Starts Barely When Gas is Feathered

[bigboostinmk3]

I bought an 89 mk3 turbo a year ago. It is currently at my fathers shop about 100 miles away from me. We have both been tinkering on it the past year. He is a good mechanic but doesnt know this car that well. The car doesnt have exhaust on it because the people we bought it off thought the cat was plugged and cut it off.

We got the car not running so we started at the simple things first. Checked firing order it was messed up so I fixed that and the car actually started when you pump the gas while cranking and feathering it when it does finally start. It runs rough and backfires and sputters and then dies and it wont go higher then 3krpm. The security light comes on once in a while. I dont know if that has something to do with it or not?

Anyway we replaced the fuel pump and filter. Checked voltage to the pump which was good. I then bought a used 90 ecu which doesnt do anything to help the car it wont even start it. Then we replaced the fuel injectors, rail, and FP regulator same thing. What is weird is the car comes alive when u spray ether in the TB. Can I check the codes when the car if not running? How do I check if my AFM is good?? All I know is the spark is good and the fuel pressure is good.

I have been reading and reading on these forums and I came to think it may be a CPS problem or wiring problem just because of all the symptoms people are having. I am mechanically inclined but I dont know where to start. I hate to just start throwing parts on it or put it in a shop and pay for nothing and still have a car that doesnt run. Can someone lead me in the right direction. I have been doing my homework on this thing.:1zhelp:

 

[Zumtizzle]

check timing?

 

[Quin]

Kinda sounds like what my car does if I forget to plug my AFM in (happens fairly often:icon_redf)

 

[Jaguar_5]

Can I check the codes when the car if not running? How do I check if my AFM is good??

Yes.

I would definitely check your timing, however I would be suspect that if your "car comes alive when u spray ether in the TB" then you may not be getting fuel into the combustion chamber.

To test the AFM;
Air induction system:
http://cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=1

 

[Poodles]

check for codes...

also before you try it... DO NOT CLEAN THE AFM!

 

[bigboostinmk3]

I cannot check timing because it wont stay running long enough.

 

[Fozbo]

Check the physical timing of the engine (actual piston position, cam position, timing belt tension). Make sure that the engine is physically "in time". Set the CPS to the correct position according to the links below. This should get you running enough to get the timing to exactly 10 degrees BTDC (you might need to get someone to help you by keeping the car alive as you are messing with the CPS).

General info:
http://www.cygnusx1.net/Supra/techtips.aspx

Repair manual:
http://www.cygnusx1.net/supra/library/TSRM/mk3/

Timing belt specific page:
http://www.cygnusx1.net/supra/library/TSRM/mk3/manual.aspx?S=EM&P=22

Cam position sensor specific page:
http://www.cygnusx1.net/supra/library/TSRM/mk3/manual.aspx?Section=IG&P=21

 

[Poodles]

oh, and...

CHECK FOR CODES

 

[bigboostinmk3]

one more question. If I get a lexus ls 400 AFM do I have to get 550cc injectors, or can I run it with the stock injectors and stock turbo? Will it cause a power lose? When I set the timing does the diag box have to be jumped?

 

[Fozbo]

The lexus afm and 550cc upgrade is a whole other can of worms. Search around on the forums and there will be some threads to surely pop up.

Yes, you need to jumper the diagnostic terminal like the write-up says in the link above.

Also, you might want to do what Poodles is discretely trying to mention; check the codes:
http://www.cygnusx1.net/Supra/TechTips/engine_error_codes.aspx

 

[Poodles]

I swear it's like pulling teeth...

Any computer controlled car is considered "smart" in that it usually knows what's wrong in some way or another. One only has to ask it...

 

[bigboostinmk3]

Ok I will check the codes and go from there

 

[bigboostinmk3]

today i checked the car out and the only code that came up was a 51. which is the ac switch and tps. I dont even have the ac hooked up. anyway I did an ohm test on the cps and the resistance was 238 when cygnus says it should be 140-180 ohms. Could this be my problem. I also checked the timing and the physical timing was right on the mark TDC. The cps marks were lined up fine also. Where do I go from here?

 

[Poodles]

sounds like the TPS to me then...

 

[shaeff]

http://rob.carlile.home.mchsi.com/lexus/lexus1.htm

 

[bigboostinmk3]

Could the tps stick open and cause it to act this way. or is my cps bad with the resistance that high. Also I forgot to mention this car has a factory alarm system and when u crank it the security light stays on. Now the car wont start at all. Does the security system cut out spark because i know we have good spark to all the cylinders? I am going to test the tps sensor next. In the mean time I probably will try to find another cps for a reasonable price? Any suggestions