Just recently got an 83 DT500 Transam, Its running like ****, and I've heard many bad things about the CFI system... as well as it being one of the weaker motors... is it possible to pair a TPI with an LU5? and if so what would i have to do? Plus it HAS to smog i live in CA. If not what are some mods i can do to get some good HP out of the CFI without missing my rent payment!?
thank you!
-Ino

 

Honestly, The easiest thing might be to go tbi. Find a harness in classifieds and I can program a prom to work if you need. The only reason I say tbi is it would save you from putting in a fuel pump for now? Assuming you have good fuel pressure. Do you know what the laws are for injection conversion, does it just have to have all the emissions for the cars year there and functioning ?

 

I believe it just has to pass emissions for the year and the motor has to meet specs for the corresponding year, There are a couple smog shops in my area that will look past complete year specs as long as the motor was offered in that vehicle platform. I'm pretty certain it just has to have all the regulatory emissions standards for the cars year in proper running order.

May take you up on that programming!

 

If you do go tbi, you might be able to get one from a truck for pretty inexpensive. The center bolt holes of the intake need to be elongated to line up. The harness and ecm I would look for a 89-92 tbi Lo3. The 89 caprice used a L05 so the prom programing will work
From that platform.The ecm service number is 1227746. The 88 tbi f-body was a one year only ecm I would shy away from that. IIRC your LU5 is a 5.7 .
It all comes down to your budget on the conversion Tpi will cost more to do.

 

Ill look around some junkyards then, there are quite a few up here I'm sure i could find one, i have a the TPI runners and plenum already from a friends old camaro, I would have to find a harness and the rest of the TPI system though. LU5 is a 305 (5.0) and as far as budget, i am a college student! haha 'nuff said. there are tons of junkyards around here though so I've learned to be a junkyard viking so anything i could interchange from other cars would be immensely helpful. unfortunately these CFI motors were only rated at 175hp i would like to try to get a little more out of it, i will probably go the suspension route first as i have with my previous birds, but i still would like to have a little more kick than what is stock for the car.

 

I would lean towards tpi , But You should have a budget first to complete it. A few ways to cut corners doing tpi. but reliability over crapfire I. Would atleast go tbi. Would be fun if you were closer to work with the 1227749 ecm to operate the crossfire. I'm sure if one could get that going well it would run amazing and would be more reliable. just a not any 89-92 tbi from the f-body has vats so that will have to be reprogramed out of the prom so the injectors can fire.
just to save your self a headache budget injector cleaning or new injectors for your project.

 

Alright ill start putting a budget together, i hate to ask but what are ways to cut corners with a motor? and with a TPI would i have to change the heads? Ill try the cleaning route first before i buy new injectors because those can get pricey. Ive read a few good ways to get them pretty pristine. Closer? are you in california? and would it be worth it for me to grab an dcm out of a TPI car as well? Should i grab the dash harness and engine harness or will my 83 Dash harness accompany a TPI harness?

 

I'm in Colorado , You will not need to swap out the heads. If the only thing your missing is the to intake send me a pm.
for a 305, you would need these
http://www.southbayfuelinjectors.com...ebird-305-tpi/
I would go with speed density , there is a harness and ecm in the classifieds for sale
https://www.thirdgen.org/forums/engi...rness-ecm.html
It has the wrong memcal and vats , but We could work a trade if you wanted to go that route.
You would still need a acdelco ep241 fuel pump
Throttle body ?
Fuel rail ?
Crossover fuel lines
Misc sensors.
the expensive part of the swap is the injectors, harness and ecm and memcal.
I have some ecm and memcals and can do reprograming to help save you money. but I think the conversion will end up being $5-650 when your done.

The dash is totally separate You don't need to even deal with dash wiring. Except getting power to the second injector bank wiring. Not a biggie.

 

That is an awesome price for the injectors! much less than what i had anticipated! i have the throttle body, and a fuel pump (i bought for my 91 when a while ago, ended up being a fuel filter) but the rest i should pick up! ill send him a message in the AM about the ECM and Harness! thank you for the advice btw! If i don't end up getting his ECM let me know what you'll get rid or your memcal and ECM for.

what would i do about the power issue to the 2nd injector bank?

