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Thread: Question about rebuilt engine
02-18-2010, 08:58 PM #1
Question about rebuilt engine
I just rebuilt my 5.7 350 and I have some questions about it. Once i first start her up, the engine idles kind of roughly and the exhaust smells of gasoline. Once the engine warms up, the rough idle goes away, but the gas smell still persists. Any ideas on this? I have already adjusted the idle and messed with the timing some. I'm still thinking its a timing issue.
93 k1500 5.7 350 tbi
Forged flat top pistons
edelbrock 3702 cam
k&n cold air intake
Holley 670 cfm throttle body
Throttle body spacer
02-18-2010, 09:07 PM #2
IT sounds like it could be a timing issue. Have you tried adjusting the throttle? Maybe it's dumping too much fuel at idle and needs set back a bit. That could be causing a rough idle also because the air/fuel mixture is too rich with fuel.
The fool learns not from the wise man, but the wise man from the fool.
2004 Silverado 4x4 (Suzie)
6" Fabtech Suspension Lift
35" NITTO Terra Grapplers
18" MB Wheels Predators
Thrush Turbo Series Mufflers
on true dual exhaust
Grille by Option Racing
Finally getting torn down to the frame.
02-18-2010, 10:44 PM #3
Yeah I have tried adjusting the throttle. Its weird because it like starts to cut out once you get into the higher rpms when its a little cold, but like I said once it warms up this is not an issue. I suppose i should try using a timing light to get it just right.
02-18-2010, 11:37 PM #4
it could also be the coolant temp sensor, if they go bad it can cause the computer to dump fuel in at start up to the point of flooding the engine99 K1500 Suburban LT "THE BEAST"
Hypertech III, K&N, true dual
02-19-2010, 10:04 AM #5
Pretty much all of my sensors are new. The temp sensor is the newest one I have replaced.
02-19-2010, 11:10 AM #6
You may want to check the spark plugs. Just becasue they are new doesnt mean they cant fail. if you have the smell of gas in the exhaust it could be becasue it isnt being burned.Jeep Recovery Vehicle.
02-21-2010, 04:23 PM #7
Tested all of the spark plugs and they are good as well as the wires. I guess the only thing it could really be is timing.
02-26-2010, 06:24 AM #8
You say it was a rebuild...
How many miles were on it?
Still have the stock Intake Manifold?
Stock Exhaust Manifold or Headers?
Still have the CAT's?
Did you give the throttle body a good cleaning?
Setting the Timing is a must. Also check the Idle Air Control Valve. Clean it for sure, but for $20 you can replace it.
I did a rebuild, and I still can smell some gas in the exhaust. But that is cuz' I cut off the CAT's and the Dual Exhaust dumps out just behind the cab.Pavement sucks... :grrrrrr:
1994 K1500 4x4 Ext. Cab
PCM chip and Xenon 8000k bulbs
350cu.in bored over .050"
balanced Crank, 10:1 compression
Flat top pistons,cam,ported heads
Option Racing Cold Air Intake
Holley Throttle Body Spacer
Accell Igition, 45kv coil
FloTech Headers, no CATs, dual exhuast
Goodyear Silent Armor A/T 305/70-16
Pioneer SupertunerIII CD USB Bluetooth
Kicker ZX200.2 ZX Amp
Kicker Audio COMP 10" Subwoofer
02-26-2010, 10:52 AM #9
03-07-2010, 01:21 PM #10
- Join Date
- Dec 2009
- Seabrook Texas
Are you getting any codes to indicate that it is rich or lean? Usually if your far enough out of tolerance to smell gas its popping a rich code for sure?
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