1986 1st Supra Running Poorly

[dlfred]

The screws I was talking about are on the firewall side of the TP, opposite of the TPS. One is on the linkage and the other on a diaphragm attached to the TP. Some type of stop screw I think.
I cannot get pics today but if that is what is needed, I will. The guy told me he adjusted the idle using them. I believe that is not the correct so I wanted to set the screws back to spec?
Thanks

[dlfred]

Can a clogged CAT make the car stumble on hard acceleration? Not real hard, half throttle and up. I replaced plugs (NGK) and set the TP values(ohms). It runs better but has a rough idle and will not pull hard unless you gas it easy.

Appreciate your help. And hey if I am doing something wrong in my posts please let me know. First time forum user. Thanks

[dlfred]

I still have not gotten the car accelerate hard. It will go just feels like a 4 or 5 cyl most of the time.

Will a leak in the hose coming off the front of the valve cover, vent. hose #3, cause running issues?

I have read several places suggesting removing the egr and related lines. Is this a good idea? I have no emissions testing in my area.

The car seems to idle higher and better once it warms up.

[dlfred]

Look,
I apologize for any incorrect "Forum" etiquette that may have caused any problems with my post. It seemed pretty lonely, so maybe I was just re-hashing things too much. Either way you guys helped and I appreciate it.

The car's biggest issue was the injectors being clogged due to sitting for over a year. (I may have failed to mention that). I read somewhere to run the injector additive, I used Lucas, and after 2 or 3 tanks the car runs much better. It stills runs a little rich below 3K and will not accept full throttle consistently, but it's getting better the more I drive.

If my check engine light is not flashing anymore and the EFI has been cleared, does that mean that I have no error codes? The light works fine, just wasn't sure what came first the flash or the jumper?

Thanks- I love this car.

[btwilson86]

So I re-read your thread, and saw you mentioning your distributor adjustment.

I think, since the car is running a little better, that now would be a good time to check your timing. I know that if one of your camshafts is just a tooth off, it will run similarly to what you're describing.

Remove the plastic upper timing cover, and verify that when the engine is at TDC on the compression stroke the 2 cam gear timing marks point straight up, inline with the raised line on the timing plate behind the cam gears. Also make sure your crank is pointed right at the 0 mark. If not, release the belt tension, slide the belt off the cam gears, and adjust as necessary.

Once that's all dialed in, replace your timing cover and idle the car up to operating temperature. You're gonna put a jumper wire in the diagnostic box (like you're checking for codes), hook up a timing light to the no.1 cylinder wire, and set your base ignition timing to 10? BTDC. Make your adjustments by loosening that dizzy bolt and turning it till it's set. Once dialed in, tighten the bolt, remove your jumper wire, disconnect the timing light, and go for a drive.


Let us know how it drives then


Oh, more detailed instructions on checking timing can be found in the TSRM

[dlfred]

Great, thank you so much. I think that the exhaust is leaking at the header flange. Has a little spit sound goin on. I am impressed with the temp while running, regardless of town or highway it stays below the 1/2 way mark. Cool!

[dlfred]

Just so you know I will be following your advice, just have to snag my timing light back from my brother.

[dlfred]

Originally Posted by btwilson86

So I re-read your thread, and saw you mentioning your distributor adjustment.

I think, since the car is running a little better, that now would be a good time to check your timing. I know that if one of your camshafts is just a tooth off, it will run similarly to what you're describing.

Remove the plastic upper timing cover, and verify that when the engine is at TDC on the compression stroke the 2 cam gear timing marks point straight up, inline with the raised line on the timing plate behind the cam gears. Also make sure your crank is pointed right at the 0 mark. If not, release the belt tension, slide the belt off the cam gears, and adjust as necessary.

Once that's all dialed in, replace your timing cover and idle the car up to operating temperature. You're gonna put a jumper wire in the diagnostic box (like you're checking for codes), hook up a timing light to the no.1 cylinder wire, and set your base ignition timing to 10? BTDC. Make your adjustments by loosening that dizzy bolt and turning it till it's set. Once dialed in, tighten the bolt, remove your jumper wire, disconnect the timing light, and go for a drive.


Let us know how it drives then


Oh, more detailed instructions on checking timing can be found in the TSRM

Just wanted you to know. I have been on IR and just now checked cam timing. Right cam off by 2 teeth. Improved performance. Can't thank you enough for your advice.

[dlfred]

Update: The battery would start the car but as time went by it acted like it wouldn't hold a charge. I swapped the battery out and it improved the cars performance. I suppose I could have had a bad cell. The cruise is still not working, I sometimes can adjust the steering wheel and it will work. Any thoughts there? The idle still slowly climbs to 1200rpm after blipping the throttle. Today I will remove all the intake components and check the TPS and ISC. Can all the TPS settings be done off the car? It is running better all the time.

[dlfred]

I am checking the cam timing and I remember reading somewhere that you can look inside the oil filler cap and see the cam lobe pointing upward. I believe that the guys who did the BHG made white marks and a L or R on the cam gears. The issue I am having is that when I line up the painted lines and the crank is on 0, I can't see the upward pointing lobe. The look more closely and see stamped marks at 6 oclock. So my concern here is that somehow the guys have the cams 180 out. I don't even think it would run. I rotated the crank 360 and the lobe still cannot be seen. The car has been running OK just a idle issue.

So here it is.

1) Does anyone know about the looking at the intake cam and seeing the lobe when piston 1 is at TDC?

2) What is the deal with the marks on the cam gear? Painted vs Stamped?