427 SBC Back to not starting. Changing PWs no effect..
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427 SBC Back to not starting. Changing PWs no effect..
Had it running last week, and in the mist of trying to figure out base timing, something has changed. Despite returning to a running restore point tune, it won't fire. Spark plugs are wet, and now I notice that my crank signal is inverted. Ignition is HEI 8 hooked up to MS3/3X.
Only changes since it was running was resetting the VR sensor to align at 0 BTDC. Would not start, realigned it back to 10 BTDC, and still no spark.
Logs attached.
Only changes since it was running was resetting the VR sensor to align at 0 BTDC. Would not start, realigned it back to 10 BTDC, and still no spark.
Logs attached.
Last edited by 91blkvette on Sun Nov 23, 2014 3:50 pm, edited 2 times in total.
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Re: 427 SBC No ignition and crank signal inverted?
Does it spark in "Test Mode"? Where are you checking for spark while cranking, at a plug wire or at the coil? If you are testing at a plug wire, check also at the coil.
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Re: 427 SBC No ignition and crank signal inverted?
The "inverted" behavior is simply how TunerStudio visualizes a single ended signal.
Does it spark if you disconnect the "B" pin and crank it? If so, what timing do you see?
Does it spark if you disconnect the "B" pin and crank it? If so, what timing do you see?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
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Re: 427 SBC No ignition and crank signal inverted?
Spark is back, problem appears related to a bad dist to coil plug wire. Tested +12v and tach wires going into the coil and the voltage is as expected.
Matt, checked cranking timing, and it's reporting 12 degrees, which is what I expect as the dist is aligned at approx 10 degrees.
Matt, checked cranking timing, and it's reporting 12 degrees, which is what I expect as the dist is aligned at approx 10 degrees.
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Re: 427 SBC No ignition and crank signal inverted?
Still not firing. Plugs wet.. take them out to check spark..sparks on cranking.
Must be the cold weather messing things up. Well on to messing with pulse widths..
Must be the cold weather messing things up. Well on to messing with pulse widths..
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427 SBC No start again. Changing PW settings no effect
Still no start. Increasing and decreasing PWs not having any effect. Used a tune that at least resulted in a running engine 2 weeks ago.
Cranks, wont start despite adding throttle. Adjusting throttle body set screw ( and resetting TPS (v) has no effect.
First two logs are for increasing cranking PW. Started at base TS setting, worked down.
Suggestions appreciated.
Cranks, wont start despite adding throttle. Adjusting throttle body set screw ( and resetting TPS (v) has no effect.
First two logs are for increasing cranking PW. Started at base TS setting, worked down.
Suggestions appreciated.
Last edited by 91blkvette on Sun Nov 23, 2014 3:47 pm, edited 1 time in total.
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Re: 427 SBC No ignition and crank signal inverted?
Datalog attempt to decrese fuel...
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Re: 427 SBC Back to not starting. Changing PWs no effect..
Have you checked ignition timing again recently, while cranking? Are you using a simple light, or a "dial-back" type? I would try disabling the fuel (pull fuses/relays for both pump and injectors, let the cylinders and plugs "air out" to dry, then try starting with a quick blast of starting fluid (fuel still disabled). That will easily tell you if the problem is fuel or something else; almost cuts your search in half.
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Re: 427 SBC Back to not starting. Changing PWs no effect..
Yep...checked crank timing..coming in at 12..set the dist at 10. Using a dial back that's set at 0. Pretty sure it's fuel related. I have a fuel pressure gauge, and it's reading a steady 40psi at turn on and crank. Got spark at the plug..In fact I cleaned all the plugs last nite..and after 1hr of testing today..one of em is dark again. And that's just on cranking alone.billr wrote:Have you checked ignition timing again recently, while cranking? Are you using a simple light, or a "dial-back" type? I would try disabling the fuel (pull fuses/relays for both pump and injectors, let the cylinders and plugs "air out" to dry, then try starting with a quick blast of starting fluid (fuel still disabled). That will easily tell you if the problem is fuel or something else; almost cuts your search in half.