rev limit backfire @5k on an i motor??

[dmjensen]

i have an i motor on ms pnp ecu and ive been road tuning it but when i get to 5k
it sputters and backfires and acts like a rev limit but i checked the rev limit and its set at 6200/6500

spark plugs are gaped at .023 and it runs just fine until i get to 5k everytime. even in neutral with out a load on the motor


is it possibly a bad crankpos sensor or even its too far away?

[Jaxx_]

post up your msq

[dmjensen]

Explain to me how exactly to do that really quick, i just dove into this yesterday so i havent learned how to do everything or the terms for some things

[dmjensen]

heres a data log with a few pulls to the point where it starts to act up

jaxx i know what you mean now, i just haven't figured out how to post it for you

[dmjensen]

also my afr is the stock sensor so please ignore that haha

[LowR3V'in]

Get your .msq and datalog.
Zip them and attach to your post.

Maybe alittle info on your setup before the obvious questions like
do you have a wideband or are you really doing 50% duty cycle just on a freerev.

[dmjensen]

I have a wide band (its on a gauge and i havent quite figured out how to splice it in place of the stock o2 since its a 6wire lc-1) and ive been roadtuning it but im leaning twords it being more that sensor or possibly ive reached my fuel limit because i had my dad ride with me and listen to it and he said that the motor is cutting out similar to a revlimiter almost if the engine is spinning too fast and the sensor is just getting a weak or bad signal.
But ill get my tune up for you and possibley another data log.

[dmjensen]

this is the free rev log

[LowR3V'in]

can't see shit.

Increase resolution by pressing the up/down keys.

[dmjensen]

sorry

[LowR3V'in]

.Zip your log and msq, then attach them to your post. It could be anything.
Is throttle position really 26% or are you flooring it?

[dmjensen]

Its really 26%

[whodwho]

How did the CPS check out?

FYI the 26% throttle position is a non variable cruise signal, with a stock TPS installed it gets a fixed 0, 25, 100% signal for idle, cruise and WOT from the stock TPS switches.

[dmjensen]

I looked at it again and the book i have says it should be .0300 to .0500" and i could probally fit a bic pen in there so im going to adjust it with a feeler gauge tonight.

And when i had the miller setup it requires you to cut the WOT wire in the tps conector, should i reconnect that probally?

[whodwho]

The idle signal is probably good enough for most of the features that you would need a TPS signal for but it wouldn't hurt if you were needing something else to do :)