1st problem: On the wire and fuseable link they give you to run from the alternator to the fuel pump, the fuel pump side of the fuse keeps trying to melt. I'm not sure where to even start on this one. I've never seen anything like this happen before.

2nd problem: While I'm going down the highway and get into some boost, the car won't accelerate smooth and consistently. It accelerates, but it jerks a lot. Again, I'm not sure where to even start on this one either.

Any help would be greatly appreciated.

 

The jerking is a fuel or spark problem. Did you change your ignition, coil, wires, cap, rotor, distributor, plugs. I am pretty sure you have to gap the plugs at .035" or you can blow out the spark. The other is fuel. If you didn't up grade the pump, filter, injectors you are probably going to have problems. I am not a blower guru but when any engine surges it is usualy one of these two problems. When I bought my 91Z I changed all of the above and picked up over a second just because the stuff was over ten years old.

 

<b>On the wire and fuseable link they give you to run from the alternator to the fuel pump, the fuel pump side of the fuse keeps trying to melt. I'm not sure where to even start on this one. I've never seen anything like this happen before. </b>

Im not 100% sure but let me throw some reason at you:
#1 the fuse is not big enough, regardless of what came with the kit.
#2 there is a grounding problem somwhere in the wire
#3 the fuel pump is improperly grounded *or* is getting too much / little voltage. Does your fuel pumps pressure regulator change the voltage in order to lower pressure? some do, some dont.
#4 you say "keeps trying to melt" do you mean you keep replacing it and it keeps melting or are you using the same fuse and it keeps getting close to melting? I would immidiatelly replace the fuse with a new one, doesnt have to look the same just get the same # amps. an in-line fuse from home depot would work. maybe step up the amps a little too.
#5 bad relay. Are you using a relay to run the fuel pump? If the relay goes bad, it will ground out somtimes. Rare, but happens.
#6 ?? not sure, just trying to help. Hope i didnt do more damage than help. First thing I would do is put a bigger /new fuse in and see what happens.

As for the jerking, I agree with KS... Either your detonating under boost (too hot -whats your temp at? should be under 190 technically***) or too much spark (time for better fuel / spark retard?)

**OR** considering you have a FUEL PUMP FUSE PROBLEM and your car isnt GETTING ENOUGH FUEL I would put 1 and 1 together and say "hey, maybe its the fuel pump /wiring/relay/fuse!"
just wo du suh $0.02

 

Ok, just to answer a few of the questions, ...... all the plugs, wires, cap, rotor, coil are new.

The plugs are gapped at .035.

The fuel pump is the second in-line fuel pump that ATI supplies with the kit.

I'm using 91 octane.

I don't think the fuel pumps pressure regulator changes the voltage in order to lower pressure. I think the FMU stops the return flow back to the tank, thus raising the fuel pressure.

When I said "keeps trying to melt", I meant that I'm on the second fuse right now. Neither fuse would blow. All the plastic on that side of the fuse starts melting.

The second fuel pump is on a relay.

As for the jerking, I've suspected detonation under boost for a while now. I'll have to pay closer attention to the temperature next time it does that.

I really appreciate all the ideas guys. Thanks again!
:hail:

 

Food for thought

Right before I shredded my last belt on my blower, I was experiencing some inconsistent boost and jerking at high speeds, like on a freeway.... 'twas belt slip as the culprit on my car.

Jon

 

I put a P1SC on a friends Mustang and we had similar belt troubles. This may be totally different for the F-body but maybe this'll help.

The belt ATI sent was REALLY tight. So tight that we didn't use it. We used the OEM length belt and bypassed the smog pump. It worked fine, on the initial 3am test drive. Then we got it on the dyno. The dyno guy was saying it only made 7 psi (with "14 psi pulleys"). So the next run I watched as the belt flapped up and down almost 6"! The tensioner was stretching all the way out. Even tho at rest it was in the middle of the range, as shown by the ticks Ford put on the tensioner housing. It took 4 guys to jamb the "ATI belt" on, but it went. It's really tight but no more slipping and flapping.

 

I'm leary of tightening my belt up anymore. I'm getting little to no belt dust right now, and I've heard horror stories of guys snapping the snout off their cranks from running with their belt too tight. Besides, it's generating the correct amount of boost.

 

My money's on something fuel-related

 

check this ultimate belt post

 

Yeah, I read that post about 4 or 5 months ago. I have a poly-cog belt on it right now. It seems to be working great. The problem feels more like a detonation or fuel problem to me.

 

remember forced induction creates heat. Just because your temp goes from 180 to 220 at 8 PSI of boost in under 10 seconds doesnt mean your detonating.
With 6 PSI of non-intercooled boost I would see temps rise from 170 to 220~ in about 10 seconds. My cooling system simply could not keep up with the blower however, so even when not under boost my fans were always on. But im just giving you an idea of how hot it can make things... even when your not detonating. heat can LEAD to detonation however, so if you START at 220 degrees and hit 240*~ during a run you might start detonating...
Hope you have forged pistons!

<b>As for the jerking, I've suspected detonation under boost for a while now. I'll have to pay closer attention to the temperature next time it does that. </b>

you have a TPI computer right? Dont you have a knock sensor? Or is it one of those "goes off no matter what so i disabled it" things.

 

I had a set of hooker shorties and dumps nearby that when I ran uncapped the exhaust pulses would whack the ESC (knock) sensor which would make it cut out badly, so I had to unplug it when I raced uncapped but I ran race fuel for safety because I was running Nawws too.

 

Yes, I have a TPI computer. Yes, I have a knock sensor. No, I haven't tried disabling it.

I also have forged pistons.