any info on this nightmare car

[Tsiguy91]

Ok, here are the mods, Je 9 to 1's, crower rods, built head, Pte 60-1, buschur front mount, VPC with 550 chip, 660cc denso injectors, and a cozmo fuel pump. The car ran great, but i couldn't leave it alone. So I bought cams, I got comps, a mild set and I wasn't happy. The only power increase was from 6000 to redline. So I bought a set of webcams race grinds 276/274 ( please dont comment how they suck, or hks is better, because i have a friend who has hks's these are just as good if not better ). Ok cams are in, degree is set and the car rips, very sucky at idle, I had to run an AFC and a Gcc with the Vpc to run this thing at idle. the Afc was set strictly at -50 at 1000 thats it, because I was only pulling 2 inches of vacume. That said, the car ran great but began to get phantom knock, I replaced the lifters with the new style (solved the problem). Now I need more rev limit so I bought an eprom ecu and a chip from keydiver. The chip is a stage 3, rev limit is 9000, it is set up for a vpc 550 chip and 660cc injectors, I had him exclude the clutch options because my clutch safety is undun. Ok this car is now unbelievable, the power is sick, so I get some race gas and turn the boost up from 20-30, now its insane but when I go back to regular 94 and 20 lbs all kinds of problems, started with the o2 not reading into fully rich at WOT so I replaced the sensor. That prob. solved, then the car would just die under any load, changed the pump, to a supra pump (hard wired), prob. solved. Now we're up to date and here is my problem, the car breaks up at 6300 rpm like bad ignition wires, but they're new magnecores, new plugs, new coil pack, new module, went to 780cc injectors, -6an fuel line only pump to rail, switched to a gm maft/afc (way better tuning for big cams), spoke with key diver and he said the diff. in the burn of the chip would be -17% of fuel for the vpc/660cc set up as opposed to -40% of fuel for the maft/780cc, i can comp for that on the injector settings on the maft. Oh and I changed the pressure regulator too. ANY INFO WILL BE GREATLY APPRECIATED, thanks Marty ,
I have logs too and i'll post them next.

 

[Mirage2LTurbo]

Cliffs Notes Please?

If it breaks up like ignition, it probably is ignition.

 

[Tsiguy91]

heres the logs
with the maft on 780's, 20psi, afc zeroed
rpm- 2281
injd- 7.0%
knock- 0
02- 0.29v
tima- 28

rpm-5343
injd- 59.3%
knock- 0
o2- 0.89v
tima- 20

rpm- 6343
injd- 75.7%
knock- 1
o2- 0.87v
tima- 21
then it starts to break up.

maft set on 580's afc zero
rpm-3437
injd- 12.5%
knock- 0
o2- 0.87v
tima- 31

rpm- 5125
injd- 65.6%
knock- 0
o2 - 0.95v
tima- 19

rpm-6312
injd- 98.4
knock-0
o2- 0.91v
tima- 21
I think my problem is fuel, but it maintains pressure at 60psi under 20 psi of boost , could it be injectors, do I need a bigger pump, is it the back pulse of the injectors on the small stock rail, any answers please explain why you've come to that conclusion, not just a simple " then its ignition " answer. thanks.

 

[Mirage2LTurbo]

Have you tried new plugs, different set of wires, new coil pack and igniter since the problem started occuring?

 

[Bostedquest]

Have you tried new plugs, different set of wires, new coil pack and igniter since the problem started occuring?

in the story of a first post he mentions replacing that stuff.

Have you considered it might be spark blow out? after 22 PSI even a 50K volt ignition can get dicey...

If you are constantly going over 18 PSi, I would highly suggest switching to a MSD DIS 2 unit. Along with the appropriate hardware. That would eliminate any question of ignition problems.

And if you have not already installed that set up, WHY THE HELL NOT?

 

[hostile]

Looks like you have spent enough money on your car where you can afford a wideband.

It is either running too much fuel up top, or you have too much gap on the sparkplugs.

Try leaning it out some, or put the 660's back in there. You can probably pull -10to -15% out in the area that is is acting up. Also try gapping the plugs down to .027.

Denso 660's usually go pretty far on 1g cars they are almost like 700cc injectors anyways. More than enough for the 60-1 car if your running race gas.

Check the fuel first, THEN... do the plugs. I am pretty sure it is one or the other.

 

[Coup D E'Tat]

Marty,

I'm going to have to say to go the wideband route as well. As far as the MSD suggestion, I suppose it could be a possibilty, but people have went plenty fast on the stock ignition. Same goes for the fuel rail. You may just be running too much fuel up top. I'd look into that before anything else. It just sounds like a tuning issue to me. While your at it, why don't you sell me that EPROM?


Later,

Jesse

 

[Tsiguy91]

Ok its fixed, thanks for the help guys, did the plugs and borrowed a walbro 255 high pressure from a friend, it was one of the two. YAh I have an msd, i had to take it off because the dual output box crapped out on me, so I just need a new one of those. And a wide band is next. I bought my eprom from foreign ecu they have a ton, and they'll give you a credit on a core ecu. thanks again marty