Going to be installing a Holley 502-6 tbi unit. I'm going to bore out by edelbrock tbi intake to 2" and use a 1" spacer. Hopefully this will give me some good airflow as well as more fuel volume. I believe the holley unit uses 65lb injectors, I'm going to install a walbro 255lph h.p. pump, should I keep the pressure at 11psi as recommended or can I bump it a bit? Also, the instructions mention adjusting the tps voltage, how can I do this?

THanks

 

Please listen when I say don't even bother with this swap unless you plan on doing your own tuning. You're going to be changing some very key parts that will drastically change the way your motor runs. Without tuning it's going to be a big sloppy mess. If you're lucky you'll get it to run as good as it was stock.

I would look at exhaust work first, then maybe the intake side.

 

What other mods do you have at present?

 

I'm currently running a relatively stock l03, i've removed AC and SMOG, open element(waiting for cowl hood), edelbrock tbi intake, diverter valve removal. I've got a Jet stage II chip installed also(from a few years back). Haven't done anything internally only because I'm building a 383 stroker. I just figured that whatever mods I made now I could move over to the 383. I don't want to invest in cam or heads because they'll go on the new motor but i'd like to stay with the tbi unit. I'm waiting for my tuning equip to come from Moates, the burn1 is on b/o. For years the car has been a show car, I compete with my car audio, a complete Rockford Fosgate system from head to toe. But now I want to move to the engine side. It's already chromed and polished(for show) so I'm moving on to the power.

Thanks.

 

In that case I would do the exhaust and get the gains from that. Everything you do to increase air through the engine has to go through the exhaust. Stock on these cars downright sux. At the stage you are at it would help more than the larger TBI unit or larger injectors.

HTH

 

I'm going to be doing the exhaust soon. I've got a set of hedman headers 1-5/8-3" collectors, shorties and going to have single 3" ss. I think the 3" should be fine even with the future 383. BMMonteSS, I should be getting my tuning hardware shortly from moates (burn1 on b/o), can you make any recommendations to programmign the prom to accomodate the larger tbi or is it not that simple?

Thanks.

 

The big thing is getting your injector constant (BPC) set correctly and then working on your pump shot settings. If your BPC isn't set correctly your whole tune will be off. The big throttle bores introduce so much more air quicker that you need a good bit more fuel when you first crack open the throttle to compensate. At WOT it won't make that big of a difference because you won't be flowing any more air than you are now. Check out the "come in for a free tune" sticky for a perfect example of what needs tuned for a big throttle body. XJ just had a 350 with a big TB and exhaust and needed some pretty big fueling changes to get it drivable again.

 

Remembering the past here but is no one having any problems with the Holley injectors? IIRC they used to be problematic

 

DM91RS
Nope no problems with the newer (last 4-5 years or so) Holleys they changed / fixed the Holley injectors problems.

 

If I'm not mistaken the problematic injectors were the ones with the black domed caps on the injectors. They seemed to flake out as soon as you put any pressure to them.

 

Thanks for the replies guys. You input is greatly appreciated.

 

Bummer on the black cap Holley's as that is what I have sitting. I had a GM injector pod on there already anyway. I want some 90 pounders if they really exist after reading some of the posts lately.

 

They exist, just not from holley

 

If you make friends with someone across the Mexican border you can get 125 lb/hr injectors from I6 TBI engines that will fit in the HD truck injector pods, which will fit our TBI units.

 

We really need to find a source for these injectors.

 

and I did not mean Holley injectors. GM only
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What are the HD pods you speak of?