1986 1st Supra Running Poorly

[cre]

http://www.cygnusx1.net/Supra/Librar...spx?F=1708&P=2

[dlfred]

There is a broken wire on one of the connectors, VSV I think the filter is broke of it and now there isn't a bit of wire to repair the connector.

As far as the broken wire, I was thinking that I could take a straight pin and connected the wire and connector using the pin in the center and solder the area. Sounds pretty cheap, I haven't figured out how to push the remaining wire out of the connector and go at it that way. I am open to suggestions, please.

thanks

[dlfred]

Originally Posted by dlfred

Starts up easy and does a cold start high idle of about 2300 and only drops to about 1300 rpm at warm idle. Wack the throttle and the idle will drop to about 1000 rpm and then very slowly climbs back up. Taking off from a start it doesn't seem to pull very hard, while accelerating if you roll back off the gas a little it seems to clean out a little and pull smoother. If you stay in it at about 4800 rpm it starts to pull a little harder and more smoothly. It doesn't smoke or knock at all.
The code it's spitting out is 52, have not tested the Knock Sensor yet. The cruise doesn't work and the fuse is good.
Thanks for your help.
Dave


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So the car is back together and running much better. The cruise control even works. The vacuum lines where messed up so that helped but I still hear a vacuum leak. The motor started easily and had a rough idle for a while and then would settle down and idle at 1100 or so. It still doesn't have any snap to the throttle. It pulls better than before and seems to do it pretty smooth from about 2500 up. I have that one sensor, a vsv I think, has a broken wire and none of those type sensors have that filter on the end of them.
As far as the air leak, I am wondering if it is the mani, I sprayed a little brake clean near the front of the mani and the idle definitely changed.
Do these carss have manifold issues, the gasket was new so I reused it dry. I did not take off the bottom half, the real manifold. Oh well it runs OK, I could use a suggestion or 2. Oh and no engine light.

Thanks

[dlfred]

Can the car run correctly without the VSV connected? I have a broken wire right at the connector. It will be a hassle to repair the connector. Any tips?

It still doesn't have any snap to the throttle. It pulls better than before and seems to do it pretty smooth from about 2500rpm.

[MA70-3.0GT]

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]

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.

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]

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]

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

[dlfred]

Can someone please tell me where in the shop manual you can find the factory settings on the screws on the TP? The stop screws and the one on the diaprahm do-dad? I appreciate it.

[cre]

You mean the TPS, I presume? It's in the EFI section under Throttle Body and then Throttle Position Sensor.