Car troubles =[
 

I have and 87 supra turbo which is runing like crap right now and i need some help. This is what happens when im driving ill get out of first then if i try and go a little faster and my car jerks and dont really go anywhere till i get boost witch is about 3000 RPM then it runs ok but when ever its under stress it just starts jerking its bin like this since i bought it. what could be my problem. i also just hallowed out my cat on the down pipe becausse it was clooged i also found out that my downpipe only has 2 of the 3 nuts and where it connects from the main cat it only has 1 bolt. is it because theres not enough back pressure or off timing i have no clue and i need help. What could it be. =[

PS Anyone on these forums live in Fall River, MA???

Boost leak?

no it cant be a boost leak becasue i get all 7 psi and when i do get boost it runs way smother i think its becasue my exhaust dont have enough back pressure before my turbo spools

Check spark plugs and wires, any oil in the spark plug gallery, check the AFM, check the connection to the AFM, clogged injectors, maybe timing problem, vacuum leak?

i think its ether a timming problem or a vacum leak. But will having no back pressure cause this? Also how does a car run off timming?

previous repair or jump a tooth on the cam due to a faulty tensioner....

or maybe its the same illness this person has with its car....hehe..check it out..

http://break.com/index/deadcatcar.html

I know enough about turbos to tell you that just because you get 7pounds boost and it runs smooth under full boost does not mean you dont have a leak in the system.

I will admit however that I have little knowledge into the turbo Supra so I probably cant be much help but let me offer at least a little advice. When I buy a used car, I spend at least the next 6 months fixing it. And when I say fixing it I mean everything. Missing a screw in some random interior item? I find the right kind and replace it. Im just that way. When it comes to engines, they really do rely on all their systems working together properly. One system out of adjustment or not working CAN and WILL cause other systems to stop working properly.

If your struggling to find whats making your car run crappy, start fixing things you can see that are wrong (like your missing nuts and bolts on the turbo system), and eventually if you keep swingin' you might just hit the nail on the head.

i think i narrowed it down to a dead MAF or bad O2 sensor. i cheacked everything else and they cheaked out fine. eccept the MAF when i unpluged it it didnt do anything it didnt make my car run shittier im thinking its dead. Also when i pulled off my filter there was somekind of liquid coming out of it. Does anyone no how much i should expect to pay for one from a junkyard or toyota?

PS i pretty narrowed it to this becasue my car is runing extremly rich

The turbo is your back pressure...You could disconnect the downpipe and it will run fine.

It can be lots of things causing this, I would check for codes and timing and look for leaks in the IC pipes, couplers, IC, 300 pipe and intake.. here is a how to leak detector.
http://www.vfaq.com/mods/ICtester.html

Here is a TSRM.. codes are under EFI
http://www.cygnusx1.net/supra/library/TSRM/

Theweezle is correct in saying you can still hit 7psi with a large boost leak. The turbo will just have to work harder and pull more air through the AFM to maintain pressure. This excess air through the AFM will trick the ecu into thinking your flowing more air into the motor. The ECU will add more fuel to compensate, causing a rich scenario.