Apex idle problem??? looking for input

[hot rod rooster]

hey guys i have a customers sled here with a bit of a problem. the sled has a mcxpress rear mount turbo with the 310 mapping on it. the sled runs fine but is very erratic when it comes to idleing. i can't seem to get it to idle very well and it takes a bit of burping the get it to rev up on the pipe. once you get it reved up it runs fine but it has trouble down low and coming off idle.

I have checked and replaced the TPS and it reads 15-95.

The one thing that really stumps me is that i can't seem to idle the damn thing up using the big black plastic idle screw on the top of the throttle bodies on the carb side. no matter what i do it doesn't make any differance to the idle........ what is up with that?

Any and all help is greatly appreciated.!!!


Thanks
Dallas

 

[WesG]

Idle balance

I have found with my apex that there is a very fine balance between the black adjustment knob, the throttle stop screw and the tps. If you move the throttle stop (inbetween the throttle bodies), you have to adjust your tps. I found I had to adjust the black knob at the very end and only for small changes in the idle.

Wes

 

[hot rod rooster]

no matter how much i move the black plastic knob it does nothing to help or hurt the idle speed?? that i think is where i am the most stumped. what exactly does that knob do in side the assembly it is attached to?

as of now i am resorting to going right back to the drawing board and checking the valve timing and go outwards from there. i have the TPS reading correctly now but will check valve timing and then concentrate on the carberation.


If someone could tell me exactly why i wouldn't be able to adjust the idle with the black knob then i would be happy!!!LOL

later
Dallas

 

[mulot30th]

Sounds like the problem I had with my apex last year.....

Hope for you it s not same thing.......


I had 8 burnt valves, all 4 bores were out of round, head was warped...


Mine had all kind of problems keep a good idle, low vacuum, and midrange throttle was so-so at best... but at full throttle, she still hauled....

 

[hot rod rooster]

well I went back and checked the valve timing, adjusted it a we bit and installed the new TPS and double checked all the vacume and wiring AND voila! if fricken idles now....... not sure what the problem was but I think I might be the TPS was bad and not really showing it in the numbers. anyways it seems to work quite well now. idles about 2000 and comes off idle good and runs strong....


a real head scratcher.