il make it short and simple. car barley runs.. u can start it and get it to idle but once any throttle is introduced it boggs and will die. so far replaced igniter, coil, cap, rotor.. still the same result.. i ordered a new dizzy but before i install is there anythign else i should check, it has the sytoms of a bad igniter but i replaced it.. stumped checked my demon (i have neptune) nothing is loose in ecu.. i have NO CELs compression is 240+ across board... Ive went through my whole engine harness all wires seem fine.. Something that is weird is that when start or trying to start car the tach jumps all over the place. ansd when motor dies sometimes tach just sits at 1k rpms and you have to turn igniton off and on a bunch for it to go down to 0... Nothing changed with new dizzy install.

update:

timing is dead on.. Tried 3 ECU's 2 dizzys, 2 main relays.



since ive installed new dizzy symtoms where the same untill after i tried to start it the 4th time and it wont even run anymore. pulled plugs there wet with fuel... however could fuel presure still be an issue?

things i havent checked:
Fuel presure
Ignition fuse


i checked, rechecked, tripple checked all wiring everything is where its spose to be.

 

What maps are you running and/or has this thing been properly tuned before?

Have you checked to see if you are getting any spark at the plugs? You should really be testing these components rather than aimlessly throwing parts at the issue. Sounds like you may have some messed up ignition wiring.

 

This sounds typical of what happens when/if you get the TPS and MAP sensors plugged in backwards. They are both right next to each other, use practically identical plugs and can be easily switched on a factory harness in which they are not marked. Car will idle ok, but bog out as soon as you hit throttle.

 

i was going to say the same thing. You wont get a check engine light either as they are both 5v references and the computer isnt "that" smart.

 

the car is tuned on Neptune RTP for sometime now maybe 6 months. i make adjustments accordingly a couple times a month when i do data logging.

currently i havent checked to see if there is spark since the motor stop running completly.. i will do tonight..

however when the car was running it had spark on all cylinders just no power what so ever. if you get on the throttle it would sound like it was chocking for air or fuel and as soon as you let off the rpm comes up for a quick sec then goes back to a crappy idle or it dies.

Messed up ignition wiring: explain what exackly you mean?... like the dizzy wiring or the car wiring, or the engine harness or everything?

 

i checked those the car was running fine before it started acting up..

 

Check ect temperature. Or bad sensor

Also, check the resistance on the plug wires.

Air fuel ratios look normal when it runs like this?
If it does. Id assume to check timing. Something stuck in the intake as far as a bag or something. You never know. But goodluck. If i have any ideas ill post em back. Let us know if you figure it out

 

You should be able to hear the pump prime. I simple fuel pressure gauge will answer that for you. It doesn't take much fuel for an engine to idle. A bit different when you put a load on it.

 

a/f is jumpy all over the place. my manifold presure is way higher than it should be.

just curious what the ect would have to do with anything... i cant keep the car running long enough to get the temp to operating temp but when the car broke it was at operating temp...

no bags in intake lol checked all that.

 

oh yea i have a 255 (not that its huge or anything) i can defintely hear it prime...