...The popping is fairly constant when accelerating, 3-5 pops around 3000 rpm. Once I am cursing around 2000 rpm the pops stop, but the motor feels sluggish.
Maybe someone else knows, or we can query Garry, but do these DIS setups also have a function that retards timing a lot while the engine is cold?
We used to have that problem a lot with wiring up TFI setups because any voltage on pin-6 (or whatever it was) at the TFI would fool the computer into radically retarding the spark. Made for some very sluggish running engines above about 2500 rpm.
Though now that I think about it, I'm thinking they would not even run above 3000 or so. Maybe not the same thing then.
If this was related to the issue, it might be a coolant temp sensor, or intake air temp sensor.
My setup is basically the BC Bronco and WH accumulator setup. The fuel tank is one of Toms 23 gallon tanks. I run from the tank to a glass case filter, then the lower pressure pump, to the accumulator, to the high pressure pump, to a fuel filter, then to the engine. The accumulator, high pressure pump, and filter are basically under the drivers feet.
I was trying to figure out how this could be causing problems when I read you saying that it happened even without the accumulator and low-p pump. Well bummer!
Still sounds like a potential fuel deliver issue though.
Did you happen to leave all the filters intact when you removed the accumulator? Maybe you're just suffering from a partially clogged filter, or filters.
I did replace the original fuel rail to one with a return line. The return line goes to a T on the accumulator, the other end goes to the vent on the fuel tank.
Why two return locations? Seems like it just introduces potential issues, where a single return point would be sufficient.
I think most do the "T" to the accumulator, but allowing it to all run back to the tank would theoretically let the fuel run cooler overall.
Cool fuel aside though, running to the accumulator would theoretically keep the supply of fuel in a more ready condition.
Not sure if there's an advantage to one or the other, or if both are even an issue. Just throwing out thoughts at this point.
On the fuel tank I am using the 2 metal lines that originally ran to the charcoal canister, but one line takes the return fuel from the accumulator and the other line goes to a vent mounted on the fire wall. At one time I removed the accumulator and low pressure pump, but had the same problem.
Do you notice the problem getting better or worse when the tank is full, vs when it's almost empty? Just wondering if the return line is causing too many air bubbles next to the fuel pickup area? Not sure it's a thing, and it certainly would not be when the tank is full. So if you get the issue when the tank is full, it would seem to not be a cavitation issue.
Perhaps as an experiment crimp down the flow of the return line. Using locking pliers, or better yet those specialty pliers designed to cut off the flow of rubber fuel lines while you work on the system. Made of plastic with no sharp edges on the jaws that would cut the hose.
Try crimping it down ahead of the accumulator first, then back at the tank to see if anything changes.
Most of the time it is just popping, but sometimes when it is hot it will get where it does not run well at all. The cure I have found when this happens is to burp the fuel line going into the fuel rail, almost like there is too much pressure. When it is trying to run before burping it, the fuel pressure gauge is jumping up and down. This does not happen very often.
To my mind, a good indicator that something is indeed amiss with your fuel delivery system. It should be steady and strong. No air should be able to be introduced into the system at any point I would not think. Any air in a port fuel injection system would end up leaning out the mix, and at the very least would result in a cough now and then. Or if consistent enough, the lean popping you're experiencing.
I can get some pictures or part numbers if that helps in this mystery!
Yes please!
Paul