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TQ tuning issue using M1 intake (SB stroker)
#825953
10/10/10 01:24 AM
10/10/10 01:24 AM
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Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
Moparmal
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Anyone had problems running a TQ on a M1 SB ?
Specifically, the low speed / idle circuit runs waaaay lean , and no amount jetting up or rod changes has an effect.
Anyone got any solutions so I can keep using this carb?
67 RO23 clone with 6.1 SRT Hemi and dual quads. Soon to have Drag Pak induction and Throttle body.
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Re: TQ tuning issue using M1 intake (SB stroker)
[Re: ScottSmith_Harms]
#825955
10/10/10 03:00 AM
10/10/10 03:00 AM
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Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
Moparmal
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SSH - I just swapped the M1 in - I had a vac guage on it this morning - its reading around 13 at 900 rpm, but it does waiver a little beween 10 and 13. I did the leak test with fluid around the intake flange but it had no effect....  As soon as you blip the throttle, and as the rpms come down, the Vac drops to almost zero and the engine flutters and almost dies. Because its been so badly behaved at low speed, I assumed it was the low speed circuit - (I checked all the carb gaskets and this carb ran 12.6 at the track last weekend on an LD340) Are you saying that the TQ shouldn't be effected by the M1 this badly?
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Re: TQ tuning issue using M1 intake (SB stroker)
[Re: ademon]
#825958
10/10/10 03:50 AM
10/10/10 03:50 AM
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Melbourne.....Oz-land
Moparmal
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ademon - in a round about way you've answered the problem. I needed to know if these SP intakes caused issues with TQs - clearly as your running one on a non stock 360 , this tells me the TQ circuitry can work fine on an M1. Obviously my problem is elsewhere - and I'm thinking SSH is right, and its a Vac leak. I've had TQs a long time - there's no issue with the calibration - except that I knew something was up when I had to go so rich on the primaries and it still showed lean on the AF guage. I just hope this intake is not porous - I bought it off a member here. 
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Re: TQ tuning issue using M1 intake (SB stroker)
[Re: ademon]
#825964
10/10/10 04:46 AM
10/10/10 04:46 AM
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Melbourne.....Oz-land
Moparmal
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@ ademon - I realised I had a problem when I went to .107th primaries and it showed lean at 16 AF on the AF guage at 2100 rpm in top gear. Please note: Last weekend I ran 12.6 with the LD340 - AF guage read 12.5 at idle, 14-15 at cruise, 12.4 at WOT in 3rd. When you see that the WB AF guage shows pretty accurate readings - I start to worry when I have 16s AF and I'm running .107 primaries with the tree on 5 turns (1996 rods too) !!!  The car drives like a pig as well -fluttering off idle and other issues. To run it that rich and still show a lean - ish mixture - there's something not right.
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Re: TQ tuning issue using M1 intake (SB stroker)
[Re: Moparmal]
#825965
10/10/10 11:56 AM
10/10/10 11:56 AM
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Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
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Posts: 12,419
Kalispell Mt.
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It is possible to be rich and show lean if the mix is not being ignited. The sensor reads the oxygen not the fuel and if the mix does not burn it will read that unburned oxygen as a lean condition. I think it would be worthwhile to throw a set of new plugs in, mabey one got fouled out then you started throwing fuel at it to cure the lean condition and wreaked all kinds of havok on it. The single plane intake will give less signal to the carb and require a touch more fuel. I would try putting a piece of wire in the idle air bleed and see if that helps, if it does then you need to shrink the air bleeds. It sounds like your problems are with the idle circuit and since it is not makeing the proper air fuel mix then when you open the throttle there is not enough signal to get the other circuits pulling fuel properly. But again before I changed the carb any more I would check the ign system and throw in some new plugs. 
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: TQ tuning issue using M1 intake (SB stroker)
[Re: Diplomat360]
#825973
10/11/10 05:00 PM
10/11/10 05:00 PM
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Melbourne.....Oz-land
Moparmal
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Thanks D360 - I'm not sure I want to go through all that agony  I've done the holes in the butterfly thing a long time back - but this is a case of lean running well off the idle and into the low speed circuit. I might try reducing the air bleed hole size and see if anything improves - Like you - I still can't figure if you are meant to enlarge the idle jets as well as reduce the air bleed size - hopefully Demon Sizzler will chime in again. Id also like to know what the correct base gasket is to use.
