Timing causing dieseling??
Thread Starter
Staging Lane
Joined: Oct 2011
Posts: 64
Likes: 0
From: Northern Ca
Timing causing dieseling?? So my car diesels kinda bad.. Ive checked for intake leaks- no leaks. So leads me to think it may be the timing?? I had a buddy adjust the timing and I am thinking its all off... Any help or ideas would be GREATLY APPRECIATED....
29@0
26@1000
35@2200
38@4000
37@5700
36@6100 to 7200
Does this seem right?? As far as initial timing I am thinking way too much?
Some specs of setup.
66 chevelle
3100lbs
3.73s
T56
Cam: 231/239 gross 617/624 lobe 113
Holley hp ultra 750
Vic jr intake
Afr 210 heads
ANY HELP WOULD BE FREAKIN AWESOME
29@0
26@1000
35@2200
38@4000
37@5700
36@6100 to 7200
Does this seem right?? As far as initial timing I am thinking way too much?
Some specs of setup.
66 chevelle
3100lbs
3.73s
T56
Cam: 231/239 gross 617/624 lobe 113
Holley hp ultra 750
Vic jr intake
Afr 210 heads
ANY HELP WOULD BE FREAKIN AWESOME
Thread Starter
Staging Lane
Joined: Oct 2011
Posts: 64
Likes: 0
From: Northern Ca
Right now I run 91 octane.. From what i calculated i have 10.2-1 compression so I thought 91 would be fine. And when you say needs to come down up top do you mean at higher rpm timing needs to be lower?
I agree with zones, too much timing at low RPM. Less timing should make the car easier to start too. You may need to readjust your idle mixture when you drop the timing.
Higher octane gas will help with the dieseling problem. I think we have 93 octane here.
Higher octane gas will help with the dieseling problem. I think we have 93 octane here.
So my car diesels kinda bad.. Ive checked for intake leaks- no leaks. So leads me to think it may be the timing?? I had a buddy adjust the timing and I am thinking its all off... Any help or ideas would be GREATLY APPRECIATED....
29@0
26@1000
35@2200
38@4000
37@5700
36@6100 to 7200
Does this seem right?? As far as initial timing I am thinking way too much?
Some specs of setup.
66 chevelle
3100lbs
3.73s
T56
Cam: 231/239 gross 617/624 lobe 113
Holley hp ultra 750
Vic jr intake
Afr 210 heads
ANY HELP WOULD BE FREAKIN AWESOME
29@0
26@1000
35@2200
38@4000
37@5700
36@6100 to 7200
Does this seem right?? As far as initial timing I am thinking way too much?
Some specs of setup.
66 chevelle
3100lbs
3.73s
T56
Cam: 231/239 gross 617/624 lobe 113
Holley hp ultra 750
Vic jr intake
Afr 210 heads
ANY HELP WOULD BE FREAKIN AWESOME
Thread Starter
Staging Lane
Joined: Oct 2011
Posts: 64
Likes: 0
From: Northern Ca
Yep the car has issues starting too.. I will change the timing to what zones suggested n see what happens. Also no vacuum setup. I will change that too. Ill get this done inna couple hours, i will post results. Thanks for the input all!
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Verdad Gallardo I often run 38 to 44 degrees total timing (including vacuum advance) on engines at idle depending on how they "like" it. I also like this kind of timing at a light cruise also.
Thread Starter
Staging Lane
Joined: Oct 2011
Posts: 64
Likes: 0
From: Northern Ca
So I set up the timing and the map table to the settings and still dieseling... Maybe I need an instuctional video or something??
This is what its doing
The gauge display-
2 bar setup-
(guage right most) 19psia
(center) 19 deg
(left most) 700 rpm
Maybe it needs better gas??
This is what its doing
The gauge display-
2 bar setup-
(guage right most) 19psia
(center) 19 deg
(left most) 700 rpm
Maybe it needs better gas??
Thread Starter
Staging Lane
Joined: Oct 2011
Posts: 64
Likes: 0
From: Northern Ca
Turned map off n still bad... Maybe i do have an intake leak.. I will recheck and see where im at. The timing is jumping all over the place. Rpms jump from like 30-70 rpm at times.. Is this normal?
Thread Starter
Staging Lane
Joined: Oct 2011
Posts: 64
Likes: 0
From: Northern Ca
Im assuming it DOES have a leak... I just read another article where some guy was running 40 deg at idle?? He said with 87 oct on 200 water temp. That sounds nuts, but i will try this next.
Thread Starter
Staging Lane
Joined: Oct 2011
Posts: 64
Likes: 0
From: Northern Ca
Ok so heres an update.. Its almost 1030 and imma try again 2mrw.
Last thing we did today-
We hooked up the map sensor and zeroed out the map table.
Gradually added more and more timing until we got to 52 deg at idle. Tried it several times and lo n behold the car shuts off! We still think its too much timing at idle so brought it back down to 40 at idle and 2mrw we will mess with the carb and hopefully we get this figured out.
Any input or any more ideas?? Thanks again for all the help.
Last thing we did today-
We hooked up the map sensor and zeroed out the map table.
Gradually added more and more timing until we got to 52 deg at idle. Tried it several times and lo n behold the car shuts off! We still think its too much timing at idle so brought it back down to 40 at idle and 2mrw we will mess with the carb and hopefully we get this figured out.
Any input or any more ideas?? Thanks again for all the help.
I didn't think the timing alone was going to fix it. Octane is usually what does.
Do you have a wideband? What are your AFR at idle and slightly off idle? I had and old car that had a solenoid in the carb idle circuits to turn them off and prevent dieseling. If your car is sucking too much gas through at idle combined with high compression and low octane gas, that is what causes dieseling.
Did you readjust the idle speed and mixture when you dropped the timing? Primary and secondary? What do the plugs look like?
Do you have a wideband? What are your AFR at idle and slightly off idle? I had and old car that had a solenoid in the carb idle circuits to turn them off and prevent dieseling. If your car is sucking too much gas through at idle combined with high compression and low octane gas, that is what causes dieseling.
Did you readjust the idle speed and mixture when you dropped the timing? Primary and secondary? What do the plugs look like?
Every car is different.
The ignition doesn't have much to do with dieseling when it is off. If the engine gets too hot and/or has carbon fouled combustion chambers, that is what causes it. Beyond that it is fuel delivery and octane, IMO.