Is it possible to configure the K-jetronic?

[francesconyc]

I recently had my mechanic replace the heat exchanger, install a new catalytic converter, and fit a sport muffler.

I’ve always had an issue with my warm-up regulator, and I know it’s connected to the Jetronics unit under the passenger seat.

I’m wondering… when I changed the muffler on my motorcycle, my mechanic told me the engine needed to be readjusted with their software. Is there a similar procedure for Jetronics?

[Otter74]

K-Jet/CIS is a mechanical injection system - the analog computer under the passenger seat is only for the oxygen sensor feedback circuit. CIS can be tuned, so to speak - that is, everything set to operate the way it is supposed to - but it’s not done with software.

[AndrewCologne]

Originally Posted by francesconyc

I’ve always had an issue with my warm-up regulator, and I know it’s connected to the Jetronics unit under the passenger seat.

The warm up regulator is not connected to the ECU under the passengers seat. Its the frequency valve which is driven by the ECU.

[francesconyc]

the reason why im asking is because after all these updagrades etc, now i have a strange sysmtpons but easy to repeat:


when the car is cold everything runs fantastic. when the car is hot, especially in traffic during rush hours. i experience a sort of drop of the idle. from 900rpm steady, is falls to 800 or maybe even less but it doesn't die... it just sounds "mumbling" then after a minute goes bat to normal.. it very a very "digital" experience almost like there was a thermostat or somthing that decide to drop the idle and then put it back... as ai said i notced this symptom after all the work so i wonder if its a matter of jetrocnic, oxugen sensor or the old CDI box... this seems to affect on ly the idle state, the normla run is simply fine

[mikedsilva]

Originally Posted by francesconyc

I’ve always had an issue with my warm-up regulator,

What is the issue that you have always had?

[francesconyc]

Originally Posted by mikedsilva

What is the issue that you have always had?

well I THNK it is due to the WUR
is a hot start problem, which mean that when the car is hot (not as much whn i drivn on highways, but actually when i get stuck in traffic for an hour at low speed), and i park the car for 1n hour and then I restart it, either has a mumbling idle for a minute, or it takes few tries to start: you can feel it is the fuel not going throu because everything else, battery, etc is in perfect order. and u can feel is mostly a digital problem aka, it's either happenign or not. like it was a computer glitch or a bug. har to explain especially becasuse i still cant repat it ans so it;s hard to record a video to capture the entnire issue.

given that at this point i changed all the "analog" components (form FA to injectors, plugs, battery etc)) in the fuel line the only remaining culprits can be the WUR or the CDI itself

so the same mumbling is also the same i mentioned in the same first post


bottom line, i can live with it since it never impeded me to use my car regularly, but it is more of a final checklist i want to finish

i have a MSD box to replace the Cdi, and at this point im thinking to buy a new WUR, and get my mechanic to sinatll and call it a day and close my checklist...and wiht that i can also ask them to do a final pressure test to exclude any leaks, but im having hard time ot think is aleak becase it deos literally only happen in hot condition otherewise the car drives perfectly

[boyt911sc]

Originally Posted by francesconyc

well I THNK it is due to the WUR
is a hot start problem, which mean that when the car is hot (not as much whn i drivn on highways, but actually when i get stuck in traffic for an hour at low speed), and i park the car for 1n hour and then I restart it, either has a mumbling idle for a minute, or it takes few tries to start: you can feel it is the fuel not going throu because everything else, battery, etc is in perfect order. and u can feel is mostly a digital problem aka, it's either happenign or not. like it was a computer glitch or a bug. har to explain especially becasuse i still cant repat it ans so it;s hard to record a video to capture the entnire issue.

given that at this point i changed all the "analog" components (form FA to injectors, plugs, battery etc)) in the fuel line the only remaining culprits can be the WUR or the CDI itself

so the same mumbling is also the same i mentioned in the same first post


bottom line, i can live with it since it never impeded me to use my car regularly, but it is more of a final checklist i want to finish

i have a MSD box to replace the Cdi, and at this point im thinking to buy a new WUR, and get my mechanic to sinatll and call it a day and close my checklist...and wiht that i can also ask them to do a final pressure test to exclude any leaks, but im having hard time ot think is aleak becase it deos literally only happen in hot condition otherewise the car drives perfectly

Francesco,

Why don’t you ask your mechanic to test and evaluate your WUR. If the WUR is out of spec, then you could blame the WUR. A CCP and WCP measurements plus SP will be helpful information.

Tony

[francesconyc]

yeah i will do it, but im trying to collect some info beforehand so they dont overcharge me unwante inspections...

[boyt911sc]

Originally Posted by francesconyc

yeah i will do it, but im trying to collect some info beforehand so they dont overcharge me unwante inspections...

If you have the interest to learn how to use a CIS pressure tester, it will save you a lot of money if you intend to keep your car for several years. Just an hour time by your mechanic is more than sufficient to buy a good S&G CIS tester. Just my 2 cents.

Tony