 

I'm not sure what your fuse box looks like, but I'm sure there is a extra spot for a acessory power. IIRC the injectors use a 10 amp fuse. You could allways tie both injector bank wires together . That has been done for tbi to tpi harness conversion and works fine.

 

On CFI, each throttle body has a dedicated power supply from the fusebox. Perfect for a TPI conversion.

 

Learned something new

 

If ist is for the TPI look then obviously go TPI, if it is more budget and performance related go TBI.

 

If youre in Ca just fix the CFI youre going to a whole lotta trouble for practially nothing.

Better check with your smog ref first if you follow through to make damn sure you do it so they are satisfied. Dont rely on web info 100%

 

^^^^^
What he said!

 

What are the Pro's and cons between TPI and TBI?
I thought the TPI was more performance and efficiency related... i thought TPI was the better route to go..

 

I was curious, so I gogled Crossfire just to learn a little more. Came across this link that has some great troubleshooting info, as well as performance info.\

http://www.corvetteactioncenter.com/...oceedures.html

Since CA is such a stickler for keeping things stock, maybe a little work on the crossfire is not a bad idea, before you jump into TPI and get caught in the SMOG ringer. Just a thought

 

Definetly don't want to get caught up with the smog thing, fortunately i just have to get it to pass this one time, in the county i live i only have to smog at transfer of ownership, unfortunately if i move its a different story though... I got it to stay running for a bit, idle is really bad and it back fires and sounds like it has an exhaust leak... i replaced a few vacuums lines and soaked the throttle bodies and sprayed carb cleaner through the intake, put in some 91 with an octane booster and some injector cleaner, it didn't fire right up but eventually i got it to run... it threw a code for the TPS (used a paper clip as a jumper wire at the diagnostic plug) that would explain some of the really rough idling, i would actually like to keep the CFI though, i just have to figure out a way to get some decent power out of it... or possibly fade the CFI in for a TPI or TBI, if i do that i will have to figure out a way to keep an address here, You guys are definitely right with smog logistics so hopefully theres a good way to make some good power out of these, trust me i will be beyond pissed if i get smoked by a civic especially since it says PACECAR across the entire door! (I'm sure any of you would be to!!hahah) :P

 

Take a look at the manifold and you will know why you can't get performance from one of those.
Half the port is blocked at the head.

http://www.ebay.com/itm/CORVETTE-CRO...-/331085284797

 

Any updates?

 

I was going to convert an 84 Corvette CFI over to an 89, TPI system for a friend. I came up with a spread sheet for the 89 ECM harness and what wires would be used from the 84 harness made to work with the TPI system. The 89 f-bird harness won't work in a 'vette but we could have used the connectors and spliced them in.


I attached that file to this post if you are interested

 

The Crossfire system is great. It's only had bad reviews because of the control system, and the placement of one of the relays (in the Corvette), and so that meant all Crossfire systems were inherently "bad".

I've installed a Crossfire system on my Grandfather's '71 Chev pick up with a 305 (currently, it had and will again have a Vortec 5.7, once I get done rebuilding it.) It runs great. I used a late model TBI computer from a '95 Chev Pick up, since I also installed a 4L60E behind the engine.

I would go through the tune up procedure before doing anything else and make sure everything is in proper spec, TPS adjustment, coolant temp sensor, etc, etc. Any system will perform poorly if the ECM is not getting the proper signals and/or the actuators are not performing up to par.

If it was my car, I'd also swap to a late model TBI ECM to have some fun tuning it, but that's not a necessary step.

 

nice

There are many ways to improve a CFI system one is ebl flash 2 is a 85 corvette fuel pump and adjust the fuel pressure at the drivers side TBI regulator to around 13-15 psi.

 

i remember an episode of Shadetree Mechanics (or maybe Two Guys Garage) converting a Crossfire to TPI on a Corvette, looked really easy too

 

I remember that episode too. It was two guys garage. Its more complex then they showed on tv . You still need to change the fuel pump to the tpi version. Which Is a common CFI mod.

 

How can you get performance from a manifold with half the port blocked?