96 F350 PCM logic question

[ebbsrig]

I have a 96 OBS F350 7.3, 5 speed manual, EBPV butterfly removed Pedestal gutted, no cat, no chip. I had lost about all my boost due to mangled fuel pressure regulator and stuck EBPV. I couldn't see giving ford $1200 in parts to fix those issues so took care of them myself. Fuel pressure at schrader valve is right at 50 psi boost is back up to about 18-20 on a hard pull 2800-3000 RPM. I have power pretty much but am still a bit short I think. My temp rarely pulls into the normal operating range but Infrared scanner indicates the engine is warming to 180-190 *F regaurdless if I town drive it or give her a hard run to heat her up. I figure the sending unit or gauge is not quite right. My question is: Does the PCM logic read engine temp and defuel accordingly? I ask this because as I understand it stock boost should be upwards of 24 psi. I get no black smoke at all which to me indicates the boost is burning up all the fuel. That said, my power loss (real or perceived) must be due to a lack of fuel.

Thanks for inputs or advice

ebbs

[dhanna6powerstroke]

Originally Posted by ebbsrig

I have a 96 OBS F350 7.3, 5 speed manual, EBPV butterfly removed Pedestal gutted, no cat, no chip. I had lost about all my boost due to mangled fuel pressure regulator and stuck EBPV. I couldn't see giving ford $1200 in parts to fix those issues so took care of them myself. Fuel pressure at schrader valve is right at 50 psi boost is back up to about 18-20 on a hard pull 2800-3000 RPM. I have power pretty much but am still a bit short I think. My temp rarely pulls into the normal operating range but Infrared scanner indicates the engine is warming to 180-190 *F regaurdless if I town drive it or give her a hard run to heat her up. I figure the sending unit or gauge is not quite right. My question is: Does the PCM logic read engine temp and defuel accordingly? I ask this because as I understand it stock boost should be upwards of 24 psi. I get no black smoke at all which to me indicates the boost is burning up all the fuel. That said, my power loss (real or perceived) must be due to a lack of fuel.

Thanks for inputs or advice

ebbs

Not sure about the PCM reading the temp. but 16-20 psi of boost is normal on stock tuning. Hopefully someone will chime in to help you out.

[superduty4x4]

I'd say all ops normal for a stock injectored truck honestly.

[Patrick Feeley]

All seems normal to me too. 18 psi is about the maximum I saw on my 94 with open element intake, gutted EBPV, and modded pedestal (no chip). The PCM will read Engine Oil Temperature (EOT) vice coolant temperature. Do you still have the EBP sensor hooked up (electrically and mechanically)? Cheers!

[ebbsrig]

Still have EBPV hooked up electronically. I did clean the EBPS tube but discovered that when I left the EBPV actuator solinoid disconnected it threw a soft code for EBPV performance. Upon further review the 24 psi boost I expected is apparently the PCM defuel point so as I am making better that 18 I should be happy. She definatly pulls better now. I may look into an open element air filter. The CAT is already gone so I might as well open the intake airflow. When I had the turbo off I noticed some wear on the leading edges of the compressor impeller and suspected that could account for the loss of boost. I may still drop a pyro in it and go to a 1.0 compressor drive housing, perhaps pick up a more aggresive compressor wheel while I'm at it. Faster spool up and a touch more boost never hurt anyone. Will grab compression tester from the shop to make sure the compressor impeller wear doesn't translate to dusted engine. 167000 miles on the engine so as long as the cylinders are in good shape I'll be golden. I actually diesel mechanic for a living, but I work mostly with stationary power generator so I can talk Allis Chalmers, CAT, Detroit, Perkins, and Cummins all day long. The control systems on the Ford are a bit new to me and I didn't have the spec data for the engine and controls.

Thank you folks for taking to time to share your wisdom.

Ebbs

[Patrick Feeley]

Haven't seen any "more agressive" compressor wheels for our trucks. If you are thinking of the "Wicked Wheel", that is for the 99+ SuperDuty turbos (our wheel is basically the Wicked Wheel already. Cheers!

[ebbsrig]

Again, thanks for the update on turbine wheels. I'm not looking for insane power and torque. All I need is a touch more oomph when towing Horses/Mules around. What I've done so far has made a difference in normal driving. I haven't had the need for hauling yet, but I may be satisfied with what I got. If not, I will be picking this forum's collective brain. There's a ton of good info on this site....Glad I found it.

Ebbs

[superduty4x4]

Originally Posted by Patrick Feeley

Haven't seen any "more agressive" compressor wheels for our trucks. If you are thinking of the "Wicked Wheel", that is for the 99+ SuperDuty turbos (our wheel is basically the Wicked Wheel already. Cheers!

A stock SD wheel is more aggressive, but not many people put them in the OBS turbo. As you stated, its always the other way around.