RT142 running badly, now won't start. what do?

[roadsailing]

Hi all,

was driving home on Wednesday, car started shitting out, hesitating, being doughy etc so i figured it was out of petrol. managed to roll into a servo and fill up, drive the few kilometres home and parked it, driving to the gym about an hour later it started doing it again, symptoms were:

low on power, would die when i put my foot down, drove it into the garage and had to repeatedly stab the throttle to keep it running.

i splooged RP7 into the TPS, TPS connector and the flap airflow meter connector, this either made no difference or made it worse. problem seemed to get worse, will either start and run really rough for a second and then die or not start at all.

so far i've tried starting it with the TPS dosconnected, didn't make a noticable difference, neither did unplugging the AFM (need to do this more systematically)

don't think the fuel filter in the engine bay is clogged, i cracked the outlet banjo bolt and it sprayed fuel on the rag i put over it.

don't think the engine is mechanically bad, sounds like it wants to run, turns over fine but there must be an electrical gremlin somewhere, no water in the oil, no oil in the water but this shouldn't stop it from running anyway.

next plan is to see if the fuel pickup is blocked with some shit, hope i don't have to drop the tank.

what else can i check? until Wednesday the car ran perfectly.

[CELICASUPRA7M]

Do they have a check engine light like the 22re in a ra65? may be able to flash fault codes if it does.

[roadsailing]

don't remember the check engine light flashing, i think there is a diagnostic port, not really sure where it is, couldn't find it when i was trying to set the timing. looks like its the airflow meter, it will start and kinda run with it unplugged, can get it to a fast idle (or faster) by careful manipulation of the trhottle, plug ther AFM back in and it runs bad and stalls.

[CELICASUPRA7M]

have you checked that the flap in the AFM moves smoothly? i'v seen camry ones seize up.

[roadsailing]

yeah i had it out to see if i could get inside, moves pretty easily and you can hear it slam shut when the engine stalls. might take it apart and blast it with RP7, dunno where the resistive tracks are though, the bottom panel unscrews but there are no screws on the top.

[roadsailing]

pulled the lid off the AFM, i can start it and make it idle by pushing the wiper forward (forcing the flap more open) and can get it to rev up without hesitating, this leads me to think i have an airleak somewhere.

[roadsailing]

replaced engine bay fuel filter, no change. rear spark plug hole seemed pretty oily but that could have come from anywhere. i dropped all the water out of the cooling system because it felt like the hoses were full of cornflakes and the water that came out had some white froth on it, when i9 started it up (fingering the AFM wiper to make it run ok) white froth appeared in the radiator spigot, what does it all mean!

[roadsailing]

Just checked fault codes, one blink repeating meaning no codes. stupid thing.

[CELICASUPRA7M]

wonder if your intake manifold gasket has had it? be unlikely tho. do you have some brake clean or aerostart you could spray around the mani and see if the engine revs up ?

[roadsailing]

i tipped a bottle of water over the inlet manifold, have checked for loose vacuum lines etc, no change to revs.

I loosened off the AFM spring massively so it puts out the right voltage to fool the ECU to make it run properly so it will idle without touching it, just drove backwards and forwards and it has no power, only thing i haven't done is dropped the tank and checked the pump strainer, i took the sender out and the fuel is clear, no obvious shit on the bottom of the tank.

starting to think it isn't a vacuum leak either, any leak should make it idle fast and it idles the same as ever.

[CELICASUPRA7M]

you said unplugging the tps made no difference? maybe you need to look at that, could grab a few things from the wreckers and try your luck haha.

[roadsailing]

the TPS is just a closed throttle and a WOT switch, its more a "throttle position switch" than a "throttle position sensor"

might have to take it to a mechanic which i'm really not looking forward to.

[CELICASUPRA7M]

oh ok, if it revs fine while you manipulate the afm then the fuel pressure should be ok, which rules out pump/filter/tank.
interesting.

[roadsailing]

i dunno, it suggests to me that the fuel pressure may be too low, and manipulating the AFM it masks this, for rough example if the pressure is half what it should be, but I push the AFM to force the injectors to stay open twice as long it will keep running. this doesn't really explain why it won;t run under load and a few other things though.

[maccac__1590]

so the spark side of things is deffintly good??

try this
33volumeai.pdf