Throttle kicker

[RobertISaar]

if it actually held the throttle open, that would essentially be another IAC, just probably not stepper motor controlled.

[Nasty-Z]

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Its a dirty mess but you get the idea .

It is the stock style 1994 TBI (Has been bored and sleeved) I retained the throttle kicker as I started with BJKW which was the factory bin for the truck.

TOM

[JeepsAndGuns]

Very interesting. Thanks for the pics! What does the valve/solenoid look like that controlls it? Is it just like the egr or ccp valves/solenoids? How many wires?
0D wiring diagrams show the tcc controll on wire E10, but 0E show tcc on E11. Interesting, I wonder why there are paramaeters for it in 0D if its not even used in 0D vehicles?


Unrelated question, whats that attached to your fuel rail in the 3rd pic, a sending unit for a pressure gauge?

[EagleMark]

From what's been reported on this it seems the Throttle Kicker is the external vacuum unit shown above that came on 454/7.4L engines. Which JeepsandGuns and I used for starting point on our conversions in $0E manual bin. But never used the external Throttle Kicker. This would explain the IAC/Idle/Error codes I had issues with. In retrospect it was the wrong bin to start with.

The first link I shared above shows pictures of TBI units with a big box on the side which I always thought was the governor and now still do.

Why it's in $0E is because that was primarily for 7.4L, why it's in $0D is probably because they had planned to use it with one PCM for all. These were very confusing times trying to get everything in order for GM, technology changing and OBDII coming along.

[Nasty-Z]

Very interesting. Thanks for the pics! What does the valve/solenoid look like that controlls it? Is it just like the egr or ccp valves/solenoids? How many wires?

No problem on the pictures, the solenoid is to the left in the 3rd picture , looks just like an EGR solenoid , by energizing it vaccum pulls the "kicker" in , unloading it from the throttle lever. 2 wires go to it , one ignition + and a siginal form E10 on the PCM (7427).

0D wiring diagrams show the tcc controll on wire E10, but 0E show tcc on E11. Interesting, I wonder why there are paramaeters for it in 0D if its not even used in 0D vehicles?

I attached the only diagram I have of the "idle speed control actuator" as they call it , it is for 4.3/7.4 manual trans and shows the output on E10 , exactally where mine is , mine is a 4L80E and FWIW I have not been able to find it on any automatic wiring diagrams so I do not know what is up with that.

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Unrelated question, whats that attached to your fuel rail in the 3rd pic, a sending unit for a pressure gauge?

Yessir , sender for an Autometer Full sweep Fuel pressure gauge.

The first link I shared above shows pictures of TBI units with a big box on the side which I always thought was the governor and now still do.

Yes , it is a governor , I have a few of these TBI's (I use them for the injector pod's) and they were all from medium duty trucks (C-60/70 style) with power take off setups .

Why it's in $0E is because that was primarily for 7.4L, why it's in $0D is probably because they had planned to use it with one PCM for all. These were very confusing times trying to get everything in order for GM, technology changing and OBDII coming along.

I have only encountered it in certain 7.4 bin's in $0E , I haven't seen it used in anything else , but could and probably are wrong.

HTH

TOM

[EagleMark]

I think that narrows down the Vacuum Throttle Kicker to $0E ?

I'd bet it does more then opens throttle at idle before starting and is on while driving to prevent throttle blades from closing inbetween shifts. For pollution reasons but side effect is easier shifting.

[CamaroDude85]

The $0D BJFD 4.3 manual bin I ended up using does not have Throttle Kicker checked but it does have parameters for Throttle Follower. One thing I found out that I haven't seen anyone mention when using a 7427 for a manual trans is having Acceleration Enrichment Limit and Closed Loop idle checked made a big difference. When I was trying to use the BHMC 305 auto bin I had problems with it going lean when pulling out and surging/bucking. I enabled both of those and it when't away completely when easing out on the clutch but would still do it pretty much as soon as the clutch was fully released unless you were above about 2300rpm. That's when I switched to BJFD and it all when't away and ran perfect.

[JeepsAndGuns]

Would be very interesting if there was a bit in the datastream showing when its turning it on and off. I'm curious to know when exactly it kicks it on and off, and by how much it opens the throttle.
So when you fire up your engine, I'm guessing it has a good flair up? My thoughts would be with engine off, no vac, TK opening the throttle a bit till engine fires and vac is produced and can pull it back?
I thought I remembered someone on here saying these pcm's take what the tps voltage is at key on and sets that as 0%? So if the TK is holding the throttle open a tad, then key is turned on, it sets that as 0%, then once it pulls back the tk, then wouldnt it be showing negative tps % numbers?

Mark, what idle and iac issues did you have? I remember on mine when I first started tuning the 7427, I would keep getting the throttle kicker failure code. I remember turning off the tk in the flags and it wouldnt pull out as good, so I turned it back on and simply turned off the error code. I would be curious to see if you did the same as I did at the start of this thread (mod a 0D 5.7 auto bin) and import the tk setting, if you would have the same results as me when you turn it on and off. Would also be curious if your idle quality and cold running performance/behavior changes for the better too.

Nasty-Z, how do you like that fuel pressure guage? Is it accurate? would you reccomend it? I have been thinking it would be cool and handy to have a electronic fuel pressure guage, but didnt even know anyone made one.