Poor driveability

[portlandareae28]

SO I have a new to me 1997 F350 5spd, it has a downpipe and IC (on the truck when I got it) appears to be stock exhaust and I am not sure of anyother mods. Here is what it does.. It runs great from about 1800-2100 turbo spooling and smooth, prior to those RPM's it stumbles on itself and than about 1800 she comes to life, from 2100 on up she seems to stutter and grumble. This is my first powerstroke (I have had Cummins trucks in the past) But they (early 12 valves) pulled way harder from the bottom end than this truck does. I think something isn't right. I ordered a 6637 intake kit, and will try and get the cat tested tomorrow to make sure I don't have any blockage in the exhaust, anyother ideas anyone has??? I haven't had the airfilter out yet, will pull it first thing in the morning and run it around the block. Any and all help is greatly appreciated.

Brian

[portlandareae28]

**update** I did (4-5 days ago) change the fuel filter and throw a bottle of seafom in it with the new filter, BUT BUT BUT... when I opened the valve to drain the fuel bowl, NOTHING happened... A SILVERBACK gorilla put the last one on, so after alot of hammer time, it finally broke loose and DUMPED all over my garage floor, not sure if there is anything relating to driveability, but I think that bowl should drain with the fuel filter tightened down.. Didn't get any pressure at the fuel fill caps, but haven't tried it immediately upon shotdown

[portlandareae28]

****UPDATE***** pulled the airfilter this morning, and oh my what a mess, it is running ALOT better, does great until I really stand on it than still stumbles and grumbles a little, but definitely a huge improvement.. If I ease into it the power seems to all be there... I am thinking this truck didn't get driven a ton over the last year or two..

[Desert Rancher]

Originally Posted by portlandareae28

I think that bowl should drain with the fuel filter tightened down..

Nope, You have to loosen the cap to get the bowl to drain.

[portlandareae28]

so the truck is definitely running better, but it still stutters and stumbles from 1400-1900RPM, EXCEPT tonight when I started it up COLD (40 deg outside) to drive it home from work it runs INCREDIBLE when it is COLD, and starts to deteriorate as it warms up.... Anyideas???

[Power Hungry]

First suspect would be injector o-rings. Had a similar issue where the truck ran pretty decent when cold but as the engine warmed up it ran like a turd. Had actually suspected the injectors themselves, but after pulling them out we discovered the 3 injectors had split o-rings. A quick replacement and the truck was good to go.

If you can, check the ICP under load and if it falls off pretty sharply then it's a pretty sure bet that your problem is either HPOP or injector related. If not, you can at least eliminate that.

Good luck!

[portlandareae28]

please forgive my (bmw driving gas engine) ignorance, how do I check the ICP under load?

[Power Hungry]

Originally Posted by portlandareae28

please forgive my (bmw driving gas engine) ignorance, how do I check the ICP under load?

If you have access to a scan tool, it will be one of the PIDs. If not, then a 4000 PSI mechanical gauge is in order. Certainly, the scan tool will offer more flexibility since it can provide a host of information, but it's not without cost. Any good diagnostic shops in your area?

[portlandareae28]

What Scantool would I need????

"The Powershop" in Enumclaw Wa. is 10 minutes away, they are supposed to be good!!

[Power Hungry]

Snap-On, Mac, or Ford tools such as WDS, IDS or NGS. Also, other laptop based tools such as Auto Enginuity would work.