A/F Ratio Going Lean!
Thread Starter
3rd Gear Member
Joined: Jul 2006
Posts: 635
From:
A/F Ratio Going Lean!
I put a 650 Dp Holley on my car and im in the process of tuneing it , ipurchased a Innovate Motorspots Wide Band tuner and ran a few test to day , at idle im am at about 12.1 , as i raise therpm solwley up to 5000rpm it it wil raise to a max of about 13.0 , but when i floor it or give it about 1/2 Throttle at a fast rate it jumps lean to about 20.1 at the max for about 1sec and stumbles. Also when i going Downthe road and give it some gase it wil go lean to about 16.1 and stumble.
any idea on what needs to be done?
any idea on what needs to be done?
I think that I would start out by adjusting the accellerator pump linkage arm and maybe swap out the power valve with one that opens a little quicker.Hope that helps.
5th Gear Member
Joined: Jun 2006
Posts: 4,089
From:
RE: A/F Ratio Going Lean!
Accelerator pump cams and squirters would be my first choice. After the engine doesn't stumble just by stabbing the throttle in neutral, start adjusting the power valve when driving the car to get rid of the part throttle stumbles.
3rd Gear Member
Joined: Feb 2007
Posts: 551
RE: A/F Ratio Going Lean!
ORIGINAL: smbikes
I put a 650 Dp Holley on my car and im in the process of tuneing it , i purchased a Innovate Motorspots Wide Band tuner and ran a few test to day , at idle im am at about 12.1 , as i raise the rpm solwley up to 5000rpm it it wil raise to a max of about 13.0 , but when i floor it or give it about 1/2 Throttle at a fast rate it jumps lean to about 20.1 at the max for about 1 sec and stumbles. Also when i going Down the road and give it some gase it wil go lean to about 16.1 and stumble.
any idea on what needs to be done?
I put a 650 Dp Holley on my car and im in the process of tuneing it , i purchased a Innovate Motorspots Wide Band tuner and ran a few test to day , at idle im am at about 12.1 , as i raise the rpm solwley up to 5000rpm it it wil raise to a max of about 13.0 , but when i floor it or give it about 1/2 Throttle at a fast rate it jumps lean to about 20.1 at the max for about 1 sec and stumbles. Also when i going Down the road and give it some gase it wil go lean to about 16.1 and stumble.
any idea on what needs to be done?
The accel pump has 2 positions, try the other one. Also take a vacum reading, subtract 5 and that should put you spot-on for the power valve.
Thread Starter
3rd Gear Member
Joined: Jul 2006
Posts: 635
From:
RE: A/F Ratio Going Lean!
Update: did some changes , pkayed with the air setting and put 31 squirtes in both sidesand got it to idle at 14.7 and revingin neutral it took the gas better with out going so lean but on the road it was still going very lean , did a vac reading and got 11hg , it had a 6.5 Pv in it , whent to the Autoparts and they only had a 4.5 so igot it and tried it and it seems worse,
Ideas??
Ideas??
3rd Gear Member
Joined: Feb 2007
Posts: 551
RE: A/F Ratio Going Lean!
ORIGINAL: smbikes
Update: did some changes , pkayed with the air setting and put 31 squirtes in both sides and got it to idle at 14.7 and reving in neutral it took the gas better with out going so lean but on the road it was still going very lean , did a vac reading and got 11hg , it had a 6.5 Pv in it , whent to the Autoparts and they only had a 4.5 so i got it and tried it and it seems worse,
Ideas??
Update: did some changes , pkayed with the air setting and put 31 squirtes in both sides and got it to idle at 14.7 and reving in neutral it took the gas better with out going so lean but on the road it was still going very lean , did a vac reading and got 11hg , it had a 6.5 Pv in it , whent to the Autoparts and they only had a 4.5 so i got it and tried it and it seems worse,
Ideas??
Remember....subtract 5 from your vac at idle and this is where you should be for your power valve.