7M-GE Stalling

**smellyhippy** · 23-06-2010, 11:02 PM

Hi guys, still trying to get my Supra running right. Basically it barely idles, won't hold a steady rpm. If I touch the throttle and back off, the revs drop very low and then go back up for a second and keeps fluctuating between that, or drops too low and stalls. The more throttle I give it, the worse this is.

This is all since replacing the head gasket. The plug for the TPS was rooted, but I've fixed this now.

**Gary** · 24-06-2010, 01:05 AM

sounds like timing! mine was similar

need to make sure cam pulleys and crank are in the right position first, then when they're good you need to install the dizzy making sure the little cog meshes with the bit on the cam just right. i didnt know how to do it efficiently - there is a mark there you need to line up, but it didnt work for me most times) so i kept trying till it worked (ie when it didnt, i turned the crank by hand until cam pulleys lined up with the marks on the inner timing cover, guessed the right position on the dizzy, shoved it in and tried again)

once it starts and runs, turn the dizzy gently by hand till its running smooth, whip out the timing light and get timing set properly. or take it to someplace that can

TPS misalignment could be causing dramas too, i think you need a multimeter to do it right

**smellyhippy** · 03-07-2010, 06:25 PM

Have had a lay around adjusting the dizzy, but today had the time to take it out to do it properly. I have set Cyl 1 at TDC, but cannot for the life of me find how to set the MX83 dizzy right before I put it in. The best I've found is this link: http://cygnusx1.net/Media/Supra/Libr.../IG/IG_019.gif
But I have no protrusion on the gear and no real noticeable grove, two smalls ones though.

**woggin** · 05-07-2010, 01:21 AM

could be a leak between the AFM and the throttle body, 7m's arent happy at all when there is an intake leak!

i have ALOT of spare 7m bits, basically all the electrics from the head, so if you want to borrow some parts for diagnostics, am happy to help!

**Jin~Jah** · 06-07-2010, 07:47 AM

Originally Posted by smellyhippy

Have had a lay around adjusting the dizzy, but today had the time to take it out to do it properly. I have set Cyl 1 at TDC, but cannot for the life of me find how to set the MX83 dizzy right before I put it in. The best I've found is this link: http://cygnusx1.net/Media/Supra/Libr.../IG/IG_019.gif
But I have no protrusion on the gear and no real noticeable grove, two smalls ones though.

Pop the distributor cap off, and make sure the rotor is pointing mostly at lead #1 when the engine is at TDC - that should be enough to get it running a bit more smoothly and get a timing light on it!

does the idle change at all when you rotate the dizzy? I had to do this about a week ago with the 7mgte in my cressida - took 3 goes to get it right, and each time it would run slightly better as i got closer to the correct setting.

do you have (or have access to) a timing light? it really will help a lot here, the marks aren't always easy to pick, AND with a 7m, when you put the dizzy or cam angle sensor back in, it rotates slightly to mesh with the gear on the zorst cam. Toyota specifically designed this just to annoy future enthusiasts.