7mgte won't rev past 3k

[cyanide54]

Hey guys,

My freshly rebuilt 7m is idling perfectly, and revs up to 3k quite nicely but when 3k hits, it feels like the motor hits a wall, it stops revving and if I try to give more gas I get the occasional popping sound out of the intake. I have ensured base timing is set to 10* while car is warm with te1 and e1 jumpered, thought maybe the tps was the problem, found mine was faulty and got a new one. I'm also having some trouble getting it set to proper resistance with the throttle open to .5mm, it seems that when it gains resistance it goes from 0 to infinity quite immediately with only a couple thou of rotation in between, is this normal? Any other suggestions for the revving problem are much appreciated.

The 7m got new rings, bearings, crank polish, decked block, shaved head, MHG and a billet compressor wheel in a brand new ct26.

 

[IndigoMKII]

Yes, it's normal. You're seeing it go from 0 to infinite ohms because that's the IDL contacts in the TPS. As soon as your foot moves the throttle, that contact needs to break so the ECU sees you as increasing the throttle angle so it can make adjustments accordingly.

 

[jetjock]

A faulty AFM will limit rpm to 3K. A faulty TPS will not. Course, for the AFM to cause it code 31 would normally be set. As for the TPS resistance, that's normal. What you're setting is nothing more than a single pole switch, as clearly depicted in the service manual.

edit: beaten by Indigo...

 

[cyanide54]

So with the tps set to where it deflects at .7mm, it should be good to go? Will it make a huge difference if it does not have the EXACT values that the tsrm had per difference sized feeler gauges? If so I can cross that off of my list and try something else, MAF?

Edit: roger, will look into maf. Should be ok as it was before rebuild but I'll maybe find a local supra owner with a spare and change mine out to see if mine is faulty.

 

[jetjock]

1) TPS doesn't have to be exact. You could even unplug the thing and other than a wonky idle the engine will run pretty much normal. Any 7M that doesn't has something wrong with it.

2) Check for codes, particularly air flow meter related ones (the engine does not have a MAF).

 

[cyanide54]

Any tips for cleaning AFM? I've heard to use electrical contact cleaner as opposed to sensor cleaner as it can coat certain parts in a film? Should I take it completely apart or just out of the car?

 

[super51fan]

Don't clean a Karman vortex AFM. Have you check for codes as others have suggested?

 

[cyanide54]

car wasn't throwing codes at the time of post but i checked again today after checking out the AFM and its not throwing 24 and 31, I assume one is because I ran the car without the AFM for a minute or so

 

[cyanide54]

Back again guys,

I had an extremely reputable toyota mechanic come to check out the car and see if he could diagnose the problem. He figured based on what he could hear, that the turbo isnt spooling, and is most likely due to the wastegate being stuck open a hair. I could see this being true as I installed the wastegate actuator rod, which was threaded, I very easily could've unthreaded it enough so that in the actuators resting position, it would hold the gate open just enough to keep it from building boost in the turbo. Anyone think this could be a proper diagnosis to the stumble of the motor? Does the ecu expect more air to be jn the motor at certain rpm numbers? Or is it all based on how much air is sucked through the afm?

 

[S.A. supra]

TPS isn't installed correctly, I would guess. Make sure that it's catching the little wing looking thing on the throttle body. Make sure it is loading the spring of the tps. If that makes any sense.

 

[tlo86]

anyone touch at a loose IC pipe yet ;p

wont rev past 3k rpm turbo doesnt spool.. no pressure.. same as when i forgot to connect that last connecter to my 3000 pipe