1986 1st Supra Running Poorly

MA70-3.0GT · 04-03-2010, 04:10 PM

IIRC one of those vsv's is to do with fuel pressure & should really be connected, it's possible the whole thing is u/s if the filter is broken off so I'd try find a replacement if possible. As for the broken wire I can't see exactly how it's broken but if it's inside the plug as I'm thinking I'd just shave the side off the plug & solder the wire back onto the exposed connector. Try that first off & see if that improves things.

If you can still hear a vac leak it could be that front metal pipe we mentioned earlier or even the broken vsv, ideally you want a stethoscope or similar to trace more accurately where the sound is coming from. Glad you have it running at least some better anyhow.

P.S. you said the idle changed when you sprayed round the manifold gasket, so that's another suspect for your vacuum leak I guess... are all the mani' to head bolts tight first off with that one?

Oh the joys of using a real computer, I can actually look at longer threads & replying doesn't cause cramp in my thumb!!!

cre · 04-03-2010, 07:07 PM

Quote:

Originally Posted by MA70-3.0GT

IIRC one of those vsv's is to do with fuel pressure & should really be connected

There are three under the intake manifold on the N/A: EGR, ACIS and Fuel Pressure Control.

Both the ACIS and FP Control will affect the engine's operation at higher RPM operation although a defective ACIS system usually leads to crap performance up until right at 4KRPM... it's still worth investigating.

Quote:

Originally Posted by MA70-3.0GT

Oh the joys of using a real computer, I can actually look at longer threads & replying doesn't cause cramp in my thumb!!!

I hear ya. I've been so busy with work that all I really ever have time to check in with is my cell which I've recently replaces with a newer one with no physical keyboard... it's nice though, I can still access the full site and it's MUCH faster.

dlfred · 04-04-2010, 10:24 AM

The wire is broken off flush with the back edge of the connector on the harness side.

I think getting this ACIS system working first may take care of most of the running issues.

The 3 sensors we are talking about, are they only on the NA's?

Would this explain why the car runs on 5 cyl. and the will skip into a 6 cylinder running mode?

Thank you again for your input.

dlfred · 04-06-2010, 07:26 PM

I found a connector at the junk yard for $5. Nice. So the car idles much better but still will not pull under hard acceleration. Roll out of it a little and it feels as though the motor adds a cylinder and pulls smooth. It seems to get better as it gets hotter, not good, just better. I did the vacuum test from the manual and I have vacuum when I shouldn't or don't have it when I should.

Any ideas? Thanks

04-03-2010, 04:10 PM	#1
MA70-3.0GT 12psi boost Join Date: Oct 2009 Location: Crewe, England Posts: 356	IIRC one of those vsv's is to do with fuel pressure & should really be connected, it's possible the whole thing is u/s if the filter is broken off so I'd try find a replacement if possible. As for the broken wire I can't see exactly how it's broken but if it's inside the plug as I'm thinking I'd just shave the side off the plug & solder the wire back onto the exposed connector. Try that first off & see if that improves things. If you can still hear a vac leak it could be that front metal pipe we mentioned earlier or even the broken vsv, ideally you want a stethoscope or similar to trace more accurately where the sound is coming from. Glad you have it running at least some better anyhow. P.S. you said the idle changed when you sprayed round the manifold gasket, so that's another suspect for your vacuum leak I guess... are all the mani' to head bolts tight first off with that one? Oh the joys of using a real computer, I can actually look at longer threads & replying doesn't cause cramp in my thumb!!! __________________ '89 MA70 Supra GT aero 3.0turbo JDM, Rebuilt motor, K&N intake, 3" stainless turbo-back. New turbo and braided line kit... '89 Honda NC27 400, NC23 cams, open pipe, PC36a shock & possibly Showa USD forks... '83 Yamaha 29R XJ750E-II, number 69 off the line, only runner in the country? Original except Koni shocks '95 Honda PC26 CB500R, Winter hack, hateful, trying to sell it I'm not paranoid, they really ARE after me!!!

04-04-2010, 10:24 AM	#3
dlfred 3" Exhaust Join Date: Mar 2010 Location: Georgia Posts: 66	The wire is broken off flush with the back edge of the connector on the harness side. I think getting this ACIS system working first may take care of most of the running issues. The 3 sensors we are talking about, are they only on the NA's? Would this explain why the car runs on 5 cyl. and the will skip into a 6 cylinder running mode? Thank you again for your input. Attached Thumbnails

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04-06-2010, 07:26 PM	#4
dlfred 3" Exhaust Join Date: Mar 2010 Location: Georgia Posts: 66	I found a connector at the junk yard for $5. Nice. So the car idles much better but still will not pull under hard acceleration. Roll out of it a little and it feels as though the motor adds a cylinder and pulls smooth. It seems to get better as it gets hotter, not good, just better. I did the vacuum test from the manual and I have vacuum when I shouldn't or don't have it when I should. Any ideas? Thanks