86 t type SPUDDERING at high rpm

[xsbc63x]

my friends got a 86 t type with the following mods
009 inj + matching chip, 3" downpipe, crossover pipe, built tranny, 24lbs on stock turbo alky inj, and a few other little things. hes having a spuddering problem at around 4500 rpm wot. fuel pressure at idle is about 38lbs, new tps properly adjusted, new coil, new plugs etc. i know these cars have lots of bugs if anyone could help me with this thatd be great thanks, dave
xsbc63x@aol.com

[Keller]

Originally Posted by xsbc63x

i know these cars have lots of bugs

No...They just have several delicate systems that work best when tuned to work together. When they're screwed up or mis-tuned, they don't play well together.

There is the potential for loads of fuel here, and not much air given the stock turbo. Running 24 PSI with the stock piece is a bit out of its sweet spot, so its heating the air a LOT. You may just have the motor swimming in fuel, or it may be something electrical. Without some scan tool data to see some MAF, O2, and other such data any guess would be nothing more than a crapshoot.

[xsbc63x]

ill get some scantool data in a little bit

[xsbc63x]

idle wot
maf 6 254
load 47 255
bat 13.6 13.2
integrator 128 128
blocklearn 118 128
air temp 72 66
tps .44 4.02
iac 60 110
cc 12-253 12-242
fuel psi 38 hose on 43 hose off
02 754 754
boost 19
alky on setting 5
no knock
int is at 128 which i think should be higher at WOT right?

[xsbc63x]

talked to jay from jays gn and he said to try a new coil module... tried it and same problem.

[Silverttype]

I agree with Scott, my personal opinion owning 4 TR in the last 16 years these cars will run with any new musclecar -- when properly tuned -- of course a little cheap combination of performance parts. In regard to your challenge...First when did the spuddering occur? Anything different that you changed on the engine, fuel--did it all of sudden start spuddering? I see the .02 volts are the same for idle and WOT?...you did not provide all RPM #'s when you were running 19lbs of Boost-- along with 02 volts, need a more "data screen" shots of your run, e.g., 2nd, 3rd and 4th shift points. This will allow better disection (hopefully). I would start with 15lbs of boost, increase 1-2 lbs at at time -- increasing fuel as necessary (CLOSELY monitoring your .02 volts, KNR, etc., until the spuddering occurs). You mentioned 24lbs even with alkey -- a lot with stock turbo setup and 93 Octane -- definitely getting the turbo extremely hot (Possible a fuel or octane challenge, dunno.) Thanks!

[Keller]

Originally Posted by xsbc63x

tps .44 4.02

Your TPS is very inadequate for WOT. It needs to be >4.50 at WOT. Usually needs some modifications to get there. Information on how to do it is on this site.

This still won't let you run sick amounts of boost with your combo.

You are also running borderline lean...but with your TPS, etc. its expected.

INT is usually locked at 128 at WOT.

[Turbo2nr]

Dave, exactly what chip is in the car? Race, or street? My car acted like this with too much fuel. I started with my biggest jet for the 7th shooter, and 29psi of boost to be safe. then lean it out. Funny, your 02s look good, but maybe 02 sensor is old, and tired.? They read leaner, and leaner as they go south. Car could actually be rich.?