il clean mine agian but im sure it was doing the same thing whith mine unpluged

i did fix the broken wires at the cas plug and restabed the cas but still the same thing il reset my timing and see if it will help, the car seams to be pulling stronger tho. if i cant find this prob in 2 weeks im storing the car for winter and getting a maga squart it comes with a new 2 bar mapsensor and it will solve the prob, and like some one stated creat some new one il keep you guys updated as to what i have found

 

well here's an update i fixed the cracked wires to the cas and after work i had sameer come and help me tonight at 1am lol, we took for a ride and reset the timing of the leading and trailing, then we took it for a test drive same thing 3 gears then no more boosting. i shut it down fire it back up and went to a culdasac and did a donuts so i could play with the boost and it stayed in boost while i was sort of drifting, then as i pulled and made it hold its boost steady it stooped hitting boost. we left it do that so we could do some testing, as once it in this mode even at reving it up at idle will make it not hit boost at all as well, so we unplugged the temp sensor same thing so we plugged it back in. next we unplugged the map sensor vacuum line same thing?.... next we unplugged the 3 wire plug to the map sensor SAME THING STILL CANT GET IT TO HIT BOOST??..... well, only one thing left was the afm. we we unplugged it with the car running, and it changed the way the car was responding, i so final something makes this disappear now we all know the car wont take all the gas i can give it with the afm disconnected but what shocked me was that when we reconnected the afm with the car still running i was able to hit boost once more before it went back in that mode, we we disconnected it once more to see if it would let me boost but it did not,..... so we take it out for an other test drive after shutting down the car, and i got 5 gears of boost i thought it was fixed then no more boost still have the same prob im relay thinking its the bad AFM NOW,

 

i cant seam to find that resistor pack any ware for the 91 turbo is that just an S4 thing? or is there an other name for it, as i might be missing this part causing my probles as well lol

 

I have the same problem at WOT does not rev past 3800 on an S4 Na. I checked the resistor pack and noticed that one of my plugs did not read 6.5 ohms as the others did. It read nothing actually.

Does anyone know off hand how much a new pack costs?

I am hoping the problem will go away when replaced.

Thanks all.

 

So, Ive been busy with school and havent had much time to do much work on my car.
My main concern:
THE PROBLEM STILL EXISTS!

What ive done to try and fix it:
Swapped 3 different TPSs
Swapped 2 different ECUs
Swapped 2 different resistor packs
Swapped 2 different MAP sensors.

Something new:
When I unplug the TPS, the problem use to disappear.
The was the deal until a couple months ago.
NOW, the ECU seems to be unresponsive to TPSs.
It bucks and farts like the TPS is unplugged, even though I have a good, tested,
and calibrated TPS hooked up.

My hypothesis:
The wiring harness is junk.
Somewhere between the TPS and ECU there is a short either causing the signal to ground out giving some signal to the ECU.

My question:
How can I hardwire my TPS directly to the ECU?
What wires go to what pins?
THIS WOULD ONLY BE TEMPORARY.
I plan on building a MegaSquirt system over winter break, but doubt Ill have it in and running by second semester.
I would just like to band-aid the problem so Im not getting 18mpg on the interstate.

Thanks to all,
Alex

 

Any ideas?

 

To to clear any confusion,
I want to see if running wires directly from the ECU to the TPS will fix my problem.
This would simply be a diagnostic, nothing permanent.
What pins for the 3 wires from the short range S4 TPS go to?

 

http://www.teamfc3s.org/main/factory...ual/1986_1988/

section 4b
about a 3rd of the way down

 

Thanks for the link. I had already found pin 2G as being labeled TPS,
but which of the 3 wires of the TPS go to this pin?
Where do the remaining 2 wires go?
+ & - ?

 

no idea, I have the same issue as you do, and in the midst of fixing it as well :/

 

.

 

So,
The right wire(green in HAILER's diagram) goes to 2C which is ground? Could I just ground this at the motor?

The Left wire (Blue) goes to Pin 2A which is V-ref 4.5-5.5V
Is there anywhere under the hood I could splice into a 5V source?
Or should I just run wire from the ECU?

The Middle wire (Red) goes to 2G which is labeled as TPS in the FSM?
I plan on simply bypassing the factory wiring and running new wire directly to
the TPS.

 

if you're running one wire to the ECU already, why not run 2? and the ground could be grounded anywhere

 

Kinda what I figured. I should have that done by this weekend. Will report back afterwards.

 

Soooooo, I hardwired the TPS to the ECU, bypassing the the factory harness. This improved drivibility, but did not solve my problem.
I have officially thrown in the towel.
Time for Megasquirt and a new wiring harness!
Hopefully this thread may solve someone elses troubles!

 

I know this thread is dirt old, but just in case anyone else is having a similar problem,
I replaced my wiring harness with another used NA harness and problem solved.
My old and crusty wiring harness had a short somewhere that was preventing my secondaries from firing.
After replacing it, my car runs fine.
Hope this helps someone somewhere down the road...

-Alex

 

Appreciate the followthrough, I'm sure it will help someone.

Sounds like a commercial for Slevin FD, who's thinking about offering a harness rebuild service. Seems like tending to the harness is almost as important as replacing seals when it comes rebuild time... Makes since though, twisting up that crispy critter to get it off the motor probably pushes a few marginal connections over the edge.