Sooo like some of you know iv been talking about putting a TBI on the vette simply because it flows better overall then the crossfire. I know the TBI isn't the most effective platform but i choose it over the TPI because i HATE the TPI runners.
Atlest with a small cam i plan to be shifting at around 6000 with the TBI before running out of air. Found a intake for $20 and the throttlebody for $30.. polished up the runners a bit and me and Alex bolted it on.

I used the adjustable fuel pressure regulator from the crossfire and the injectors since i didnt know if the TBI came from a 305 or a 350

It runs about the same right now but its smoother. It only has a few degrees of timing when we took it out and the computer is still learning. Im happy though, heres some pics.

 

Did you not have to change the entire wiring harness/fuel pump out..?

 

i already had a TPI fuel pump in the car, The wiring harness was all plug and play except for the TPS, we simply cut a pig tail off a extra harness we have and rewired it.

Stock crossfire ECU is still running it too haha.

 

That's the cheapest swap I've heard of. The stock tbi intake is a marginal performer, I'd try to find a edelbrock or a holley at some point. I'm sure if you adjust the timing & fuel pressure alttle you'll be getting it to run real good. Good job!

 

yeah, budget builds ftw. I'll probably look for a nice intake for it and upgrade to the 454 Throttle body later down the road if i get some heads on the car.

Plan to go do some tuning later today see if i can't get it pulling harder.

 

how much for your crossfire parts ?

 

make me a offer. please consider the cost of shipping though because its going to be a heavy package.

 

Added some fuel pressure, set the timing too about 6 or 7 advance plugged the EST back in and went for a drive.

So much better, huge improvement over the crossfire the entire powerband is smoother and cleaner and pulls great.

Only problem is my tach is flipping out right now, won't stay steady.. might need to ground this odd resistor that the crossfire had.. not sure

 

Yeah, I kept that tach resistor too. Mine tach works good, I think its called a tach filter.
Is you tps adjustable? The 84s have a voltage spec, thats way they are slotted.

 

i don't think my TPS is adjustable, its alot like the modern ones you can find on the LT1s.

and cool, glad to know what that resistor does now.

 

The ecm likes to see the correct spec, that why I recomned using a 87-89 throttle body.

 

whats correct spec? i could check and see what its currently reading. It might have to do with the hesitation im having down low right now. Figured i need to keep driving her and let the ECU learn a bit more.

 

At closed throttle (idle) the tps spec is 0.545 volts, + or - 0.025v.
WOT should be close to 5.0 volts.
You might be able to slot your current tps holes alittle.

 

TPS is reading right in spec.. Still having that hesitation downlow, ima get a video later.

 

Try adding alittle more fuel pressure.

 

alright i know its a random question but can you help me, im still new to this site and i want to know how to post new threads on the messages boards

 

added more fuel pressure still doing it.. im having a high idle problem, once the car is all the way warmed up it idles at 1400 rpms. other then that and the slight hesitation down low untill i give it more throttle it runs perfect.

 

I think mine had a idling problem too, this is what I did, the ecm likes to see that it can close both iac valves, but you only have one hooked up, I found a iac & housing off of an 85 camaro 2.8L mpfi. I cut down the excess material on the housing. Now the ecm can fully operate both iacs even though only 1 is metering air.

 

go back to the main tbi page and click 'new thread'.

 

Vac leak. It should idle too low vs the CF. That is because the IAC command steps to open is 50% that of the 2 barell TB unit. Like 80 steps in CF and double that in your current TB.

If you witness that only fix besides swapping ECU's is to plug IAC port(extend pindle) and use throttle stop. You would lose fast idle on cold start.

 

was a vac leak, EGR blockoff was leaking.

 

if ur selling parts off the cfi icould use the throttle cable bracket.

 

reused the bracket for this setup

 

Still hesitation right off idle, No more vacuum leaks... About 13 1/2 fuel pressure.. Any ideas?

 

Its too bad you can adjust the tps on the high side of the specs. Remember the tps does what a carbs. acceration pump does. I guess i'd bump up the pressure alittle more.
Are you running an open element air cleaner? Is the outside air cold? Your ecm does not mearsure the air temp like some of the later tbi systems. The original crossfire had the thermac system to help fight cold weather hesitation.

 

its been chill air for Texas, I havn't put a air filter on it yet haha.

I wish i had a IAT..

