I have an '88 350 TBI truck that I would like to go Multiport with, but keep the stock TBI unit as a throttle body minus the injectors. I know that Edelbrock makes a kit to do this, but it does not work for the '88 model year ecm. Besides I think it's over priced.

Is it possible to take a carb/tbi manifold and have it drilled for 8 injectors and a fuel rail? I thought I've seen it done, before. I have also thought that the TBI ecm would probably need to be dropped and I could use a TPI or aftermarket computer spliced into my stock wiring.

It seems to me the only real expenses would be a chevy fuel rail/injectors, a TPI ecm and chip for a 350, and the cost of machining the holes in my intake, plus a fuel pump. I figure it would run ok on a stock TPI chip, but I know it would need to be tuned at some point.

Is this possbile?

 

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I am considering something similar in future. maybe next year/season. not sure how successful you would be converting a standard manifold by welding bungs. seems i read it is difficult to get it right and flow correct. i would lean toward a victor jr efi or a prof prod unit. I have a 7.4L TBI that might be my TB for port injection but I really want a 4 barrel.

stock harness compatible with a TPI ECU? check Painless Products for an adapter. I use Hammed EBL which will fire port injectors and is compatible with my TBI harness. Seems I am close.

 

If the price of the manifold is too high, I think I would rather just go with a stock TPI or stay with a TBI based setup.

I don't think my harness is compatable with TPI, I know I would have to rewire the connector for the TPI plug. I already have a TPI computer laying around in my junk, I'm just not really sure if it works.

Is the EBL with the port mod compatable with a TBI harness?? I've been looking over those products for the past week. I wasn't sure what the "port mod" really is? Is that a TBI comptuer that can run a TPI setup or a flashable TPI comptuer? Can I get one to fit my '88 truck harness with no issues?

 

TRUST me when I say this. It can be done I've done it and it makes REAL GOOD POWER. I did it with a stock tbi harness (non spliced) EBL controls, 51 mm tbi and everything you need with the smog stuff hooked up. Car has killed modded LS1s, LS2s, muddstains, vettes and chargers. They didn't think that setup could make the power it's making.

 

Alot of guys are doing this on the megasquirt forums. They seem pretty happy.

 

Yes you can. We did it with a gm computer and the factory wiring harness that was already in the car which saved a boat load of money. The car looks so stock you couldn't tell it was modded (until you ran him)

 

How did you get the injectors into the manifold? And what manifold?

 

I used the edelbrock muti-point conversion manifold that is already set up for the injectors. You can also use the holley manifold that comes with the efi kit. Or have a speed shop fab up one on you own manifold. We have one that we got from summit for his stage 2 set up. It comes set up for 8 inj and you can buy the matching fuel rails too. We went this way because the tune port swap would have been a nightmare and to upgrade for more power would have cost too much plus the harness swap. If you want I can post some pic of both manifolds.

 

So you paid the $1000 for the manifold? Or is there a cheaper part number? This sounds great. Exactly what I want, how much did the swap caost total?

 

His car has went through many stages (cause he didn't know what he wanted to do at first) so to give you a true total amount would be kinda hard to do. Everthing you see in the summit/jegs catalog as a kit can be ordered sep. And don't bother with a tpi ecm, just get the ebl and you'll be happier in the long run.
Right now he has the Edelbrock tbi conver manifold on. Future plans are to use the holley manifold and accel 1350cfm TB on a bigger motor which he already has. But I can tell you what you're going to need to make 375-400hp+ to the rear wheels with the tbi conver set up.

 

QUOTE: Is the EBL with the port mod compatable with a TBI harness?? I've been looking over those products for the past week. I wasn't sure what the "port mod" really is?

yes. check out dynamicefi.com. For me 1984 Vette. No. I needed to have my 8746 -EBL computer modified to match up to stock Vette harness. Called HAM done by speedtronics.net

QUOTE: Is that a TBI comptuer that can run a TPI setup or a flashable TPI comptuer? Can I get one to fit my '88 truck harness with no issues?

Mine is a 8746 computer that is no longer considered as such. Now it is EBL computer. Just looks like a GM unit. Flashable. yes with that option. I will say no longer a TBI nor a TPI unit. EBL unit. Can be ordered TBI or TPI-Port Inj. Again see EBL site for more info on that "option".

 

That's the way to go. Little cost easy hook up and lots of tunning options.