by silentnine

Is your exhaust turbo back or downpipe back? If you still have the stock downpipe I would replace that. A chip would likely be your next best move.

It's turbo back with 3" downpipe. And I have the Tony Wildman programmer. I'm thinking the truck is just old and maybe tired and didn't know if there something I could clean or serviced that would wake it up. I thought I read once about a screen somewhere in the fuel bowl that you could clean out.

[cndrm]

I believe the screen you're referring to is the FPR. (fuel pressure regulator) You could clean it out. You could also do the FPR shim mod. 10K resistor mod. You could also look to upgrade to a 17* HPOP. I'm not sure if it boosts performance, but there's a line you can buy, to connect the two HP oil lines. (someone just did this, and posted that they liked it)

What kind of boost are you usually pushing? You could be losing a small amount of boost to a small leak somewhere.

Also, keep in mind these are big, heavy trucks. My truck is 9200 lbs empty. There's going to be some lag if you will.

Also, what is your rear differential gearing?

mike

[MillionMileMarch]

My average boost if I'm not into is probably around 5 psi. If I'm pushing it it will get between 10 to 20 psi depending on gear, load, grade. There's no problem when I'm into it though, just seems to take a lot throttle to get any response. I have 4:10 or 4:11 whichever it is that Ford uses I forget.

That might be all it is, I'm driving a heavy truck, I don't know, I could just be paranoid that something isn't running right. I might have a history of that...

[cndrm]

Ford uses 4:10 gears. The 4:10's will give you the quickest "off the line" response. They're also much better for getting a heavy load moving.

These trucks are big and heavy. But obviously without being "in" your truck with you, we can only speculate as to how it's running. And there's nothing wrong with being "in tune" with your truck.

So if you're just cruising around, then your boost is 5 psi. And if you jump on the skinny pedal it gets up to 20 psi. Well, judging by your numbers, I don't think you have any boost loss anywhere. (so that's good)

So, that leaves you with the mods I mentioned in my last post. Personally, "I" won't do the FPR mod. Both the FPR and 10K resistor mod are supposed to increase throttle response. If I was in your shoes, and I'm close, minus the chip and gauges, then I would upgrade to a 17* HPOP and do the 10K mod.

Just thought of this. One of the things that they changed between OBS trucks, and SD trucks, is the compressor side of the turbo. You could look into moding to a SD turbo, or get the smaller 1.0 housing for your turbo. The 1.0 turbo housing is smaller, so it spools the turbo a little quicker. Not sure what the total price would come to. Might not be too much.

Hope this helps.

mike

[MillionMileMarch]

Thanks Mike - definitely helps. Good to know it's probably not my turbo.

[cndrm]

Yeah, at the cost of turbos. But, if you were losing boost, which you're not, then it would most likely be in the boots somewhere, not the turbo.

mike

[jcart]

Check your 3rd brake and other brake light bulbs...if any out the torque converter can remain unlocked and make it feel sluggish. Cleaning out the FPR screen should help with smoother idle and may assist with a bit of excelleration. To clean drain the fuel bowl down a bit....pull out fuel filter...now with a small mirror mmm say the significant others compact mirror, a flashlight and handfull of Q-tips do this..... In the top sidewall of the fuel filter housing driver's side you will see a 1 cm hole. Angle the mirror and flashlight to view in the hole, at the back you should see a stainless steel screen. If you have never cleaned it, it will be plugged with black Keeeerap. Dip the q-tip in diesel in bowl and get it in there wipe the keerap out...this will take a number of Q-tips...Keep cleaning until they come out clean...then replace filter. BTW if the filter is black you may have leaking oil past the O-rings on your injectors and probably need a R&R on them. Also put a little daub behind yer ear...an leave a little diesel on the mirror too... she will love you more then you will ever know.....no..no...I mean the truck!!

Check your Manifold Abosolute Pressure sensor (MAP). It is on the passenger side above the heater box under the hood. There will be a hose running from the passenger intake runner upto the MAP Sensor and an wired plug running out of the sensor. Unplug the sensor wire. If trucks performance improves with MAP sensor unplugged, get a new Map sensor if you "feel" no difference probably not the sensor.

cheers...

jrc

[jcart]

Another thing to check is the fuel peddle voltage. As you may know these trucks are drive by wire and thus have a voltage reostat (think that's what it is called) on the fuel peddle if you have a voltage meter turn on the key, engine off (don't start) and check the voltage out put at WOT this can be done by putting your voltage leads in the back of the plug. voltage should not read higher than 4.5 volts max at WOT....my '96 was low so I adjusted it....do a search if need be on power peddle mod if it is out of range....gonna do this to my '97 tomorrow....

jrc