Looking for some instruction/guidance on the idle kicker circuit -- specifically, I am wanting to know when the idle kicker is supposed to activate (pushing the piston/rod out to increase idle speed). Is it supposed to automatically kick out right at a dead cold start? Does it take its queue from the coolant temperature sensor readings? Mine does not move at all -- cold, hot, nothing -- it just sits there. Thanks.

 

The ECU uses coolant temperature, and as I understand it, A/C and engine load (computed from TPS and MAP) to figure out how much to kick the throttle.

If it's not moving AT ALL, it's probably seized up.

There are instructions on cleaning in the FSM for my 1988; but I don't have those here.

(By asking about it, I presume a 1988-1991 Dakota with V6 or V8 power?)

RwP

 

Yes, 1988 3.9 V6.

Throttel kicker -- I cleaned it out last night and regreased it, but did not pay careful enough attention to continuity and I should have tested it. BTW, you mentioned the MAP -- where is it located on our trucks (that funky looking metal grid inside the ECU box?)?

 

The MAP sensor is that thing with the vacuum hose on the firewall right between the blower motor resistor and the coil.

I'd HIGHLY recommend you grabbing a factory service manual, off Ebay or from Bishko.

RwP

 

on the manual suggestion. Ralph -- are you aware of a method for bench-testing the throttle kicker? I have read some instances where the ECU fails to send signal to the TK (rather than the TK itself being dead). But I need to rule out both scenarios. And lastly, on your 88, would you mind checking to see if your throttle kicker engages with the key in the on-position. Thanks.

 

I was able to verify... with the key in the "on" position, I am reading 8.4 volts across the purple wire and the white wire (with red stripe). So the Throttle Kicker is getting voltage, just not activating (which means the kicker itself is kaput). Will be ordering a new one here (not going to pony up for an expensive MOPAR one as plenty have had good luck with these):

 

I would need an assistant; but since I can just turn the key and it starts within a second of cranking, I'm fairly certain it's working.

That, and I bought a new one to go on when the motor was rebuilt this past summer.

RwP

 

It would have to be working as you said to fire up that quickly and not die once started. I will take your word for it. New kicker is on order -- once installed, I will report back with the results to close this one out (undoubtedly... some other schlub(s) might find this inquiry helpful).

 

... To close this one out... new kicker installed... problem fixed.