rebuild on 86 b2

[cammeddrz]

if you run 19lb/hr injectors in place of the stock 14lb/hr injectors without pulling fuel pressure down to compensate you will be dumping 35% more fuel at current injector pulse widths than stock.

your MSD ignition components aren't going to help you burn 35% more fuel, MSD's "Multiple Spark Discharge" helps an ignition system burn the fuel it already has more completely. by firing your spark plugs several times in rapid succession. MSD coils, are a slightly stronger coil, but by itself doesn't do much if anything, MSD caps, rotors, wires etc. are just a higher quality replacement part. They won't help you burn more fuel either.

hope this all made sense

 

[PetesPonies]

You can't just start changing injectors because another engine uses them. This is like changing your carburetor jets to a size that a race car uses because they work so well for them. Forget that thought. What I was eluding to was that the front pump is probably the faulty one. It's easiest replaced too. But before, you need to start checking these things and not just change parts or think something is wrong when you never even checked it. A pump should make a small hmm or buzz. Typicalyl when once starts to go bad, they get noisier. Check you fuel pressure the right way and then decide is you have a pump problem.

 

[cammeddrz]

they do get noisier as a rule,

when checking pressures don't just hook onto it at idle, make sure it you check it under load, as well at higher rpm

the pump can do 99psi and 40gph wide open, the 2.9 runs 35-40psi rail pressures, so a pump operating at diminished capacity could easily feed 40psi at idle.and a 144hp 2.9 only needs around 9-10 GPH but as the injector pulses get more numerous (raise in RPM), and wider (as throttle opens) the diminished capacity pump will have a harder time getting enough fuel to keep the pressures up. you could see a drop in pressure, or "hiccuping" surges in pressure

 

[PetesPonies]

All you have to do to simulate WOT is remove the vacuum hose from the regulator. That's the only thing that effects pump pressure to the injectors. No need to actually rev the engine up.

 

[cammeddrz]

i disagree, all removing the vacuum line will do is tell the FPR you are at WOT, which shuts off the return line to prevent a sudden drop in pressure.

as the batch-fired 2.9l ecm fires each batch of injectors once per revolution. totaling at idle 6 injector pulses per rev.

at 1,000rpm, that is 1000 pulses per minute discharging a volume of "X" worth of fuel. at 3,000 rpm the amount of pulses will triple to "3X", and if the throttle is opened more than at idle the pulses will commensurately widen as well.
if your pump is able to feed the Pressure needed at idle but not the GPH needed at rev you will need to rev the engine up to see this

but pete is right, most of the time fuel pump issues do manifest at idle, but not every time

 

[PetesPonies]

Sorry, you are thinking too much. The pressure is vacuum controlled at the regulator. All that happens at different RPMs is different amounts of engine vacuum. When the vacuum drops, the regulator will shift pressure up. If you remove the vacuum line you do the same thing. All we are trying to do is see if the pump can supply enough pressure at WOT. If it can do it at WOT, it can do it at lower RPMs levels. It's that simple.

 

[broncobuckinaround]

you guys are awesome. seriously i really do think so. this more info then i could ever ask for.

i see what you both are saying. i had a feeling it was from pump. i went out yesterday and hooked up the battery and turned the key the pump has a very loud noise. and fuel just barely came out. so i imagine the pump is bad.

what is a good way to get better fuel delivery. because summit sells 19lb injectors for the b2. i was just wondering about them cuz i can easily get some off a full size bronco. you know with out breaking the bank what is a good way to burn the extra fuel to create more power from it.

 

[alwaysFlOoReD]

Unless you have a fair amount of extra money you don't want to use the 19# injectors!

if you run 19lb/hr injectors in place of the stock 14lb/hr injectors without pulling fuel pressure down to compensate you will be dumping 35% more fuel at current injector pulse widths than stock.

your MSD ignition components aren't going to help you burn 35% more fuel, MSD's "Multiple Spark Discharge" helps an ignition system burn the fuel it already has more completely. by firing your spark plugs several times in rapid succession. MSD coils, are a slightly stronger coil, but by itself doesn't do much if anything, MSD caps, rotors, wires etc. are just a higher quality replacement part. They won't help you burn more fuel either.

With more fuel you need more oxygen! You can't get that with a stock motor. You will need better intake system+cam/heads+exhaust system and/or turbo or [can't think of the name right now....I hate the pain-killers I'm on!!!].
The cheapest way to HP is nitrous.

Richard

 

[broncobuckinaround]

well of course im have a full exhaust put on. headers, magnaflow cat, and 30 series flowmaster. also going to have the intake port matched and have the heads polished. with the msd coil. and next year the msd digital box. and maybe also planning on having the cold air intake. might be enough but im not sure. i havent found any after market bold on induction kits and im working on my fab skills. just waiting on my tax return. lol its 5k. not bragging or anything

 

[broncobuckinaround]

oh and ive looked for a cam. no body in the world makes even the cam core.
but youve found one that does id like there phone number to order one.

 

[broncobuckinaround]

guys i got. what about putting on one of those thunderbird m90 supercharger with running 6-8 psi. would that be enough induction to run the 19lbs injectors

 

[broncobuckinaround]

sup guys, just re-upping the post