testing tps without starting car
 

well it seems that no matter what i do i can't get my car to run. its really driving me nuts. i can get it to start if i do the oil in the lower plug holes. but everything in the car checks out as good, even the water thermo thing so dont even suggest telling me to test it. anyways since it is a bitch to get started and warm up i was wondering if there is another way to test the tps. and also will a faulty tps keep the car from starting? im not sure im out of ideas and since this is my dd i need it fixed asap.

Yes you can test it without starting the car. If you still have the fast idle/thermowax system, you will need to rotate the little arm upwards to disengage it.

But I doubt that's the reason why your engine doesn't even fire up. Is the engine flooding out? What's the history of the car? How old is the motor and when did it last run?

its got the tb mod so none of that would be an issue.

the engine is flooding out. not sure why but it floods insanely fast. first turn of the key. its a TURBO SWAPPED base s4. no emissions. the motor is fairly new, just got done breaking it in on a "fresh" rebuild. and it was running fine until one day i was gettin on the freeway and got on it. i hit a 6k roadblock and couldnt go passed it. ever since then its been like this. tried 3 different ecu's and not a single difference.

it seems to want to start with the tps unhooked. but still didnt take off... so anybody have ideas? or is this going to end up being another thread where rx7club doesnt want to help?

The TPS has ZERO to do with starting the engine.

And just for grins, the AFM has zero zippity to do with starting the engine.

And don't dare ask if the alternator has anything to do with starting, please.

Did I mention checking out the water thermo sensor at the ECU and seeing what voltage it reads when hot? When cold?

Sounds more like a blown engine/dropped apex seal. We assume the TID did not come off at the turbo nor the ducts that leave the turbo, ducts at the intercooler didn't fall off, small tubes on the intercooler did not fall off. Nope, blown apex seal it is.

^ +1

I agree a compression test is in order.

wierd cause with the tps unplugged it started right up.

also its got good compression. already checked that. thought it was an issue but nope. and also while deflooding it you can hear it and it doesnt sound like a bad apex seal.

when it cools down, its like 100 outside already, i will check the voltage of the waTER thermo sensor. anyone know right off hand what pin it is on the ecu?

and also the gasket between the turbo and downpipe is gone. not sure what happened to it but its gone. will this affect anything? like give the o2 sensor false reading? cause after i start it and let it warm up i hit the gas and seen all the extra oil i stuck it come out of here as smoke. and its a lot.

Pin 2I. With key to "on," .4volts to 1.8volts when warm and basically 2 to 3 volts cold.

well i went to test pin 2I and this is what i came up with
its roughly 95* outside, not sure if that affects it. but while cold it was about1.5vdc and once warmed up it was .4-.5vdc. so these numbers appear to be ok right?

also i might add that while attemping to start it would just crank and crank and crank. so i pulled olugs de-flooded it and added some oil and it started within half a second from me turning the key.like nothing

.4 to .5 volts warmed up is just right!

but what about the cold readings? my issue isnt anything to do with running. it seems to run like a top. im just having issues with starting it.

If the engine was started up prior to the testing and therefor warmed up the coolant then your cold start reading might not be fully accurate. Pehaps letting it sit overnight would be best before taking an accurate reading.

the engine WAS NOT started for about 24 hours prior to me testing the voltage "cold". which was 1.5vdc. now is that what it should be?

after i recorded that number i started it and let it warm up. this was the first time it ran in a 24 hour period.

Service manual says .4 to 1.8 volts when warm but with the warm temps you reported that would affect the cold start reading. How much? I do not know.

ah. well since my cold reading is in the same range the FSM says it should be for hot this will explain why it always wants to flood when starting. doesnt seem like that bad of an idea to replace it, its only about 15 bucks. so ill swap tht out and see what i get. also ill try again when its closed to 75-80* outside later tonight..

well new thermo sensor did nothing for me. everything is in good working order but the fucking car wont start still. i see why people put v8s in their car. at least on the v8 forums they can get help

satch i just want to confirm, where are you getting theese numbers, or is it just an expierience thing?
the FSM (F1-80) states pin 2I with the ign on it should read 4.5-5.5v and says nothing on wether the engine is warm or cold.

i searched and searched and couldnt find those number you speak of. but i believe that is prolly what i want to be seeing with the engine cold. not the 1.8vdc that i am. i think possibly i might have got the wires mixed up cause i had to swap out the old plug. can someone post a picture of their plug so i can see that i got mine hooked up the right way?

Below is for S4 NA. Turbo has the remark "Warm Engine."


http://img844.imageshack.us/img844/9...upinout.th.png

so can anyone answer me? is the 1.8vdc that im seeing while the engine is cold good or bad? should it be higher or lower?

You could disconnect the plug from the thermosensor and unscrew it and place the sensoring part in a cup of water that is 68 degrees and then measure its resistance as it should read (2.45). If the water in the cup were heated to 176 degrees then the resistance ought to read (.32). You can't get the water to -4 degrees but if it were possible the reading would then be (16.2). This comes right from the FSM. Nothing more, nothing less.

o S4, S5, turbo, N/A, im a moron!

the sensor is brand new. i dont see a need to measure the resistance. all i really wanna know is if my reading of 1.8vdc is what it should be cold. if not then i have to figure out why... ugh i really just want my car to be driving. nobody has any suggestions for gettin it to start? everything is checking out fine but it just wont start.

TPS have NOTHING AT ALL TO DO WITH AN ENGINE STARTING.

There is NO given value for the output of a cold water thermosensor BECAUSE what is COLD??? 80*F, 40*F, 77*F????????????

There is in the FSM a procedure for checking out the water thermo sensor by ohming it out at different water temperatures. See book. The resistance equates to what the voltge will be ....more or less. There's a little more trickery involved than I =E/R stuff.

That said, somewhere in the past I logged on this forum the vdc values of the waterthermo sensor at different water temperatures. I used my RTEK 2.0 with PALM to look at the water temperature and used a Fluke backprobing the 2I pin in the middle pulg. I made up a list of different temps vs voltage.

The FSM gives the temp for a fully warmed up engine BECAUSE they put a approx 180*F thermostat in the engine and know what a fully warmed up engine temp is so they can put down a voltage for that temperature which is ???? 0.4 to 0.5 vdc or whatever the FSM says it is.

The volt and a half your getting sounds reasonable to me given this is summer and all. Cold engine.

Get someone to pull the car around the block if you Know you have spark and fuel. That's a first time I ever suggested that on this site.

so your solution to my starting issue is just have someone pull me aroudn the block? that really doesnt help me any considering i can get it to start in teh drive way with oil in the plug holes. i wanna be able to hop in it and turn the key and be on my way. but i have no way of doing this because i have no idea why my car is dumping tons and tons and tons of fuel into the motor