I was wondering if the stock fuel lines on my carbed 84 would support the 15 or so PSI needed to run a TBI set up? I know if I went TBI, I would have to get a new manifold, TBI unit and fuel pump along with all the wiring but the fuel lines, so far as I've been able to find, aren't ever talked about other than going with high pressure TPI setupts. thanks!

 

I'm pretty sure you would need to plumb a return line. On a carbed car, there is only one fuel line, but on TBI/TPI cars, there is a fuel feed line, and a fuel return line.

 

I actually have a return line on my car. Being a CCQjet and having to pass emissions for the year, it has one. Not sure when they started putting them on, but will my stock lines support the added fuel pressure? My carb now only pulls 7psi max.

 

the carb lines will work for tbi with no problems-when
i switched my '82 from carb to CFI (usually the swap is
the other way LOL),i first just used an inline pump with
the carb lines-worked fine. later i got a CFI tank/pump/
pickup and used '85 2.8 v6 fuel lines because those run
straight along the LH frame instead of crossing over the
tranny to the RH side. The fuel injection tanks have a
plastic slosh tray in them to keep fuel from sloshing away from the pump intake when fuel is low,unlike a
carb with it's float bowl,FI will cut out if fuel pressure
is lost for a moment.

 

I'm just not having much luck with this carb set up and it's getting on my nerves. So I started looking at doing the swap. Did you have to change your ECM to accomodate your CFI?

 

The stock carb ECM will have to go as it cannot control the TBI. Some good choices for replacement are RBobs EBL (modified TBI ECM), or a TBI PCM (part number '8625, '7727, etc.). Id stay away from using a stock TBI ECM as they are not the best from a performance standpoint. Also keep in mind that you will need to do some tuning afterward to get the most out of your setup.

 

Also you are best served going to a TPI pump due to your mods. Now the question has to be reasked if your lines will support 20-30 lbs FP plus a margin of safety. Maybe just the pressure line needs to be replaced? Is it steel line? Is there a connection at front of engine that is synthetic? Maybe only that needs to be replaced?

 

Everyone I"ve talked to says that the stock carb lines will easily support TBI fuel pressure because I'm running the factory stainless lines. I'm running a 3/8 fuel hose to my regulator and steel braided lines to the carb.

 

Is it best in this case just to get the entire harness? Or can I make the 2 work together?

 

when i 1st did my C/F conversion,i only used the engine
harness that connects to the ECM-adapted it to the rest
of the car,several inline fuse holders etc,etc...wasn't too
big a deal as i am very used to electrical work.
Later,once i was satisfied with the c/f system i installed
the rest of the original c/f wiring harness,including fuse
panel When i 1st converted,did not install any of the
smog control valves,egr etc.,so didn't run right at 1st:
reinstalled all the smog except A.I.R.-Then it ran good.
Also had the whole injection system from an '87 350
1/2 ton pickup that i thought about using,but that
was not as exotic or "period correct" as the crossfire
and i had heard they didn't have the best part throttle
mixture distribution,the '87 setup used a 7747 ECM.
Did my conversion back in 1994,has been very,very
reliable.