Tampa 928s

88 S-4

I have installed two of theses one on an 85-Euro and 86.5 with great results, holds Rpm to red-line on all gears.
I just added one to an 88 S-4 and notice I do not get top full rpm there is a difference but not as dramatic as the other two. I can hear the tranny solenoid kicking in so I know that's working. Is there a possible issue going on with the tranny?

soupcan

Try adjusting the bowden cable.

Tampa 928s

It has been adjusted no slack but not tight, shifting good otherwise!

Tampa 928s

Loosened bowden two turns and a minor change seems to max out at 5.3K if I let off the pedal it wants to shift to second before maxing out in first.
What is the results of anyone else doing this, are there differences from 85 to 88?

IcemanG17

88S4 running properly SHOULD shift at 6000 to 6200rpm....mine did that and it ran well....

If you are shifting that early (5300) I'd say the cable is too slack....however tightening it up comes at a RISK..... #1 you could pull the TPS (throttle position sensor) off the idle contact....but thats easy to check since it "clicks" when its working (check with engine off of course)...

The TPS only has 3 positions..... IDLE-CRUISE-WIDE OPEN.....

Tampa 928s

I had it tight no side deflection, I will try going a little tighter tomorrow. I have the accelerator adj good for idle and wot so if this does not cure it I am wondering about a sticky power valve.

Tampa 928s

I have tried everything to get it to shift near 6K it's around 5400. I placed a meter on Wot 3/5 pins verified; closure idle switch is just off throttle but if I adjust tranny cable it maxes out pulling on Throttle linkage causing the Wot to not operate. I have tried every conceivable adjustment, do I have an issue with the control pressure?

SeanR

Tampa, I've not found the cause of this as my '88 does the same thing....sometimes. It's almost a 50/50 thing, sometimes it will go to redline, sometimes it goes to 5500. I can also tell that the car feels much faster on those times it goes to redline. Not talking feels better because it's up in those RPM's, more like the timing is not pulled back for some reason.

I've almost convinced myself that the computers are pulling timing back in first (like it does before it shifts) and once it hits 2nd gear it goes like it should. Can't say that I've looked in to it too much, but this is one of the things I plan on taking a real good look when I get the ST2 hooked up. You can pull the bowden cable full tight and it won't make a difference.

Tampa 928s

Humm, when I got this car it would shift at 4,200 due to the owner adjusting the cables. I did a complete intake refresh, including knock, Tps and flappy solenoid; the car runs great but this has me stumped.

FredR

First of all have you checked that the throttle cable is correctly adjusted- i.e. when the pedal is fully depressed the butterfly is fully open? Very easy to get this wrong/miss it.

Beyond that the stock way to set the kickdown is to adjust the length until it aligns with the cup and then back it off either 1 or three turns-cannot remember which. To improve the shift with the kick down still engaged you tighten it aobut 4 turns tighter than the stock setting. This alone will allow part throttle starts in first gear. You should have no problem at all running to around or just over 6k rpm if everything is working OK. Bypassing the kickdown makes the response a little quicker. In this set up the best way to run is ofund when the cable tension is such that at around 70 mph it will pick up when a gentle throttle pressure is applied but anything more and it changes down- that is how I run it.

I do not understand the relevance of Brian's comment about the throttle switch- these are simply two switches mounted in one housing- as soon as the throttle moves away from tickover this switch throws and tells the brain" I am now off tickover do your stuff". Once the slide gets to about 70% open or so the other contact should throw and this tells the computer to go to the full throttle enrichment map which basically chucks an additional increment of fuel to help get max power.

When I got my sharktuner the first thing I spotted was that the full throttle switch was not working so I simply told the system to ignore the full throttle map [just in case the switch came back to life] and tried to tune the map to deliver a 13:1 to 13.5 AFR when operating in the cells that represent full throttle operation. I cannot visualise any interaction with this and the kickdown cable but maybe there is something going on I have not previously spotted.

Regards

Fred