964 engine rebuilt but no start
05-12-2018, 09:41 AM
#1
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964 engine rebuilt but no start
Hi
My engine has been completely rebuilt but won't start. Mechanic said they checked the timing, vacuum, and everything else. Its been like this for a couple of months. Video below. Anyone have any ideas? We are stuck.
My engine has been completely rebuilt but won't start. Mechanic said they checked the timing, vacuum, and everything else. Its been like this for a couple of months. Video below. Anyone have any ideas? We are stuck.
05-12-2018, 12:09 PM
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05-12-2018, 12:11 PM
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Maybe this will help http://www.ifitjams.com/starting.htm
Any other ideas?
05-12-2018, 12:16 PM
#6
Looks to be getting spark and fuel - comes down to how it's getting them. Did they spray some kind of starting fluid to get that far? If they don't do that, does it just crank? You have the distributor (suspect) and the EFI itself. Not much help, I know - but that's where I'd start.
05-12-2018, 12:34 PM
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Looks to be getting spark and fuel - comes down to how it's getting them. Did they spray some kind of starting fluid to get that far? If they don't do that, does it just crank? You have the distributor (suspect) and the EFI itself. Not much help, I know - but that's where I'd start.
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05-12-2018, 03:46 PM
#8
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It’s hard to diagnose an issue over the Internet but I have spent enough time on here to know that many of these types of issues are simple fixes.
Your engine looks like it wants to start but is missing one or possibly a couple of vital ingredients. Assuming you have fuel pressure it will be spark.
I would start with the items the DME needs to work:
1. Is the car in idle mode i.e. the idle microswitch is on?
2. Is the crank reference sensor working and connected properly?
Check that they haven’t mixed up the crank sensor and knock sensor plugs. On the image they are the Black and Green plugs and can be interchanged. The Black plug is the crank sensor and the Green one is the knock sensor. The DME is not going to fire the ignition if it doesn’t know what position the crank is in. A knock sensor isn’t going to tell it anything. Hope it’s that simple.
05-12-2018, 06:02 PM
#9
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Engines need fuel air and spark. Debug those one at a time and report back on findings of each.
05-14-2018, 02:34 PM
#10
Three Wheelin'
If it was a rebuild done by an inexperienced 964 mechanic, or one that is sloppy, it could be something like incorrectly connected ignition and plug wires, cam timing not set correctly, distributor not properly installed (for example crankshaft not set to cylinder 1 TDC), etc.
05-14-2018, 04:24 PM
#11
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Let's not be too critical, here is a list of obvious stuff I have screwed up over the years:
Ck all pins in the hall sensor connector to distributor, have pushed them out by accident so one of the three isn't making contact.
Ck that you didn't install the distributor 180 degrees out, small tabs on distributor housing aligned when #1 at tdc
Did you replace the flywheel during the rebuild? Ck reference sensor and 60-2 flywheel teeth. Ran into an aftermarket setup once where an aluminum flywheel had steel teeth attached and they weren't in the proper orientation
ck fuel pressure at the rail should get approx 3.5 bar, if not check orientation of fuel lines to/from tank
ck ground to coils and ignition modules on left of engine bay
PMO makes a nice 50mm carb setup
Ck all pins in the hall sensor connector to distributor, have pushed them out by accident so one of the three isn't making contact.
Ck that you didn't install the distributor 180 degrees out, small tabs on distributor housing aligned when #1 at tdc
Did you replace the flywheel during the rebuild? Ck reference sensor and 60-2 flywheel teeth. Ran into an aftermarket setup once where an aluminum flywheel had steel teeth attached and they weren't in the proper orientation
ck fuel pressure at the rail should get approx 3.5 bar, if not check orientation of fuel lines to/from tank
ck ground to coils and ignition modules on left of engine bay
PMO makes a nice 50mm carb setup
05-14-2018, 04:44 PM
#12
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I'll throw in DME relay simply because my car quit and wouldn't start and that was the culprit. Granted, this may be more complicated due to it being a new rebuild.
09-17-2018, 10:15 AM
#14
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It’s hard to diagnose an issue over the Internet but I have spent enough time on here to know that many of these types of issues are simple fixes.
Your engine looks like it wants to start but is missing one or possibly a couple of vital ingredients. Assuming you have fuel pressure it will be spark.
I would start with the items the DME needs to work:
1. Is the car in idle mode i.e. the idle microswitch is on?
2. Is the crank reference sensor working and connected properly?
Check that they haven’t mixed up the crank sensor and knock sensor plugs. On the image they are the Black and Green plugs and can be interchanged. The Black plug is the crank sensor and the Green one is the knock sensor. The DME is not going to fire the ignition if it doesn’t know what position the crank is in. A knock sensor isn’t going to tell it anything. Hope it’s that simple.