Revs fine in park, absolute dog in drive
#971659
04/11/11 11:14 PM
04/11/11 11:14 PM
|
Joined: Aug 2003
Posts: 4,481 Mesa, AZ
Pat_Whalen
OP
super gas
|
OP
super gas
Joined: Aug 2003
Posts: 4,481
Mesa, AZ
|
Kind of curious as to what could cause my current issue. Put a carb back on my 440 in the interest of getting it running again. Truck starts and idles fine (albeit a little bumpy, but it always did). AFR is right around ~14.5 at idle. It'll rev quickly in park and doesn't seem to have any issues. During the pre-drive tuning, the truck was idling on it's own and I heard a loud "POP", the truck dropped it's idle to around 200, almost stalled, sat like that for a couple of seconds, and the came right back up on it's own. Kind of odd. Transmission is recently rebuilt (less than 300 miles on it) and ran fine before the carb went on (previously EFI). When I shift into drive and start moving forward, the engine doesn't seem to want to rev, and if I force it, it'll backfire loudly and lurch. I'm not sure if I'm redicously lean and rich, as I know an O2 sensor can be fooled in the extremes of either situation. My kickdown is properly set and operating. My Edelbrock 1406 has the IMS turned 2.5 times out. Is there anything I can do to try and figure out if this is engine related or transmission related? Thanks all
|
|
|
Re: Revs fine in park, absolute dog in drive
[Re: superbyrd]
#971661
04/11/11 11:34 PM
04/11/11 11:34 PM
|
Joined: Aug 2003
Posts: 4,481 Mesa, AZ
Pat_Whalen
OP
super gas
|
OP
super gas
Joined: Aug 2003
Posts: 4,481
Mesa, AZ
|
Quote:
what is your initial timing set at?
~10*
|
|
|
Re: Revs fine in park, absolute dog in drive
[Re: superbyrd]
#971663
04/11/11 11:47 PM
04/11/11 11:47 PM
|
Joined: Aug 2003
Posts: 4,481 Mesa, AZ
Pat_Whalen
OP
super gas
|
OP
super gas
Joined: Aug 2003
Posts: 4,481
Mesa, AZ
|
Quote:
try putting some or alot more initial timing in it and see if it helps or not.
Will do Ill report back in a bit.
|
|
|
Re: Revs fine in park, absolute dog in drive
[Re: ph23vo]
#971665
04/12/11 12:43 AM
04/12/11 12:43 AM
|
Joined: Aug 2003
Posts: 4,481 Mesa, AZ
Pat_Whalen
OP
super gas
|
OP
super gas
Joined: Aug 2003
Posts: 4,481
Mesa, AZ
|
Quote:
...also double ck 5 and 7 plug wires arent crossed its easy to do..
A lot of the simple things are easily eliminated- the truck was running well with the EFI on it. The only thing changed was fuel induction. But I will be checking the little things like plug gap and color.
|
|
|
Re: Revs fine in park, absolute dog in drive
[Re: superbyrd]
#971668
04/12/11 01:22 AM
04/12/11 01:22 AM
|
Joined: Aug 2003
Posts: 4,481 Mesa, AZ
Pat_Whalen
OP
super gas
|
OP
super gas
Joined: Aug 2003
Posts: 4,481
Mesa, AZ
|
Quote:
the smaller carb will help with throttle response on a late smog-era BB, you will have to find a happy medium with timing between bog and detonation with low compression and 87 octane fuel. trial and error,trial and error.
So theoretically, I just continue increasing initial timing until things start going downhill? Would 16* be a stretch?? I believe the small blocks start around there somewhere, but I didn't know if a big block likes that much advance.
|
|
|
Re: Revs fine in park, absolute dog in drive
[Re: superbyrd]
#971670
04/12/11 08:11 AM
04/12/11 08:11 AM
|
Joined: Jan 2003
Posts: 24,562 Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
|
Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
|
Quote:
run as much timing as fuel/octane will allow.timing is free HP. once it starts detonating,back it down. i wouldn't push it past 15 degrees inital. engine running temp will rise slightly with your increase as well. watch all the variables. also,make sure with that eddy carb,that your fuel pressure is at 5psi or under. you might be suprised what a stock mechanical fuel pump puts out. if its over 5psi,get a simple parts-store mr.gasket or holley adjustable pressure regulator. eddys are twitchy at anything over 5psi.
What he said, I'd also think you might want all your timing in early with a big rig like that...36* all in at 2400???? Sounds like you are working it all out.
|
|
|
Re: Revs fine in park, absolute dog in drive
[Re: Pat_Whalen]
#971671
04/12/11 08:43 AM
04/12/11 08:43 AM
|
Joined: Apr 2010
Posts: 4,154 bethlehem pa
mikemee1331
master
|
master
Joined: Apr 2010
Posts: 4,154
bethlehem pa
|
Quote:
Transmission is recently rebuilt (less than 300 miles on it) and ran fine before the carb went on (previously EFI).
maybe it's just me but i would be looking at 'what has changed'.
|
|
|
|
|