1989 turbo need help!

cre · 01-22-2010, 09:03 PM

Quote:

Originally Posted by ftwmotorsports

no havent tried cleaning anything yet.

Good.. DON'T! The AFM on the 7M-GTE is an optical unit, cleaning solutions tend to fog the optics and they're not user serviceable!

Quote:

Originally Posted by ftwmotorsports

anybody else have any ideas? The strange thing about this is that when it dies after you boost, you can hear what sounds like a blow off valve coming back through the air filter. Sounds like the compressor surging in a sort, but its not the blow off valve, cause it will do it with it hooked up or unhooked. Also its not the idle air control, we unhooked it while it was running and blocked it, and I feathered the throttle to keep it going, while checking to see if the little orange valve in there was letting boost air creep by. Wasnt it. This thing has me baffled, and the customer is ready to get it back. Thanks for any help!

Ryan

A couple things. First off, half the people out there who run BOVs which are vented to atmosphere have issues with the car stumbling, backfiring and some have stalling issues. This is because the ECU is still expecting the air you just dumped to reach the engine so it's still delivering fuel. This can be tuned out with an aftermarket fuel controller. Oddly, the severity of this varies heavily from one car to the next.

Yes, the whistling sounds a lot like a severe boost leak.. check the usual suspects, this is routine... couplers, BOV, check valves (PCV system and ISC), and manifold gaskets... a leak somewhere further down the line can sound like it's coming from closer to the inlet ad the sound resonates through the piping.

Have you inspected the wastegate and made sure it's not stuck open?

ftwmotorsports · 01-22-2010, 10:29 PM

the wastegate is fine, it spools and boosts normally, its just when you let off that the problem occurs. I opened the throttle blade a little with the adjustment screw as it was totally closed off at idle. It made it a whole lot better and when I test drove it a little while ago it was great, I set the screw out about .020". My mechanic took it out for a test drive to confirm and it died twice on him. So just to test I taped a .025" feeler gauge behind the throttle stop screw and tried it again. This time it didnt die. I will have to adjust the TPS to the blade though. I may try another .010" and adjust the TPS. Ill report back.

cre · 01-22-2010, 10:54 PM

It's supposed to be fully closed off throttle...

Here, read this:
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/

ciao

ftwmotorsports · 01-28-2010, 03:44 PM

we figured it out. We took the IACV apart and its all corroded and rusted inside. It wont move a bit. Does anyone have a good used one they will sell? Thanks guys!

Dakota5605 · 10-20-2010, 03:47 PM

I'm having the same issue with my 87. As soon as you let off the gas pullin up to a red light the rpm's drop way down and sometimes it will recover and sometimes it stalls. I have played with the vacuum lines, throttle linkage, idle adjustment screw and set the timing and still does it. Let me know if fixing the IACV works?

01-22-2010, 10:54 PM	#3
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	It's supposed to be fully closed off throttle... Here, read this: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/ ciao __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar ---> Last edited by cre; 01-22-2010 at 11:00 PM.

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01-22-2010, 10:29 PM	#2
ftwmotorsports Stock Join Date: Jan 2010 Location: wichita,ks Posts: 12	the wastegate is fine, it spools and boosts normally, its just when you let off that the problem occurs. I opened the throttle blade a little with the adjustment screw as it was totally closed off at idle. It made it a whole lot better and when I test drove it a little while ago it was great, I set the screw out about .020". My mechanic took it out for a test drive to confirm and it died twice on him. So just to test I taped a .025" feeler gauge behind the throttle stop screw and tried it again. This time it didnt die. I will have to adjust the TPS to the blade though. I may try another .010" and adjust the TPS. Ill report back.

01-28-2010, 03:44 PM	#4
ftwmotorsports Stock Join Date: Jan 2010 Location: wichita,ks Posts: 12	we figured it out. We took the IACV apart and its all corroded and rusted inside. It wont move a bit. Does anyone have a good used one they will sell? Thanks guys!

10-20-2010, 03:47 PM	#5
Dakota5605 Stock Join Date: Oct 2010 Location: Greensburg Pa Posts: 4	I'm having the same issue with my 87. As soon as you let off the gas pullin up to a red light the rpm's drop way down and sometimes it will recover and sometimes it stalls. I have played with the vacuum lines, throttle linkage, idle adjustment screw and set the timing and still does it. Let me know if fixing the IACV works?