Subframe motor mounts.
#61
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I am a bit loathed to add anything but I will anyway. I am aware There is a lot of input here.
The v12 Has a closed throttle map in the ECU separate from the running map. This was for emissions and can make the engine hunt between about 900 and 1500rpm. Is this the symptom?
The v12 Has a closed throttle map in the ECU separate from the running map. This was for emissions and can make the engine hunt between about 900 and 1500rpm. Is this the symptom?
#62
#63
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heres the problem. the engine isnt drawing enough vacuum to calculate fuel correctly, (about 15in/hg) so when you you get it to run ok, and plug the ECU in it starts adding fuel to make up for the decrease in vacuum, which in turn causes the vacuum level to drop, which causes more fuel to be added, and less vacuum and more fuel and less vacuum until the engine is barely running.
its a vicious cycle.
whoever figures out how to get the vacuum from 15in/hg to 25 in/hg wins.
its a vicious cycle.
whoever figures out how to get the vacuum from 15in/hg to 25 in/hg wins.
#64
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I am a bit loathed to add anything but I will anyway. I am aware There is a lot of input here.
The v12 Has a closed throttle map in the ECU separate from the running map. This was for emissions and can make the engine hunt between about 900 and 1500rpm. Is this the symptom?
The v12 Has a closed throttle map in the ECU separate from the running map. This was for emissions and can make the engine hunt between about 900 and 1500rpm. Is this the symptom?
May I suggest that you block off the throttles and see what happens if you start it. It will ether prove there is a vac leak and you have not found it, or that there is not. If you are sure there is one, it should be big enough to start the car and noisy enough to find!
Greg
Greg
#65
#67
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again. its not a vacuum leak. both throttle bodies totally closed and it dies.
while i was checking for vacuum leaks it started surging again after about a 5 minute run. again its like throwing a switch. it just happens out of nowhere without warning. between 300-1,000 rpm and not a rev higher. about 5 more minutes of that and it died on its own.
so about 10 minutes of tinkering and i cant get it started again.
while i was checking for vacuum leaks it started surging again after about a 5 minute run. again its like throwing a switch. it just happens out of nowhere without warning. between 300-1,000 rpm and not a rev higher. about 5 more minutes of that and it died on its own.
so about 10 minutes of tinkering and i cant get it started again.
#68
#69
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Here's what I was wondering: The vac advance on these cars is supposed to have a small leak, so they won't hold vacuum. I recall that you changed yours, and if you put in one that does not have the small leak, the moment the engine starts and creates vacuum, it will pull the advance, altering the timing and causing the engine idle to change. When the timing gets beyond a certain point it dies out, the vacuum is lost and timing returns to where the engine can run, causing the surging.
Maybe I'm way off, but it's worth a shot.
Maybe I'm way off, but it's worth a shot.
#71
Join Date: Jul 2010
Location: Austin tx and Daytona FL.
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have you done a compression test,? just to see if cylinders are resonably close.
what if it has a dropped seat, and causing backfires, crazy fluctuating manifold pressures.
forum diagnosis can be to much information overload. personally, i would have to shut off all outside opinions, back away for couple days, and just let things ride for a while.
sounds like its making you cra%y, you cant think smoothly when you under PEER pressure!! young man.
what if it has a dropped seat, and causing backfires, crazy fluctuating manifold pressures.
forum diagnosis can be to much information overload. personally, i would have to shut off all outside opinions, back away for couple days, and just let things ride for a while.
sounds like its making you cra%y, you cant think smoothly when you under PEER pressure!! young man.
#73
#74
#76
#77
#78
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Have you verified every wire yet? Use a meter and wiring diagram and do the checks at ECU.
Have you done compression test yet? Do it properly. All plugs out, throttles held open. Battery charger on battery. Crank and stop after pressure stops building. Write down the numbers.
Do a leak down test too.
Have you fixed the AAV hoses and set throttle plates properly? If not you need to do that.
Have you verified fuel pressure yet?
I posted a list on the other post you made before you hijacked this one and you hadn't done half of the possible items. As I talked to you about make a list and work throughout the list. You are just randomly trying stuff and hoping for a silver bullet. The only way to fix this is to make a list of possibilities and one at a time check your items on the list. Obviously start with easy and work toward hardest. I posted a list on your other thread.
#79
#80