Dies with throttle
12-31-2014, 07:12 PM
#1
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Dies with throttle Hi All, happy new year to you all.
I have a 02 Camaro that has a problem that I just can not solve. I can get it to fire, idle rock steady at 950, rev up and come back to idle without dips or stumbles, idles at 14.2-14.5 afr all day long, it will go into gear without issue but as soon as you touch the throttle to move off it just dies straight away.
The car is a 408 with TFS heads, MS3 cam, fast 92 manifold and a Fast 92 throttle body and a TH400. I read about people having issues with the small IAC opening on the FAST 92 TB's so we opened that up massively. For me to get the DYN AIR and Desired air to line up I had to move the effective area table across to 52 from about 16 and increase the numbers by nearly double. I have the IAC counts sitting around 40-50 when hot but it doesn't seem to open up far enough to start the car, sometimes it needs some throttle to help it. If I open the TB blade any more the IAC drops too low. I have tried adding throttle follower.
Attatched is the tune in HPT if anyone wants to take a look and offer some advice. There is a log aswell, I thought it was one with the stalling shown but it looks like this one is all in park.
Any help would be appreciated, been at this for 3 days with no luck.
I have a 02 Camaro that has a problem that I just can not solve. I can get it to fire, idle rock steady at 950, rev up and come back to idle without dips or stumbles, idles at 14.2-14.5 afr all day long, it will go into gear without issue but as soon as you touch the throttle to move off it just dies straight away.
The car is a 408 with TFS heads, MS3 cam, fast 92 manifold and a Fast 92 throttle body and a TH400. I read about people having issues with the small IAC opening on the FAST 92 TB's so we opened that up massively. For me to get the DYN AIR and Desired air to line up I had to move the effective area table across to 52 from about 16 and increase the numbers by nearly double. I have the IAC counts sitting around 40-50 when hot but it doesn't seem to open up far enough to start the car, sometimes it needs some throttle to help it. If I open the TB blade any more the IAC drops too low. I have tried adding throttle follower.
Attatched is the tune in HPT if anyone wants to take a look and offer some advice. There is a log aswell, I thought it was one with the stalling shown but it looks like this one is all in park.
Any help would be appreciated, been at this for 3 days with no luck.
01-01-2015, 11:03 PM
#3
01-01-2015, 11:13 PM
#4
Again I don't know if this is your problem but I'll further explain what I'm thinking.
When the engine is not under load and you depress the gas pedal it will usually rev with very little extra fuel needed but under load a carb for example has an accelerator pump that will manually add a shot of fuel to the sudden rush of air that is coming in as the throttle blades open. On a fuel injected engine you don't have an accelerator pump so the computer must command the enrichment, Without it or if it's set to low you will have a stumble off idle or it will just plain die from going dead lean. Again I don't know if this is your problem but it very well could be.
When the engine is not under load and you depress the gas pedal it will usually rev with very little extra fuel needed but under load a carb for example has an accelerator pump that will manually add a shot of fuel to the sudden rush of air that is coming in as the throttle blades open. On a fuel injected engine you don't have an accelerator pump so the computer must command the enrichment, Without it or if it's set to low you will have a stumble off idle or it will just plain die from going dead lean. Again I don't know if this is your problem but it very well could be.
01-02-2015, 01:41 AM
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Wide band stays right around 14.5. - 14.0, I think I have it solved, I changed the throttle follower multiplier table in the 1200 and 1600 rpm to 1.5 and 2.0 and that seems to have stopped the stalling, it just hunts a little then settles back at a solid 950rpm.