I am fairly new to this tuning thing. here is what i have

1991 Ford Ranger
2.3 Turbo Charged (1985 Turbo Coupe engine)
Holset Hy 35 with tubular header
Msd 6al With two-step
Ported intakes
NPR Intercooler
75lb injectors
Walbro 255
Adjustable Fuel regulator
SDS EM-4 with Wideband
Stock head and shortblock

I am having to richen the motor up on start up ( with the lean/rich controller) (Around 27 on the rich side then back it down to 19-22 depending on the temps) quite a bit to get the idle in the 14.6 range.
What could for easier starts?

When i decell the engine drops into the mid to low 10's with foot off the throttle. Where would i start to add fuel to smooth that out some?

The AFR's are pretty good under boost all the way up to 20psi. I need to change my plug gap from .32 down to about .24-.25 because i am blowing out spark at anything over 20psi. But if anyone could comment or reply to this would be really helpful.

Thanks,
Josh

Before you tune the engine temp and start cycle parameters, I would make sure that the RPM fuel and MAP fuel settings are dead on while the engine is at operating temps. After you tune the engine properly, then one time that the engine is cold, turn it on, let the oil pressure rise, and try to drive off. Have some one look at the temps where it feels like its stumbling and add fuel at those temps, around 140-150 *F you should not need any enrichment.

On deceleration, if your hitting 10's in the AFR that means that your high vacuum (MAP) settings are to rich or to high of a value. On racing turbo applications it is desired to run a lil rich on high vacuum values to help with keeping the turbo spooling when you shift. But too rich is just wasting fuel. Lean out the high vac values until you have reached your desired AFR on decel, or you can just cut fuel on decell at high vac settings, but turbo spool after shift will suffer some.

What is your fuel pressure set at idle? Also, do you have a rising rate FPR? and what is the ratio of rise if you do have one?

What heat range spark plugs and spark plug wires are you using?

Whats your AFR at 20 psi?

I am running a home made adjustable fuel pressure regulator. Raises 1:1 (boost:fuel)

I am running autolite 764's gapped @.32

Update: I melted a plug wire and had to limp the truck home in a downpour on 3 cylinders. I popped a head gasket in the process. I will be putting it back together tonight and starting over. Will keep you guy's updated and thanks for your input.

Later,
Josh

you better check the head for being flat and not warped from end to end. 20 lbs is alot of pressure. you should be using head studs instead of head bolts. do you have a blow off valve ? this relives the built up pressure from the turbo when the throttle is closed. this will help ensure the charger will not be damaged on decelleration. inspect the cylinder walls for damage too. this could be information on how well it is holding up. when tuning the engine to get it to run properly you should adjust the waste gate down to almost no boost until you get it running properly, then you increase the boost along with your fuel, rember the lower the number on the afr the richer it is and the higher the number the leaner it is. good luck

Dave,

I have a blow off valve.
I have a external wastegate that all i can turn it down to is 11.7 psi.

I just cleaned the head and block with a razor and a scotch brite pad. Then brake clean and a air hose. It is running fine right now and i even reused the stock head bolts..

I am not to worried about this engine if it goes.
It is all stock junk yard longblock. I have a built shortblock and a heavy ported and polished big valve head with a lumpy camshaft. Ready for install..

Now back to the tuning. I have been playing with this system and reading alot here lately about sample maps and the sds manual. I need to sit down and fix my high idle issue and then start tuning because it is hard to tune from 1500 to 2000 rpm.

I got a copy of a tune from a guy in South Carolina his setup was pretty much the same as mine. It ran fine all summer and then when it started getting colder it would spit and sputter and the AFR where all over the place so i am trying to start all over again. I copied down all of my data first though.

Later,
Josh

Ditto on what Felix says.

-Barry, SDS.