Jesse405

Good info! Thanks... I checked out Harristuning and his TS page is a wealth of good stuff.

GReat! That's what I was thinking... cut where it's more accessible... I'm going to take a look at what taps came with the kit from O'Reilly's today and maybe go into the back of the TB where the fuel supply line puts in. Otherwise will go to your method! If it comes to it, you have to remove the top of the TB to get to that regulator right? Do those diaphragm springs come in different pressure settings?

HoozierZ Thanks! I suspected as much. I was thinking I might get a more accurate reading at the line split on the RETURN line?? (as that is where the regulated pressure is? after leaving the TB?) YES! very odd 44 AND 45? New O2 sensor and double checked. I am going to run codes again today or tomorrow. I will also try to get a pressure reading right at the Line In on the Throttle Body as you suggest. (Not sure I have the right tap.)

Thanks for the response! I am testing by the filter where the line splits. Also left it open and flow was great from the return line and it tested pretty much the same. My next test was going to blow air from behind filter to tank to confirm that the section behind filter is clear. If so replace The Fuel Regulator?

This truck idles fine. ONLY when you put it under load, drive it for 1/2 mile or so, it will not rev, stutters at about 1/2 throttle. If you turn the ign off and right back on - something resets and it is fine - UNTIL you drive it again. It will sit and idle fine and rev fine - as long as you don't move the truck! We have replaced the following: Fuel Pump Fuel Filter Spark Plugs Spark Plug wires Throttle Body Fuel Injectors Grommet in Valve Cover Air Positioning Sensor / Throttle Position Sensor Idle Control Valve MAP Sensor (Codes were Cleared) (Checked for Vacuum leak) Oxygen Sensor MALF CODES: OBD1 22 44 33 45 idles beautifully... and revs to 3500rmp mightily UNTIL you move the truck a mile or even less... then 1/2 throttle flat spot... won't go more than 30mph.. then ign on/off and good again Results of fuel pressure test: 1. Opened mid-run union (near filter) and KOEO bam! 18# but bleeds off pretty swiftly to 9ish, then gradually down. (Rear section bad?) 2. Re-connect union, KOEO, similar. 3. Open mid-union again and idle - bam! 18# and good flow to bucket. 4. Re-connect union, Idle - 18# (shut off.. it bled down all the way after a minute)