I have tons of questions, I've searched and got most of my answers. Great Forum!

Any way I bought the microtech LT8 to go on the '88 TII. I have HKS sport Turbo upgrade and somewhat preped motor w/ 25K on it.

I pulled the intake manifold off to install new injectors and fuel lines. Anyway when that happened I ended up replacing everything worth replacing.


1) I did the throttle body mod, no problem. But I was looing at the TPS. I don't understand how the TPS works. It looks like that after the throttle is opened about 25% the plunger on the TPS is fully extended. How does the TPS measure the other 70-75% that throttle can open?

2) Is there a reason people aren't having a welder seal the secondary shaft holes that are left over from the secondary throttle blades?

3) Has anyone w/ standalone EMS used another brand of TPS? Like Ford?

4) I've heard some stories about failure of Walbro pumps, Anyone have a horror story to share?

 

1. You are right, the stock TPS doesn't travel the entire distance that the plates travel. The stock ECU gets input from the AFM which measures the air intake, as well as the intake air temp sensor and the vaccuum/boost sensor. Somehow, it all works out for scheduling fuel.

2. I used JB Weld and a bolt that fit in the hole. Much cheaper and equally efficient then welding aluminum.

3. I have a Haltech E6K and it comes with its own TPS. Haven't tried using another. Did the microtech come with its own?

4. No experience with this pump.

 

The Microtech uses the stock TPS. Because of how the Mirotech uses the TPS signal there is no problem with the stock sensor, and yes you are righ it is not a full range TPS. Series 5 cars do have a full range.

Most people tap the shaft holes and plug tehm with a couple bolts.

I have seen nothing but good things from the Walbro.

 

well i jsut installed my lt8 into my 89 tII. my car had 2 tpses. here s write up on it.http://www.br7racing.com/tips.html
as for the remaining holes i just used jb weld also. the only thing i have heard about the walbo pumps is that thye loose pressure in higher rpms on high hp applications. im not to positive on when they start dropping psi but i think its around 375 to 400rwhp ish. let me know if u have any other questions

 

hey, so you got that tps working finnaly? Did you have to get a bracket made up for it?

 

So the microtech uses the stock TPS? How does that work out since I know that on my s-afc it reads throttle to be 100% with your foot on the gas at all most of the time. Is that just a poor reading from the s-afc or what?

 

The TPS is only used to tell the ECU when the throttle is closed. It's not used for anything else.

 

When driving down the highway, if the TPS doesn't move for 3 seconds, the ECU will start sampling the exhaust through the O2 sensor and start leaning out the fuel mixture to achieve a more economic mixture for cruising.

Kenteth, I'm going to send the throttle body and TPS to a guy who will make the bracket.

 

Stock ECU has a closed loop function, the LT series doesn't.

TPS is used just like NZ said. All other factors are used for generating the fuel delivery. IE temps, pressure (MAP), etc etc...

If your stock sensor is working fine without any dead spots (if it reads some whacky voltage), then keep using it.

 

I was refering the the stock TPS and ECU for the closed loop, not the LT8.

 

The microtech uses factory sensors. You do run one manifold hose to the ecu though.

 

So are you saying the microtech does not do throttle/accelerator pump correction?

 

Can we see pics of your HKS sport turbo kit?

 

Theres a partial truth to that. There is a high pressure and low pressure 255lph pump. There is also a 190lph pump. People on ebay may be selling the 190's as 255s.

 

All you can really see is the Turbo, which looks just like every other T04B. It has a cast iron manifold and HKS wastegate. But you can't see either very well.

maybe when I get everything installed it'll look better

 

If it helps (or not):

I have a Walbro 255 lp/h pump in my car now.

Just the other day I ordered a Nippondenso (Supra) fuel pump for the car. Why?

$100 bucks extra over the Walbro is worth the peace of mind knowing that my pump provides me perfect consistancy and won't die any time soon

 

The Microtech has 2 throttle pumps, one for off idle and the other for higher load throttle delta's.

Daniel

 

"higher load throttle delta's"?

 

Sorry, I was referring to the stock TPS. The S4's TPS only measures the first 10-15deg of throttle opening, so it doesn't matter what ECU you connect it to, it'll be no good for this role.

The Microtech can use either the MAP sensor or the TPS to do this. I believe the MAP mode is the default setting.