[driftingvic]

i have a 89 crown vic with a 310ho Speed Density motor in it.

Ok i built this motor a couple months ago one week later the tranny fried so i just now got everything back together. Since i built the motor it wont rev past 4100-4500. It lags off the line due to the cam then comes on amazingly strong then once i hit some where in that range4100-4500, lately its the 4500 mark, at wot the car falls flat on its face. Its as if fuel or spark where cut,then i have to lift the throttle and it comes back like nothing happened in seconds. If i let it sit in nuetral and floor it it will run off the rev limiter, if i am at partial throttle and hold a gear it will rev up past the 4500 mark. I got it up to about 5000 before i floored it and instantly killed it. i had two codes egr that i had isolated, i fixed, and that went away and bad tps which i replaced and now am code free.

here are my engine and trans specs.

Engine specs:
-stock block rods and crank bored.060" over and 0 deck
-speed pro flat top valve relief pistons about 10.1:1 compression
-Ported milled and 3 angle cut E7 heads with comp beehive valve springs and 1.72 roller rockers
-Ford racing e303 cam
-Walbro 255lph pump with 24lb injectors and adust. FPR
- stock intake and headers
-2.5" exaust header back with h-pipe and two summit racing "race" mufflers dump before rear end
Trans:
-HO AOD
-crappy ebay stall convertor
-Bauman shift kit
-Bauman valve body

im using the ecm from a 91 lincoln mark 7 and also a 90 cougar both have the same results. distributor and coil are stock from vic so is map sensor.

i first suspeceted it was fuel so i go the 24lb injectors and the fuel pump now i know i should be able to flow way more fuel than the power im making. i think its either spark or the ecm is pulling one of the two.

anyways its really frustrating seeing as how i have my wot shift point set at ~5800 and i cant even get close to it. some people have suggested plug wires or coil but i dont have the money to grab those yet so here i sit asking questions online:-P

[Blade10]

My guess is the TPS sensor. Measure the voltage on the center wire wire the key is on (engine off) and have someone *slowly* press the pedal down. You should see the voltage increase *smoothly*. If there are any sudden jumps or if it goes down instead of up (particularly where the throttle is when you have the problem) then the TPS is defective.

Blade

[driftingvic]

ok i will do that sweep check.


just to recap though it only happens AT wot AT 4500

600-4500 at wot is fine and
4500 on at partial throttle seems to be fine too.

[mustang5l21]

my mustang did that not to long ago it turned out being the fuel pump screen in the tank was clogged, so maybe check the fuel pressure mine was at 30psi when it was clogged.

[driftingvic]

well the fuel pump and pick up are only two days old so i dont really think that is it...i thought it was at first that is why i changed the pump that and a CV pump is only 70lph

[MadMatt]

What do you have you fuel pressure set at? If the motor is running rich because of too much fuel it will usually fall on it's face around 4200-4800 rpm so that is one thing I would look into.

[racecar18]

my buddies car has had that problem. his problem was the trottle timing was too high.

[driftingvic]

Originally Posted by racecar18

my buddies car has had that problem. his problem was the trottle timing was too high.

you mean his tps was out of the proper range?

ill check my pressure to see what it is basically ive just been trying to read the plugs to set my pressure.

[driftingvic]

i adjusted my fuel pressure down to where the car wouldnt run and made my way up from there still nothing. also my tps is right on at .98 so i know thats not an issue.

[Blade10]

Did you do the sweep test of the TPS?

Are you able to measure the fuel pressure while driving?

Maybe the map sensor has a problem since it seems to happen under high vacuum?

Blade

[driftingvic]

yes i ran the sweep test and it was fine im not able to measure the pressure while driving though and really i dont know what its even set at right now ill have to see if i can get ahold of a guage