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Re: TQ tuning issue using M1 intake (SB stroker)
[Re: Rug_Trucker]
#825976
10/12/10 06:23 AM
10/12/10 06:23 AM
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Melbourne.....Oz-land
Moparmal
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Well I'd like to say its better news - Just to recap, here's how the carb behaved on the DP intake before the swap - Mixture screws 4 turns out
AF - idle was 12.2, Cruise was 14.5 and WOT was 12.5
Vac was 13
Jets were .101 / .138 I had it running pretty darn good. On Sunday after the swap - I had Mixture screws all the way out
13- 16 AFs bouncing around like crazy at idle
Off the scale lean at cruise
Vac bouncing between 9-13 and dropping to zero on deceleration. I swapped on a buddies AVS 650 and all the bad symptoms went away! - it idled at 12.5 and I had steady Vac at 15. This told me it was def a carb issue - not an intake leak. - so here's how I spent my Tuesday evening - Testing of TQ, Replaced the carb flange gasket - improved slightly but still a vacuum variation and running pretty ordinary (Sorry its bad news Dave) - AF was between 13 and 14.5 at idle
Took the holes in the butterflies out to .094th - slightly more even idle but a still way lean and a big Vac drop after blipping the throttle.
Blocked off the air bleeds completely, and the idle settled - it stayed around 12-13 AF and the Vac settled at 14. So.......I thought I had it licked  - till I went for a drive , and - AF dropped to zero when i let off the pedal
AF went to 9s under light acceleration and I blew black smoke. Conclusions - Blocking the air bleeds richened the mixture so it idled better
- but the low speed circuit needs the air from the bleeds to maintain a decent cruise/light accelration mixture
In which case - blocking the bleeds is not going to work.  Next step Would I be right in thinking its not getting enough fuel through the idle circuit? Is this common? In which case, how do I fix it?
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Re: TQ tuning issue using M1 intake (SB stroker)
[Re: Moparmal]
#825977
10/12/10 10:17 AM
10/12/10 10:17 AM
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Joined: Feb 2005
Posts: 5,221
Branson, Mo.
joedust451
super gas
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super gas
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Posts: 5,221
Branson, Mo.
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Quote:
Well I'd like to say its better news -
Just to recap, here's how the carb behaved on the DP intake before the swap -
Mixture screws 4 turns out
AF - idle was 12.2, Cruise was 14.5 and WOT was 12.5
Vac was 13
Jets were .101 / .138
I had it running pretty darn good.
On Sunday after the swap - I had
Mixture screws all the way out
13- 16 AFs bouncing around like crazy at idle
Off the scale lean at cruise
Vac bouncing between 9-13 and dropping to zero on deceleration.
I swapped on a buddies AVS 650 and all the bad symptoms went away!
- it idled at 12.5 and I had steady Vac at 15.
This told me it was def a carb issue - not an intake leak.
- so here's how I spent my Tuesday evening -
Testing of TQ,
Replaced the carb flange gasket - improved slightly but still a vacuum variation and running pretty ordinary (Sorry its bad news Dave) - AF was between 13 and 14.5 at idle
Took the holes in the butterflies out to .094th - slightly more even idle but a still way lean and a big Vac drop after blipping the throttle.
Blocked off the air bleeds completely, and the idle settled - it stayed around 12-13 AF and the Vac settled at 14.
So.......I thought I had it licked - till I went for a drive , and -
AF dropped to zero when i let off the pedal
AF went to 9s under light acceleration and I blew black smoke.
Conclusions
- Blocking the air bleeds richened the mixture so it idled better
- but the low speed circuit needs the air from the bleeds to maintain a decent cruise/light accelration mixture
In which case - blocking the bleeds is not going to work.
Next step
Would I be right in thinking its not getting enough fuel through the idle circuit?
Is this common?
In which case, how do I fix it?
Hey, i think you should "listen" to what demonsizzler advised you to do, that might solve your issues  .
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Re: TQ tuning issue using M1 intake (SB stroker)
[Re: joedust451]
#825980
10/12/10 04:48 PM
10/12/10 04:48 PM
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Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
Moparmal
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Quote:
Hey, i think you should "listen" to what demonsizzler advised you to do, that might solve your issues .
Joedust - Maybe you missed it - here it is......
Quote:
Replaced the carb flange gasket - improved slightly but still a vacuum variation and running pretty ordinary (Sorry its bad news Dave)
ademon - I went back to .101 jets as soon as I swapped the flange gasket - I've had a fair bit of experience with these carbs, but never hit this type of issue before....
I really think its not getting enough fuel, even with the air bleeds fully blocked, I can't get the AF below 12.5 AF
FWIW, if I'd had the mixture screws set like this on the old intake it would have been reading 9s!
.....so I'm wondering what my options are to fatten the idle circuit?
MM
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need to go back to the small jets and get those.107 out, also drop the tree to 1 or two turns, you may have knocked a float or something out of wack when you installed the .107's in..jpg){kind=link}
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