TBI Mods.

[taz104]

Originally posted by addiction2bass
linkie no workie....

Fixed it...it workies now!

[addiction2bass]

o man i just remember...... i never replaced the fuel filter. i wonder if thats why i cannt spin the tires....... I GOTTA DO THAT ASAP

[4x4GMC1500]

Yeah I want to know about that vacuum advanced fp reg too. If anyone knows post up

[taz104]

I installed one on my truck.
Fixed my shifting problem. Used to shift rather hard, but now shift nice and easy. It was due to low fuel pressure added to the fact that my tranny needs rebuilt. 165k on my truck now...

Here's the information I gathered, so it might save you some legwork...
The GM part # is 17113186
You can get it here www.gmpartsdirect.com for $42 +SH...that's where I got mine. Shipping was pretty quick.

These guys did some testing (with a camaro, though) and found they needed a different spring...
If you call him, he'll explain what they found during their testing.

http://www.top-downsolutions.com/pro...70504069df8537

I used the spring that came with the VAFPR and it seems to work ok. I do notice a high idle when I first start it, but I don't usually let it sit at idle often. If I ever get some down time, I might order that spring and see if it makes a difference...

[Farkum]

With my new engine I got a 454 TBI setup so I thought I would put it on. The engine runs awesome with the 350 TBI but when I throw the 454 on it starts to lean out too much when I give it throttle then it back fires. I pulled the 350 chip and tried a couple differnt spares I had and I got it to run pretty good with a 4.6 chip but it isnt perfect (no backfiring but throttle response isnt right yet). Does anyone know what I can do to fix this problem?

[CKTA]

*update*

BTW guys, check out the new issue of Chevy High performance. They install a Turbo City t/b along w/ other TBI mods on a Vortec headed 305 and get almost 300 rwhp.

[addiction2bass]

so i gotta buy that and the spring?



id like to give my truck some more pep for under 100bucks......

[taz104]

Originally posted by Farkum
With my new engine I got a 454 TBI setup so I thought I would put it on. The engine runs awesome with the 350 TBI but when I throw the 454 on it starts to lean out too much when I give it throttle then it back fires. I pulled the 350 chip and tried a couple differnt spares I had and I got it to run pretty good with a 4.6 chip but it isnt perfect (no backfiring but throttle response isnt right yet). Does anyone know what I can do to fix this problem?

I'm not sure, but just by your explanation...you are running a 350 chip which, I'm sure, is calibrated for a 350 tbi.

Is it a custom burn for your motor or just for the 350? It wouldn't take into effect the extra fuel you're dumping into the intake by using the 454 tbi....thus flooding slightly and your late detonation (backfire)
I would guess that mod requires a custom chip burnt.

Originally posted by addiction2bass
so i gotta buy that and the spring? id like to give my truck some more pep for under 100bucks......

Do you already have a tbi spacer? For under $100, that would be your best mod.
Plus checkout the free mods in the Tech Articles section.

[Beaver Customs]

I thought the concensus was still pretty much on the fence about TBI spacers and their effectivness.

[taz104]

Originally posted by TBI_Believer
I thought the concensus was still pretty much on the fence about TBI spacers and their effectivness.

I think mine is pretty darn effective. Took mine off for a couple weeks.

My gas mileage decreased (HUGE consideration here in Cali) and the throttle responsiveness wasn't the same. I'll be on the side of the fence that is Pro-spacer!

[addiction2bass]

ya ive thought about those but ive heard quite the differences about them

[Farkum]

I am pretty sure it is running it lean because the 454 has a lot more air flow and the 350 chip isnt compensating for that by telling the injectors to dump in more fuel. However when I throw the 4.6L chip in there then it runs a lot better so yeah I am thinking I need a custom chip burnt too but who can do that for me. Is there anyone on the forum within a couple hundred miles of MN that could help me with that?

