Stock 87 7M-GTE possible injector problems

[Firechikin68]

I'm a new supra owner and the turbo i got had been sitting up for a few years and had about 3/4 inch of nasty really thick goo and rust on the inside of the fuel tank. I replaced the tank out of a parts car and got a new fuel pump. And i am still having problems getting the car running. I turn the cam sensor all the way to the left to make it run best which is at about 100-200 rpm and backfiring lightly through the intake. I thought maybe the timing belt skipped a tooth so i checked the timing marks and they all line up. I've got spark. Its not bright blue but its halfway decent spark. The only thing i can come up with is possibly all that gunk in the tank may have made its way to the injectors and clogged them up. Does anyone know a way to test these to see if they are firing correctly and the stock injector size if they are in need of replacement? Or possibly any other suggestions as to what the problem might be? I'm not very good at diagnostics at all. So i am probably going to have to be walked through this, sorry for being a noob. Thanks.

 

[tlo86]

never hurts to have the injectors cleaned and flowtested

 

[3p141592654]

Besides cleaning the injectors, you might want to replace the filter and blow out the fuel rail and lines. You have to wonder what would cause that much goo to form on the tank walls.

 

[IHI-RHC7]

did yu ever remove the CPS?

 

[Firechikin68]

Besides cleaning the injectors, you might want to replace the filter and blow out the fuel rail and lines. You have to wonder what would cause that much goo to form on the tank walls.[/QUOTE

I did all that when i replaced the tank and pump. I don't have a clue what all that goo could have been. You could roll it up into a little ball it was so thick

 

[Firechikin68]

did yu ever remove the CPS?

I never did. All i did was turn it. I just got the car and the CPS bolt was already loose.

 

[3p141592654]

Okay, good. By the way, are you saying it idles at only 100-200rpm? Does it rev, can it be driven?

If the engine runs well enough to drive, you should try to figure out the A/F ratio. Do you have any means to measure A/F, or a gas analyzer?

If not, you could warm it up until its in closed loop and see what the fuel trim works out to be. Gunked up injectors should cause the fuel trim to be maxed out (Vf=5V) as the ECU tries to add fuel to hit stoich.

 

[Firechikin68]

Okay, good. By the way, are you saying it idles at only 100-200rpm? Does it rev, can it be driven?

If the engine runs well enough to drive, you should try to figure out the A/F ratio. Do you have any means to measure A/F, or a gas analyzer?

If not, you could warm it up until its in closed loop and see what the fuel trim works out to be. Gunked up injectors should cause the fuel trim to be maxed out (Vf=5V) as the ECU tries to add fuel to hit stoich.

I can't get it running at anything above those rpm. I touch the throttle and it bogs out and stalls. And if i don't touch the throttle it'll only run for about 10 secs. I also took compression readings tonight just to be safe. I've got
#1 - 132
#2 - 148
#3 - 142
#4 - 146
#5 - 157
#6 - 130

Is it ok that there is that much variation?
I also just ordered some ND 440cc injectors. They were only $50 for the set. They are used but supposedly low milage and in excellent condition. Figured i couldn't go wrong for that money.

 

[3p141592654]

Spec is 142 with no more than 14 psi variation. So you are out of spec, but not by much. Its definitely not your problem.

Sugar in the gas tank?

 

[Firechikin68]

Spec is 142 with no more than 14 psi variation. So you are out of spec, but not by much. Its definitely not your problem.

Sugar in the gas tank?

Doubt it. I heard sugar would crystalize into little rock like things. This was just a really thick goo.