What does the distributor look like? Can you post a pic?
Why is it so hard to get good advice !!???
- Thread starter Kern Dog
- Start date
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racerhog
RacerHog likes his Mopars
Pull a plug and look at it....
Did you put the Barry Grant 850 on it? 92&93 6.5... I'm thinking it fueling out the exhaust?
Just a thought....
Did you put the Barry Grant 850 on it? 92&93 6.5... I'm thinking it fueling out the exhaust?
Just a thought....
Yeah, it is the very same Grant/Demon 850 I have had for 10 years. I just went up one jet size and changed the PV.
I guess the wideband guage will tell the tale if it is too lean. Pulling the plugs when the engine is still hot? Hell no. I've been burned before. 2 inch headers don't leave a lot of room to work around.
I guess the wideband guage will tell the tale if it is too lean. Pulling the plugs when the engine is still hot? Hell no. I've been burned before. 2 inch headers don't leave a lot of room to work around.
-Sledgehammer-
Mopar Performance
glowing headers is the fuel burning in the tubes... If you have a 4 corner idle carb lean them out and start there. As far as the pump I have been 9's with a 150gph pump.
I was busy most all day with other stuff, but I was able to reset the timing to 33 degrees total and check the vacuum reading. The park/neutral 1000 rpm reading was 10 inches, dropping to 4 when I was in gear at 700 rpms.
I did not adjust the idle mixture screws. I justa wanted a baseline number to know where I started. Seems to me if I tweaked the idle mixture screws a bit, the vacuum could come up. The 4" of vacuum is lower than the 6.5 power valve, but I suspect that at cruise, my vacuum would be higher than at idle.
Tommorow I'm going to install the wideband guage. This will help me determine what effect each change has on everything. I've read that the goal is for 14.7 Air/Fuel at cruise and 12.5 to 13.0 at WOT.
I did not adjust the idle mixture screws. I justa wanted a baseline number to know where I started. Seems to me if I tweaked the idle mixture screws a bit, the vacuum could come up. The 4" of vacuum is lower than the 6.5 power valve, but I suspect that at cruise, my vacuum would be higher than at idle.
Tommorow I'm going to install the wideband guage. This will help me determine what effect each change has on everything. I've read that the goal is for 14.7 Air/Fuel at cruise and 12.5 to 13.0 at WOT.
72BBSwinger
Well-Known Member
The worst vice in the world is ad-vice. I sure hope you accomplish your original goal of no ping.
*******UPDATE*******UPDATE*********UPDATE********
I got the wideband guage installed. I haven't jumped into tuning much yet, just wanted to pop in to post this:
Engine as is without touching anything: 9 1/2 inches idle vacuum at 1000, 4 in gear at 700-800. Idle mixture screws were only 1 1/4 turns out from being seated. IN GEAR the guage reads between 15.0 and off the guage which tops out at 18.0. When I revved it above idle, it pegged past 18.0!
I had a feeling it was lean!
I seated the idle mixture screws, then backed them out a full 2 turns. Idle vacuum went up to a solid 10+ with 5+ in gear. At idle, the guage reads between 14.0 and 15.0. It still pegs when I lean into the throttle.
Here is a thought: The primary side is running lean with the 86 jets. Being that I have 5.0" of vacuum and a 6.5 Power Valve, I think the PV may be covering for the UNDERjetted primaries. When I rev the engine, there is no additional fuel to keep the Air/Fuel ratio in check.
Sound right so far?
I got the wideband guage installed. I haven't jumped into tuning much yet, just wanted to pop in to post this:
Engine as is without touching anything: 9 1/2 inches idle vacuum at 1000, 4 in gear at 700-800. Idle mixture screws were only 1 1/4 turns out from being seated. IN GEAR the guage reads between 15.0 and off the guage which tops out at 18.0. When I revved it above idle, it pegged past 18.0!
I had a feeling it was lean!
I seated the idle mixture screws, then backed them out a full 2 turns. Idle vacuum went up to a solid 10+ with 5+ in gear. At idle, the guage reads between 14.0 and 15.0. It still pegs when I lean into the throttle.
Here is a thought: The primary side is running lean with the 86 jets. Being that I have 5.0" of vacuum and a 6.5 Power Valve, I think the PV may be covering for the UNDERjetted primaries. When I rev the engine, there is no additional fuel to keep the Air/Fuel ratio in check.
Sound right so far?
I switched the 3.5 PV back in. The idle readings went down to 13.0 to 13.6. Kinda odd for it to richen up when I went to a smaller rated PV. I turned the idle mixture screws in to where they sit at 1 1/4 turns out again and the A/F reading came back to the 14.5-14.9 range.
NOW it goes off the charts lean when I put it into gear or hold the brake and ease on the throttle.
I thought I knew a little about carburetors, but tell me if i have this right:
* The IDLE circuit works when the primary throttle blades are closed. The main jets are NOT in play when in the idle circuit.
* The primary jets begin to function when the engine is put under a load and the primary throttle blades open.
If the above is true, would that mean that my primary jetting is still too lean? I understand that you are supposed to make only one change at a time which is why I only changed the power valve when I had the bowl off.
Looking at the gaskets I used, they actually are fine. They are a rubber like red gasket that came in a Demon rebuild kit I had.
NOW it goes off the charts lean when I put it into gear or hold the brake and ease on the throttle.
I thought I knew a little about carburetors, but tell me if i have this right:
* The IDLE circuit works when the primary throttle blades are closed. The main jets are NOT in play when in the idle circuit.
* The primary jets begin to function when the engine is put under a load and the primary throttle blades open.
If the above is true, would that mean that my primary jetting is still too lean? I understand that you are supposed to make only one change at a time which is why I only changed the power valve when I had the bowl off.
Looking at the gaskets I used, they actually are fine. They are a rubber like red gasket that came in a Demon rebuild kit I had.
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