fuel injectior flutter on race engine
fuel injectior flutter on race engine
(OP)
We are racing a Duratec 2.3L, 4 cylinder engine and are experiencing a problem with the engine that at the 6000 to 8500 rpm range the engine will stutter and act like it is misfiring. All of the ecu traces except the injector,shown as time injector is on, and rpm are smooth and look normal. The injector and rpm trace change from a smooth line to a series of short up and down traces that look like static on a dc voltage trace, that correspond to the problem of poor running. We have tried various crank triggers, MAP sensors,lambdas,and temperature sensors. Have had different fuel maps different ecus tried, with no change.I am thinking we have a bad wiring harness or connector, but can not explain why it would only show up in the upper end rpm range.





RE: fuel injectior flutter on race engine
Just a thought. Likely not correct.
RE: fuel injectior flutter on race engine
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P.E. Metallurgy, Plymouth Tube
RE: fuel injectior flutter on race engine
"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz
RE: fuel injectior flutter on race engine
What is the source of the "rpm trace"?
Look at the scope trace on each connection to the ECU. Do any others exhibit extra pulses under the abnormal conditions?
Injector traces can be difficult to interpret due to pwm current control. The other thing to avoid is triggering the scope with the injector trace itself. (It becomes difficult to determine whether the problem is interruptions to the injection pulse or additional rogue injection pulses. Use the TDC or cam sensor for scope triggering if possible.
je suis charlie
RE: fuel injectior flutter on race engine
RE: fuel injectior flutter on race engine
RE: fuel injectior flutter on race engine
Mike Halloran
Pembroke Pines, FL, USA
RE: fuel injectior flutter on race engine
Check the wiring from your crankshaft sensors and ensure they are not running too close to high-powered output wiring such as injectors or ignition primaries.
Can you post a picture of the faulty traces?
je suis charlie
RE: fuel injectior flutter on race engine
As to why it acts up at a higher rpm? It could be vibration of the pickup or the pickup can't cleanly switch at the higher frequency or some other cause.
RE: fuel injectior flutter on race engine
Never rule out non-electrical causes - even when you think you see a faulty trace. Your symptoms suggest something like a broken (inner) valve spring.
je suis charlie
RE: fuel injectior flutter on race engine
Norm
RE: fuel injectior flutter on race engine
RE: fuel injectior flutter on race engine
Knowing the signal characteristics, you could probe right at the sensor, at the ECU, and in-between, to see if the signal is conforming with the TPS position properly or not, and if the problem is in the wiring, you could narrow down which wire and at what point in the wire the problem exists.
"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz
RE: fuel injectior flutter on race engine
RE: fuel injectior flutter on race engine
je suis charlie
RE: fuel injectior flutter on race engine
RE: fuel injectior flutter on race engine