MT LT10S problems - ratchety after wouldnt start
 

So be prepared for a lengthy explaination.
To start, I have an 87 TII that's decently modified. I drove to class the morning and everything was fine; ran great. After class 3 hours later I try to start her and she would just crank but wouldnt turn over. All electrics worked ect and found that my ecu would not turn on. So I check the pink and red wire, found the red wire was at 8 volts and the pink was at 12 when the ignition was turned on. 5 minutes later the red came back to full power at 12 volts.

Ecu turned on at this point but she still would not turn over. I jumped the battery even though she had a charged battery. She started right up and drive home after I let her idle for a while. She drove perfect just like before. I try to drive to an appointment that I had this evening and it just became extremely ratchety and damn near undrivable after a couple of minutes. I'm thinking that it is an ECU issue possibley with the TPS. I don't know if my ecu got flashed or what.

I'm planning on taking it to a shop with the software for the ecu and seeing what they can do. I'm not software savy. Do any of you guys have an idea what might have happened/how to mend this? I need my car seeing that it's my daily.

Any insight is appreciated!!!

Also, here is a video clip of the issue: http://www.youtube.com/watch?v=ZCRDz...ZqbyypyCUTIEo=

Sorry for the quality, it's not the best sound but you can hear it.

check the voltage within the ECU while driving, if it's low again then you have a power delivery issue with the car between the battery and the rest of the electrical system. a main power feed doesn't drop to 8volts with a charged battery for no good reason.

What is the best method to monitor the voltage within the ecu while driving?

Check ur fuse holder for the main ecu power ,I've seen them corrode and make a bad connection at the fuse.

the egi fuse?

with the handheld or laptop software, there is a voltage display which is derived from the red feed wire.

Alright, the software is in the mail currently so /i have to wait for that.

Download it it's free

I also do not have a laptop with a 9 pin port. Is there an adapter that is available? I have the microtech adapter but thats 9 pin to 9 pin

radio shack ,best buy, any electronics store sells the adaptor, usb to the microtech but u need the mt dongle.

Dongle? I have the female to male adapter that came with it with microtech labeled on it if that is what youre talking about

So I got the software running, This is at idle. I noticed that it says my TPS is at 25% load - not sure thats right, voltage is pretty damn close to right, idles good... any ideas?

calibrate TPS , no1 issue, and voltage should be about 13.8 after the alt has turned on ( some installs may require a rev )

Going to calibrate the TPS tomorrow and it looks like i'mj going harness diving.

What would cause my TPS to suddently be off? (and thus the bucking i hope) I mean shit, worked fine this morning then bam, shittyness. :P

do you still have the wax cam hooked up ?
needs to be deleted for microtechs
else they will idle on the running load maps and lack the accel pump function for off idle throttle

edit : i mean , pull the cam right off the throttle and wire it out the way
with only the coolant disconnected they will still push the tps cal around

I'm not sure bump. I bought this fc a month ago and am relatively new to rotories in general. I'm assuming that it has been deleted since the previous owner squeezed every little pony out of her and she has run perfect until now.

you will have to take off any top mount and find the wax cam mech on side of the TB , it has a piston that pushed on a cam mech , which pushes on fast idle
dial the cam mech out away from the piston , and you will note it no longer pushed on the throttle link as a fast idle
use baling wire or a zip tie around the throttle dash pot to tie the cam up in this no engage position

beyond that, you can have issues with sticking dash pot
(( delays throttle closing on the primary link side ))
and it may also pay to undo the base nut and wind it back a turn so the throttle shuts to the same spot everytime

also give the linkage a check for binding
,, sometimes people fiddle with the secondary ( opening ) delay dash pot adjustments
( on other side of TB )
and over playing the spring and nut can amount to a linkage that closes poorly

keep in mind that on s4 ( and s5 narrow range tps ) the TPS is at 100 % signal at only 25 % thottle blade position
so small amounts of inconsistancy in the closed throttle position can have large % changes on the screen output

also keep in mind that the TPS cal can drift on some TPS' with temps,, and so calibrate for the asterisk and then push a percent or two more ( still witihn the asterisk calibration ) to give yourself a window to catch the drift

So when i barely tap the throttle, not even 20%, the tps shoots to 99%. The ecu is getting full power as far as i can tell. going to adjust the tps tomorrow in the shop

So I drove it to the shop which is down the road, checked voltage after a bit of driving at it was at 13.3 volts which is ideal. Now, it just seems that the TPS is the issue unless a wiring problem shows itself (Or I could have misread the DMM - don't know how but it happens)

I also noticed that when having the bucking issue, my AFR was dropping from a steady 19 (when driving fine) all the way down to 14.7. Would a uncalibrated TPS cause this?

it would take less time to go out there and tweak the tps than it does to type it out and ponder the reply

do it

I don't have my tools at home, they're at the shop so I can't do it until tomorrow.

Update: Went to warm up the engine and ecu was getting only 5-8 volts again, going to find that shoddy connection to the battery this weekend then calibrate my TPS after that.

i have never noticed the lack of pump1. i run mine with the TPS loaded but have the matrix maps tuned for idle, i just tweak the timing maps when i need to run it through an E test. but the pumps both work fine even with the TPS never touching idle..

i got sick as fuck of the TPS always bouncing one way or another out of calibration because these TPS are hot garbage in a small plastic box.

technically you don't need a TPS at all unless you want an idle down mode for emissions, on the street i just keep my timing up at 17* advance at idle. it gets a little warm but it's a rotary, they do that.