Tony99SS

iTrader: (5)

Just fired up my new engine and it won't idle. I've feathered the throttle for upwards of ten minutes to let it learn the idle, to no avail. It also won't take over half throttle under load without bogging severely.

Here's my setup:
Lunati 383 assembled by HPE
Crane 228/236 @ 600 on a 114 (66* overlap) Crane 1.8 rockers, Comp OE replacement Lifters
ETP stage 3 5.3 heads
Fast90/NW90/SLP 85mm MAF
Racetronic in tank pump
42 lb injectors
Kooks/Randomtech

I have an aeromotive fuel pressure regulator I haven't plumbed in yet (gonna use OE supply and a -6 return from the fuel rail to the tee in back.)

Any suggestions will be appreciated. It isn't throwing any codes, but for some reason the tack is not working. Could that be related??

TIA
Tony

KingWalrus

If it is totally untuned, it doesn't surprise me that it is running pretty poorly. Those 42 lb injectors are delivering some SERIOUS fuel if the computer hasn't been setup to know it has 42 lb injectors.

To answer your question: Yes. You need a tune. The computer can use the 02 feedback to trim itself out to a point. Over half throttle will pretty much put you in the power enrichment fueling zone. If it was running stupid rich before... now will be rediculous.

Get it tuned. It sounds like a nice *** setup!

Tony99SS

iTrader: (5)

I guess you might say it's "completely untuned," the old tune is for a heads and cam 346 (same heads with a TR224.) Obviously the tune won't even be close, but I expected to be able to make the drive to the dyno in Houston (95 miles.) Now I need to rethink that idea, lol.

Any thoughts on the tach not working being an issue? Does the tach run off the CPS or the computer? Again, no SES light, but maybe I have a sensor not working? Or would that put it in open loop and throw the SES?

Thanks for your responses,
Tony

HeapaShifter

iTrader: (2)

You just spent all that money on that engine, don't drive it 95 miles untuned; tow it. It's worth it. The fuel injectors untuned is the biggest problem.

Good set-up though.