North American Turbocoupe Organization

I'm new to the board but have been poking around for awhile, doing research. I've got a 100% stock 85 TC that is having a problem under boost. When it gets to about 10 PSI it begins to sputter and will not pull until I back off and let the boost drop. I have replaced the FPR, the fuel filter and EGR, It is a 5 speed car. I haven't pulled any codes yet. I have tried disconnecting the various sensors to see if they were bad but no noticible difference. The exhaust is not clogged, thought it was but it isn't.

I suspect it is a fuel delivery problem, but with the stock injectors do you think the fuel pump would be running out of fuel or fuel pressure under boost?

I will try to check the idle fuel pressure in the morning.

Also, would going to a carb with a hat be worth the effort? I can get all the parts I need pretty reasonable to do the swap if it will help with this problem or would it be more of a pain to tune than what it is worth?

thanks
Gordon

Hello and welcome.

I would recommend you run the complete fuel system diagnostics including at boost since that is where the problem is. Fuel pressure at idle does not tell you what fuel pressure under boost is. It is thouht that the stock fuel pump may lose capacity with age.

Pulling the codes is always a good idea. Also how old is the tuneup and what brand(s) of parts do you have in it. old or weak parts may succum to the additional stress of boost.

http://www.turbotbird.com/techinfo/Fuel_...ostics.htm
http://natomessageboard.com/cgi-bin/ulti...0;t=000004

Tune up less than 500 miles ago using Motorcraft parts or parts recommended from this as well as other turbo sights. I believe I will try and after market FPR made by kirban as soon as I find the sight again.

I will eventually need a better one anyways because I plan on boosting it up a bit over time.

Thanks
Gordon

http://www.jdsperformance.com/index.asp?...e=all&pg=4
86 to 93 Mustangs - KIR5005.

Thanks

Gordon

How much gap did you put on the plugs? Too much and you will get missfires under boost.

I started with 32 but backed it down to 26 without any change.

BTW, I live abour 20 minutes east of Knoxville Crawdaddy.

Gordon

Quote:I started with 32 but backed it down to 26 without any change.

You shouldn't have any problems at 0.032" with a basically stock set up, even if you turn up the boost some.

An AFPR like the Kirban isnt going to help you now if the fuel pump cant keep up at current boost levels. A fuel pressure test under boost will rule in or rule out a weak pump, plugged filter, etc.

I will come take a look at the car if you would like. My name is James Crawford.

Email: [email protected]
or call me 423-494-0098