[Beaver Customs]

Talk to Brian @ sales@tbichips.com If the only mods you have done is the larger TBI unit they should be able to burn you a chip without any specific info. Worse comes to worse they will talk you through d/ling the info through WinALDL.
Brendan

[addiction2bass]

with the spacer do i need the T6 gas line extension fittings make installing the spacer a snap. $12.95
T7 injector spacer add another 4 horsepower. $10.95

http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW


or is thier a cheaper place to buy the complete kit?

[taz104]

Originally posted by addiction2bass
with the spacer do i need the T6 gas line extension fittings make installing the spacer a snap. $12.95
T7 injector spacer add another 4 horsepower. $10.95

or is thier a cheaper place to buy the complete kit?

BE WARY of buying your spacer on Ebay. I have read a couple of posts on the forum where people got scammed and their spacer didn't fit right....

As far as the lines, I didn't use them, but it also was a pain in the azz to connect the lines to the throttle body, so they might be worth the $$$.

I have no experience with the injector spacer, so I can't help you there....

Good luck!

[oldred95]

I ordered the ebay TB spacer and the injector pod spacer. I haven't got it yet but it should be here either this week or early next week. I'm puttin a fuel pressure gauge in line so I can get all the extra length I need for the pressure line right there. The return line might require some persuasion but I'm sure it can be done. I'll let you know when I get it bolted on.

[addiction2bass]

so should i just go ahead and buy the airraid one?

http://www.stylinconcepts.com/part.c...&CategoryID=28


you think that spiral stuff would work beter than the one on ebay?

its either the spacer or a shift kit.
buy for the shift kit i dont know what kinda trany i got.

[oldred95]

I was told the straight threw design without the spiral deal was better. Read this thread and it should answer your questions.

You have a 4L60E automatic transmission.

[Farkum]

Yeah the spiral design is really bad for torque. It decreases air velocity and you wont notice a differnce in HP but you will definately like the straight through design better for torque.

[Greenbuggy]

I'll clarify for Farkum since I did the system...what he has in his truck now is the setup I had in my '72 up until I bought an '83 K5 with a 6.2 and parted the '72 C10. I built my own harness from pieces from an '89 1-ton truck wiring harness and an '89 burb harness since both had seen better days (and both were hacked up and needed to be modified anyways to be put in an older body style truck).

Useful information:
www.chevythunder.com
www.diy-efi.org
www.gmecm.com

Setup as currently resides in cort (farkum's) truck:
454 TBI unit retrofitted with standard 350 injectors (orange tops)
2bbl TBI --> 4-bbl Qjet adapter, coolant bores and vacuum ports plugged (on adapter)
Standard MAP, TPS sensors still attached
Edelbrock Performer Q-jet intake
Chips from '93 Chevy C1500, 4.3L, 700r4

While in the '72 I had a full barrage of sensors like the truck the setup was originally in had, everything except for a VSS (which I would have put in had I intended to keep the truck longer). The 350 chips in combination with the 350 injectors and larger 454 throttle bores meant that it would flow a mismatched amount of fuel for the amount of air flowing through, and accordingly would run lean and backfire under hard acceleration. Digging through spare chips for the TBI setup I found a set of 4.3L chips and tried those, and all I can think, for whatever reason, is that the 4.3L is programmed for a higher acceleration fuel enrichment value because it didn't backfire. As in my truck, Corts truck has slight but present hesitation but will definitely light up the tires with the pedal to the floor after the hesitation. I think it needs fine tuning. My recommendation for anyone who would do this swap is to go for it, I noticed about a 2.5 MPG increase over the quadrajet and much, much faster starts. Unfortunately the '72 had rust damage beyond my capabilities for repair and I decided to part it out. I think that cort as well as anyone who doesn't already have the capabilities to do so should check out the xtronics pocket romulator, a sort of "chip emulator" that allows for adjustment on the fly to GM, Honda and Nissan autos and trucks.