94 Z71 TBI on vortec build runs richer than a crooked politician!

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Originally Posted by woody80z28

I bought injector bungs on ebay for $30 and a fuel rail for $80 and I'm gonna use the TBI TB (with no injectors) and drill and weld the bungs in my Vortec Performer carb manifold. I have a steel carb to TBI adapter plate that I'm gonna weld the fuel rail mounts to and it should all be pretty low buck.

Here it was on the initial TBI build in 2011.
https://i.imgur.com/flI39Yk.jpg

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I thought about this as well, I have a vortec throttle body and could do the jumper in my factory ecm to go multiport. Let me know how hard it is to weld those bungs in straight and how your controlling it, I may go that route. I figured out after seeing my rpm air gap intake covered in condensation that the wet intake is causing a lot of my problems in cooler weather. I have a heat riser tube on the way to help but im going to need to go multi port somehow to get it rite! nice looking build by the way!!

looking at this picture above. how are you going to weld bungs so the injectors sit at the same height with the different levels the roof of the intake runners sit with a dual plane?

The bungs are longer than they need to be. So I am going to drill the manifold all the way through on the mill at work. Then I'll set all the bungs at the same depth and cut them off flush with the bottom side of the intake.

Hey Jimmie, I’ve been having the same symptoms that you are having. My timing was all over the place, it would stall, idled bad and would fall on it’s face. I changed everything I could think of, changed the tune, checked valves and was about to go crazy. But every once in a while it would run good so I moved the coil from behind the TBI and away from the distributor. Now everything is normal and it runs better than it ever has.

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Originally Posted by dhworkin

Hey Jimmie, I’ve been having the same symptoms that you are having. My timing was all over the place, it would stall, idled bad and would fall on it’s face. I changed everything I could think of, changed the tune, checked valves and was about to go crazy. But every once in a while it would run good so I moved the coil from behind the TBI and away from the distributor. Now everything is normal and it runs better than it ever has.

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I'm willing to try anything at this point, thanks for the input. I'll let ya'll know how it goes.

This thing is getting the fuel to it, 10mpg worth of fuel and my AEM WB reads almost steady at 14.7 with throttle in one spot at cruise on flat road but the second you gas it she drops to 16+ then picks up if I downshift to get the rpm's up. It act's like it's just getting raw fuel and not mixing in the intake. It's new stock AC Delco injectors for 5.7 and fuel pressures at steady 13lbs, tried 18lb spring but it gave 20 actual lbs and flooded out at idle. I think I see why the stock TBI intake was water heated and I'm thinking the air gap intake I'm using is part of my issue, read a couple others having issues with the same setup I currently have, some had better luck with the factory air cleaner and heat riser from exhaust manifold but after reinstalling mine there was no noticeable change. On cool days the intake has condensation forming on the outside, just seems to make more sense to have 8 smaller injectors with higher pressure spraying with better atomization than the TBI low pressure spurt spurt pattern.

OK so after looking at the ugly spray pattern on my injectors for awhile just playing around with it I did some more tinkering around and found the wires and connectors to my injectors looked not so great, tiny little cracks in insulation and inside the connectors were off colored so I cut them off and checked them and the resistance was high. After replacing them with new ones I immediately noticed my spray pattern was better and I could see the massive AE pump shot every time I moved the throttle now! Also before at WOT my AF gauge was at 13.4 or above, now the first test drive AF at WOT fattens up to 10.2! Now I guess it's time to start the tune over again and see what happens. I still plan on some type of MPI later on this summer, possibly some sort of Frankenstein with MPI spider injection crossed with air gap intake :homer: but I haven't looked that idea over very good yet?

Hey Jimmie, was wondering how it’s going since you changed the injector connectors. I’ve ordered connectors and hope that is my issue since I’ve adjusted my VE table to the point where it should be lean and it’s not.