RPM drops when clutch is step on?

[sam]

Anybody experience this. Whenever I step on my clutch my rpm drops from 900 to 6-700. Don't no why, and I check all my vacuum and there in the right place. Oh by the way I'm using a BP engine. Appreciate the help!

[georgeb]

Might have something to do with the switch at the top of the pedal (not the one on the side).

[Movin]

An auto computer lowers the idle speed when dropped into gear.
You may have the auto computer hooked to the wrong signal on
a manual tranny. Doing a swap you may have done the equivalent
with the parts you have, check that angle.

[sam]

An auto computer lowers the idle speed when dropped into gear.
You may have the auto computer hooked to the wrong signal on
a manual tranny. Doing a swap you may have done the equivalent
with the parts you have, check that angle.

Ok thanks, ill try to replace my ecu. I did remember getting a spare ecu from the yard and might have installed the auto instead of the original manual one.

[doi_doi]

this also happen to carbureted..ive experienced it..dont know why..

[bravekozak]

Now you know why I threw out my ECU. Good old fashioned carbs don't need computers. I hate it when preprogrammed chips tell me what to do, or do wierd, uncontrollable things with rpms, idle speeds, accel, decel, etc.

[bravekozak]

I am not trying to say that the Kia ECU has a Manchurian chip inside of it, but you never can tell. I wonder if there are hardware Trojans in our electronics with wireless cryptographic ICs? We won't find out until WWIII.

[Movin]

Make sure the wiring is going to the correct switches, but if you have one to swap
in that is great!

[WmWatt]

The computer system is there to optimize fuel efficiency and reduce pollutants through more complete combustion. It compensates for individual engine differences including wear on higher milage engines. Disconnecting the computer removes that advantage.

[sam]

Make sure the wiring is going to the correct switches, but if you have one to swap
in that is great!

Wiring is correct and will put the BP manual ecu. Let's see if this will solve my problem.

[sam]

Installed a different ecu(manual) still no luck. Any more tips. I'm thinking of replacing the entire throttle body assembly, since im thinking i might have a faulty IAC.

[Movin]

Unplug your transmission and clutch switches one at a time to see if
a switch might be faulty. Test one at a time.

[eurotiva]

You can also run with the iac unplugged

[Movin]

The computer system is there to optimize fuel efficiency and reduce pollutants through more complete combustion. It compensates for individual engine differences including wear on higher milage engines. Disconnecting the computer removes that advantage.

I work on computer systems every day , If I see a stripped 4 cylinder come
in with header, weber, mechanical disty it sure makes me smile!!
The last one was a show car VW, dual dellortos, header, old tin..lopey
cam...Bad side, the car was full ( 2 seat only ) of fancy stereo stuff and
more water jet art that was chromed than I have seen anywhere else..

About computers though they will do exactly what they were programmed
to do or do nothing. This one is doing something so it either has the wrong
program or bad information going in. So many things are assumed as well,
I assume that the IAC is working correctly the rest of the time..

[bravekozak]

The use of a computers on a car engine has increased the efficiency of an internal combustion engine from 32% to 33% (until something goes wrong with the electronics).