Tuning Questions

[85zoom]

Gang, what's your opinion ? My 85 T has an ATR fuel pump (previous owner installed, but I haven't verified it with my own eyes), Kirban AFPR, cone air filter, an unknown chip labeled 84-85 GN custom, and a Hi-Perf CAT. To get the car to really run good, static FP is lower than recommended, around 30 lbs. There is no knock, car pulls hard, etc. It runs pretty close to a HotAir dream ! What worries me is the low FP setting readings. If I turn it up to 36 lbs or higher, I get slight knock, but a definate stumbling/hold back kinda performance. My parking stall has 2 black spots where the exhaust pipes are: too rich ? So, opinions ? Inaccurate FP guage (permanent mount on fuel rail) ? FP maxing out at higher pressure settings ? Unknown chip parameters ? Injectors ? As soon as I get the chance, will measure O2 volts. Can anyone verify that hooking up my Fluke DVM to the O2 line to read volts is OK ? Or will it load it down and give false readings ? I know this is a blind shot, but I am curious of other theories so I can broaden my troubleshooting thinking. Thanks, gang!

 

[TURBOV6]

What's up Gman.....

Well the fp seems way too low, I assume its a bad fp guage. I have good luck with 42lbs of fuel (line off) on my "T" and with the Kenne-bell chip 43lbs fuel. I use A/C delco CR43TS plugs and gapp it at .35. My "T" does blow black smoke at the tail pipes but with the fuel pressure low or high does not help, a friend said just black crud/condensation build up because its old. What boost is it at? Anything above 12lbs will knock on my car, so i'm using the stock chip in now.

 

[85zoom]

I'm running about 17 lbs boost. And the gauge is new from Kirban's, too. And if I didn't mention earlier, my car is non-intercooled. Still stumped..................?

 

[TURBOV6]

My T-Type is also non-intercooled

17lbs is too much for pump gas. Try to borrow another guage and see if the fp is different.

 

[Turtle TR]

17psi isnt too much . I hit 20psi with the ported elbow and I had to lengthen the rod to have the wastegate reach the puck arm . Now my car's broke.

 

[Geoff87]

Convert to a '87 ECM, so that you can use a scanmaster.

Greg (GNZero) used to own your car (I think). Shoot him an e-mail if you have any questions regarding mods done to your car.

 

[TURBOV6]

Originally posted by Turtle TR
Now my car's broke.

I wonder why

 

[85zoom]

At 17 psi, I don't feel any knock. I know just because you can't feel it by the seat of your pants doesn't mean there isn't ANY knock. I'm sure there could be a few degrees of knock, but the car runs really good. As soon as I turn back up the FP, I get the poor performance again. And, yes, I did buy the car from Greg. I keep in contact with him when ever I can. I guess O2 readings are in order to see if I'm running too lean. Here's something to throw in the mix: 1) is there a difference between running a 1/4 inch I.D. fuel hose or using the stock metal tubing (1/8" I.D.) to route vac/press from manifold to FPR ? 2)The fuel gauge from Kirban threaded onto the shrader valve on the fuel rail, but due to the design (?), it didn't extend down enough to push the pin in to open the flow, so I just removed the valve pin and mounted the fuel gauge permanently on the rail. Could any of this alter readings ? Thanks for all the great responses so far.

 

[85zoom]

Originally posted by TurboV6
I wonder why

Chris, you realize YOU opened the door on this one ?! LOL

I guess the question is not "how much boost ?" but how long the duration. Kinda like cooking a ham, 350 deg for 3 hours, or 6000 deg for 3 seconds................Sorry, just couldn't resist. OK, back to topic.