IAC / ECU problem.. wtf?
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- First Gear
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IAC / ECU problem.. wtf?
Hi Everyone, I used the FSM's instructions to check the voltage and impedance on the ECU and IAC, nothing seemed that wrong, except that the 7v lines on the ECU rang in at 12v.. any ideas, or any ECUs/IACs for sale
ex-devastated ex-owner of the $5500 parts car!
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- Vikash
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That "7 volts" thing isn't quite correct... The voltage on those wires is actually changing very rapidly from about 0 to about 12, and whatever multimeter the guy writing that chapter of the FSM had gave him a 7-volt reading as its interpretation of that signal.
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- quasi-mod-o
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Yeah,
It should be working fine. And what makes you think the ECU could be an issue? I've got a '90 ECU I can send you if you want to try it out. You can pay me only if you keep it...
It should be working fine. And what makes you think the ECU could be an issue? I've got a '90 ECU I can send you if you want to try it out. You can pay me only if you keep it...
1974 Porsche 914 Cam Am Limted Edition AKA the Bumble Bee
1973 Porsche 914 2.0 l -Suby swap pending
1968 Porsche 911t survivor 47k original miles
2000 2.5RS daily driver.
1999 2.5RS w/ 50+ extra whp
Suby Hai!
1973 Porsche 914 2.0 l -Suby swap pending
1968 Porsche 911t survivor 47k original miles
2000 2.5RS daily driver.
1999 2.5RS w/ 50+ extra whp
Suby Hai!
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- First Gear
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No logical reason, just that after trying everything else, seems like a good last option. With the ECU unplugged, the engine cranks much smoother and rhythmically than with it in, presumably because of some sort of timing adjustments the ECU is doing, or who knows. Also, I realized I'd routed the cam sensor wire under the manifold, rather than around the outside. It's not crushed like I'd thought it might be, but its a tight fit.. could inductive interference be doing this?? Basically, I want to try a new IAC, a new ECU, and a new cam sensor, and if that doesn't fix it, just give up and either have someone else try to fix it, or sell it to someone who wants to/has space to tinker. As much as everyone's support keeps extending this rope, I really do think I'm at the end of it, finally.
ex-devastated ex-owner of the $5500 parts car!
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- Vikash
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It's cranking more rhythmically because every rotation is identical. When the ECU's in, you get some combustion, which makes some rotations different from others.With the ECU unplugged, the engine cranks much smoother and rhythmically than with it in, presumably because of some sort of timing adjustments the ECU is doing, or who knows.
Doing what?could inductive interference be doing this??
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212