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Long Start?


JCE

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Im having "long" start with my engine. its a 4.3 V6 Triggers: Crank 3 teeth/Hall, Cam 1 teeth/Hall.

I understand the engine might need to turn 2 times (depending on engine position) before it gets signal from Cam and start injecting+giving spark. But starting just seems longer than a normal car engine.

Same thing with cold and hot engine. It starts immediatelly when it starts, so its not a hard start, just long....

I tried Pre-Crank prime, no affect.

Engine starts to 1200 rpm then comes down to idle speed 600 rpm

Maybe its just because of the triggers? And its not really a problem, just a "Feature" ??? ;)

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The way to tell is to see when the ECU shows RPM. As soon as it see RPM then it should be trying to fire.

If it is taking a long time to get triggers then it will take a long time to start.

If however it sees triggers and RPM quickly and doesn't fire then we are looking for another issue.

Also if you are using a stepper motor for idle control it might be due to a key on lockout while the stepper resets.

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Im using key-off for stepper reset+ecu hold power and key-on fuel lockout is 0 sec. Just feels strange it takes so long to start, my car start alot faster....when it starts the rpm goes upto about 1200pm then comes down to idle speed 600rpm, so i assume it is getting enough air @ start.

Uploaded my map if u see anything strange in it.... 8-)

base map 7-2012.zip

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  • 2 weeks later...

Still having a long start :? Been trying out all the crank enrichments but doesnt seem to affect. I watched a video of a Mercruiser MPI starting and it start up alot quicker than my engine. Guess i need to check how fast the ecu gets the triggers and sees rpm.....Will do that tomorrow. And as before engine runs without any problems etc

The engine doesnt "FIRE UP" like most engines. Maybe it is a "hard start" after all but whats causing it is another thing...

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No, 98E5 . Always same fuel.

My cam trigger is a hall sensor and the triggerwheel is Half/Half. Should i use cam level instead of cam pulse. Could this affect the starting?

What are the benefits of a cam level type of triggering? It gives 2 position signals? Rising+Falling, instead of just 1 ? Many cars seem to use it....

And i always let the fuel pump do its prime, before cranking.

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Been testing with Cam level, no affect.

I believe now it has something to do with warm up enrichment. Engine start fast/good when @ 50-60C.

Maybe too little fuel or too much.... hmmm.

But @ idle with cold engine 10-15C AFR is around 11,5, then leans out with temp to 14 when warm 70C.

:lol::lol:

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