The distrubitor does not control the fuel pump? The fuel pump is controlled via an Ignition ON condition, and a signal from the air box which grounds the OCR, which completes the voltage to the Fuel Pump. It can also be controlled from the Diag. box, if this system is 1987 or later.
I have to agree with BLF. I would look into the fuel pump for sure. After we finished Marlin's 3RZ conversion, we were using an EFI fuel tank that we had out back. We just figured that the pump was good. But his truck would run great sometimes, and then poor other times. Come to find out, the fuel pump was wasted, and was not reliable at keeping a constant pressure all the time...
However, you are only getting this problem during a certain RPM range, and that would lead me to think it is not a fuel deliverly problem, or at least not a lack of fuel pressure, I should say.
How about your Ignitor? Does it have a good ground? Has it ever gotten wet?
Also, how are your Engine and Chassis grounds?
During the 2900-3000 rpm bogging, is it related to throttle position as well as RPM, or only RPM? What if you were in 5th gear at 2900 rpm, like at 40 mph, and you show plenty of throttle. How does that compare to say 2nd gear at like 10 mph at 2900 rpm with partial throttle?
It seems as though its a throtle position related problem also, it does it in all gears at that rpm range- but the tps was replaced with a new-not new used- one less than 500 miles ago.ill check out the grounds-as i have moved the ignitor and coil to make room for shock hoops, any other ideas would be apreciated-thanks mike