 

I sounds like the TB and or the intake is cool and the fuel is condensing out of atomization as the VAC drops with opening throttle. Only fix for that is to throw more fuel at it(prom) or somehow add coolant to manifold or TBI. I think GM or aftermarket offers a plate to plumb some coolant to under TB unit(cold climate). RBob once posted photos for me to add coolant to manifold. I had no crossover in head. I would ask you to search for that post. The thread was started by me. The issue went away after I added more AE just off closed throttle to 20%TPS.

 

isnt there a newer ECU that plugs into the factory crossfire harness that uses a IAT and TBI?

 

See DCS site. they offer a HAM board that allow use of stock CF harness. It will need to be soldered in the ECU by you or a techncian. 1228746 allows IAT control. Others do as well. Many will use the later model PCM. 7427. I believe it was used on 1995 TBI trucks.

 

EBL live would be the same price as that HAM board, a burner, cable, chips and the ECU.. sooooo EBL or megasquirt it is..

Heres a video showing what the car does you can see how it hesitates between the throttle opening start of the video not so bad, middle its pretty bad..

http://www.youtube.com/watch?v=UgjbO-sz_nE

 

I'd start by getting some regular 350 tbi injectors, the cfi injectors are unique in the flow/pressure ratings (as far as front & back injectors, they have different part #s).

 

If he has a 82 or 84 vette he needs the ham board or splice in a connector(s) that will mate to the ECU. see dcs website for ham board info.

 

Having a TPS issue havnt checked the code for it yet though, and my stupid CTS is broken but my buddy took a video of me running through first.. Not the best of video and the cars not running optimal but figured id share..

http://www.youtube.com/watch?v=XfisT...el_video_title

 

Replace the cts & pigtail w/ the newer style. Much more reliable.

 

yeah i plan too

 

At least yours runs. I did this swap on mine and it has been a nightmare from day 1 haha. Nothing fit right so I kept having to mod crap. What are you running for an air cleaner?

 

what problems are you having? this was really easy.. maybe i can give you some pointers, Any open element air filter will work but honestly i have no money and can't afford to put one on there yet.

 

Well I had a 2101 manifold and I used that with an adapter and it kinda threw the placement of **** off so I had to mount the coil on the side like on a tpi car ( i also swapped to a small cap dist.) The manifold had a rib in between the two rear bolts so I had to notch the coil bracket. Then there was some other small problems because somebody hacked the car prior to me owning it. How did you reuse the stock detent cable(if auto)? Mine was way too short originally. The car runs fine etc but I keep having to change the way certain things mount so it isnt exactly "safe" to drive it as is.

 

I had a problem w/ the tv (detent?) cable, theres a bellhousing bolt that had a bracket or something on, it was holding down the cable. I reused my oem cable.
I used an open element air filter, at 2x14", flat type base.

 

What brand did you use? I got some sort of air cleaner here but the hood wont close with it and I don't wanna buy another that wont fit.

 

Its a K&N, the top part is maybe a 1/4" above the injectors. I didn't use a wing nut, I moded the hold down stud, I welded a a long nut to it, so I could use a screw to hold it down. I had to trim the filter enough to clear, then laid a thick bead of rtv & glued the filter to the lid. The filter was originally a 14X2 1/4" element.

 

I might not have to mod the filter because I am shorter overall with the 2101 than I woulda been with a stock type tbi manifold. I will have to check it out

 

So the car has been running fairly good since the TPS fixed and CTS fix.. How ever its starting to backfire on the occasion so I know the tune is adjusting but maybe a bit too lean.. What can I do??

 

Backfiring is mosy likely during AE/throttle movement. Enrichen the AE. I would do both TPS AE and MAP AE. Do incrementally 61 units at a time. If no response try 122.

 

I hope when I wrap mine up I don't have to tune it just to drive it :-(

 

I'd look into one of these carb/tbi hats, made by Spectre, they are 2" high from the flange to the top.

 

I looked at some of the carb hats but they are too much $ new. Maybe if I found a deal on a used one. Eventually I am gonna swap motors and go to mpfi so I dont wanna dump full retail money into this setup

 

Spectre 2.00 inch

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I am probably going to pick up the 1480 mr gasket air cleaner that the parts stores sell. its only 20 bucks and from what I keep hearing it should fit.

 

I have a summit chrome flat base and drop base assembly with a 2.00 inch KN filter available if anyone interested? One season on it.