1986 1st Supra Running Poorly

[dlfred]

Thanks BTWilson I was hoping someone would tell me where that went. Would there be any reason someone selling the car would disconnect it? It could be he couldn't see where it plugged up once he put most of that area together.

Can anyone tell me what he may have done in order for it to run without the knock sensor hooked up? Would this explain the low power as well?

And to Green7mgte, Thanks for the welcome.

[dlfred]

Found a brass nipple with a red o-ring on the side of the block below the intake manifold. Because of the current routing of the wire it looks like I will have to remove the manifold in order to reach the sensor. Any hints or tips on this. It might be a good idea for me to recheck this repair anyway. What do you all think, what would you do?

Thanks

[MA70-3.0GT]

Thats the ks with the red seal. It was probably forgotten when the mani was refitted, i'd pull the thing and reconnect (drain the coolant as it runs thru the mani, also fit new mani gasket for the same reason).

Oh by the way, the cx is a eurosport (ec)! It just soldiers on, all ive done is oil, tyres, cables etc.
Oh and one time the temp gauge was running in the red for 2 weeks or so, i thought it was the gauge regulator which is a common thing, except when i opened the rad to change antifreeze it was dry! (never found the cause, no leaks) So yeah they are tough motors with a capital T!

[dlfred]

Okay, well I guess I was looking for a good excuse to a redo, there are some things left hanging. Should I do anything with the injectors while I am there? The car sat several years but it ran. Any other stuff I should take care of let me know, for sure i will take care of the exhaust manifold gasket. I really liked Honda's Turbo CX's. My family owned a Honda dealership in the 1980's and early 90's.

[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]

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.