prscarf

I would first like to thank everybody for being so supportive of a truck guy using your 3rd gen f body site. I have had several posts and You have helped me understand the workings of my truck considerably and looking forward to the future programming of my project. the wife and kids think I lost it but they have no idea how much fun this project has been so far.
I purchased all the eprom programming equipment and datamaster scan tool for the future installation of a 383 stroker for my 1991 4x4. I was going to use the stock tb from the oem 350sb (55lb injectors)but have now purchased a 454 throttle body complete (80lb injectors I think). The engine will be strictly used for towing and will probably reach wot on heavy towing applications. I purchased the 454tb unit because I was afraid of leaning out the stroker engine and figured it would be best to start this engine rich and try to tune the fuel table to reach 128 using the 454tb. Can I not compensate by dropping pressure on the regulator and changing the fuel tables get me to the proper afr or is this just to much injector for my application. I figured that I would have to purchase a new fuel pump for the 350tb anyways and if I got a 454tb I could save this money and also not have to purchase 68lb injectors for the 350tb.. what should I do on the fuel table reduce everything by a percentage? Also, will the 454tb sensors fit to the 350tb wire harness.

383 stroker, 64cc 23deg trickflow heads c/w edlebrock performer intake and adapter, cam is an extreme 4x4 comp. Cam. 12-235-2 grind ( .447/.462 lift, duration 210 218 lift @50, 111 lobe separation) . unit has hypr. Flattop floating pistons, eagle cast crank, 5.7eagle rods. 10.2:1 comp. Headers c/w 2.5” flowmaster exhaust. 1227747 ecm, asdu.bin.

FastBroker

PR,

I would initially "start" the 383 with the 350 injectors (55pph) at 11psi (stock) and the ASDU PROM you have in there now. I say this because it'll run ok enough to get you started cleanly and, when warmed up, BLM checking without washing the cylinder walls with excess gas, which could happen w/80pph injectors. You should then drive around a little and see how lean you are and then either make FP changes with the 55pph injectors (to continue) OR install the 454 TBI. Anyway, once you have the approx BLM's from the 55pph TBI, anyone here can give you a new Base Pulse Width (BPW in Tables on TunerCat) to put into the PROM to get you started up with the 454TBI OR advice on what presure to change to for the 55pph injectors. I can help, when you need it. I'm a truck guy myself, lately. Wrangler isn't really a truck, though, huh. Especially a 2wd conversion. I tow, too, though, so I'm with you on what you need out of an engine.

Are you using EGR? If not, you should eliminate it on a future PROM, too. But that's geting ahead of ourselves...

EDIT: I also have an ASDZ bin, which is a later BIN from the factory, if you want it. Changed something for operability, but it was a small change in open-loop vs temp table at low temp. can't remember. I started witht he ASDU, too, and it was fine.

[This message has been edited by FastBroker (edited April 10, 2001).]

Brent

iTrader: (1)

No need to start off with the 55lbs/hr units. To avoid the fuel wash that was mentioned, cut the BPW number back to 112-118, set EGR enable temp to 01 and run it. Then you tune idle fueling.

prscarf

I have no egr on the engine, if i forgot to mention it.

Brent

iTrader: (1)

You still should disable EGR in the EPROM. When EGR is enabled the ECM runs off a different BPW table and you will run too rich at part throttle like FB mentioned.

prscarf

FB, gave me some info on disabling the egr but i am a little confused as per where to change the bpw. i changed the bpw on the constant table only.