| Go back to previous topic | | Forum name | Turbo/Nitrous Tech | | Topic subject | Still mis firing. | | Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=50594 |
50594, Still mis firing. Posted by JustOne, Jun-15-03 08:05 PM
I have had this problem for a few and still can’t get to the bottom of it.
The symptom is a miss fire or surge at 1-6psi and 1/2 throttle. At WOT and ~8-20psi the car pulls normal.
I have checked or replaced:
Plugs - replaced Wires - replaced Coil pack - replaced Crane ignition - checked TPS - replaced IAC - replaced MAP - replaced Volt clamp - replaced Waste gate actuator - checked DFI - checked in many many many ways, symptoms always stay the same Fuel filter - replaced Fuel pump - checked Stock o2's (not in use) DFI's o2 - checked Lifters/rockers - replaced Valves/springs - checked
This problem only happens in boost and at ~1-7.
So I still have to check crank sensor, cam sensor and the DFI map sensor.
Do you guys have any other suggestions for me?
TIA Brian
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50595, RE: Still mis firing. Posted by MetalJim, Jun-15-03 09:18 PM
Is it individual misfiring or is it a drawn out stall situation? If it's just an intermittant individual misfiring thing then I don't know what to think. But if it's a drawn out(1/2 second or more) stall then what I'm thinking is, the only thing thats different here is "half-throttle". The thing about that is that the stock ECU strives for conservative(stoich) fueling at half throttle. It also has a more agreesive timing curve. With a DFI fuel system, the ECU will still push the timing - but is the DFI pulling enough fuel? Maybe your flooding it? There's probably a better way of testing this, but try running it into that situation, then when goes into "stall mode" shut it down immediately and pull a plug. Is it wet? I really don't know much about the DFI, so hopefully a DFI user can help you out more. If it's a drawn out stall kind of misfiring situation - or a "surge" - then it would seem to me like the DFI needs some tweaking for part throttle(stock ECU closed loop operation). This is strictly opinion, I don't have a DFI, I don't even have a turbo - just giving my .02
 95 Eclipse RS : 5 speed 15.943 @ 86.48mph Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html
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