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BryanB
Joined: 21 Mar 2022
Posts: 4
Location: Las Vegas, NV
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 Posted: Thu Mar 24, 2022 12:28 am Post subject: 1979 Porsche 924 crank/ no start |
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Hello, my name is Bryan. I have been looking at all the forums that relate to my concern but i still can’t seem to figure it out. I’ve only ever worked on Japanese vehicles so it took me a bit to understand how the 924 works. I’d appreciate anyone who takes the time to help. Sorry for the long post, just wanted to explain in detail.
I verified fuel pump operation directly and when it receives voltage when cranking. Replaced the fuel pump relay just to remove doubt. It might be me doing something wrong but sometimes it won’t power when cranking.
I verified three of the injectors are spraying a nice mist. One not firing at all, but i’d assume it would still start with three injectors?
I’ve also verified spark at the plug when grounded, i have no other way to test the plug.
Also firing order was incorrect but i fixed that, 1342, clockwise on distributer but no avail. Checked distributer rotor was on cylinder 1 when i timed the crank pulley to the notch, but not tdc, i hope it is. Ignition coil primary was 1.7 ohms which is slightly out of spec, is that enough to cause no start? Secondary was at about 8.3kohms which is also slightly out of spec. We got a new coil that supposedly worked with the 924, of course its autozone 🤷♂️.
The specs are no where close to what they should be but still has spark when i tested it.
So i have fuel and spark. Car was running beautifully before so i haven’t checked compression, and my friend said that there was an engine noise when running that came up after driving through a drainage dip at slow speed, didn’t bottom up. Told him to change oil and check for any metal but he didn’t find any. New oil and was still tapping, i never got to hear the noise in person but then slowly the car would take longer to start until it didn’t start again. Car cranks good, sounds healthy but maybe a little slow, we make sure to have a charged battery. I’ve also tried starting it with starter fluid but that doesn’t want to do anything. I’m not sure if that would start a Porsche, European cars seem difficult to me. And this is where i would like to ask for opinions on things. Whether i should confirm again or maybe something i’ve been missing. This is a friends car that i really want to help get running. Any help is appreciated and i hope you enjoy your day.
Last edited by BryanB on Thu Mar 24, 2022 12:37 am; edited 2 times in total |
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kondzi
Joined: 02 Jul 2018
Posts: 494
Location: Poland/EU
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| Posted: Thu Mar 24, 2022 12:33 am Post subject: |
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Does it have an attitude that is willing to start or there is nothing at all?
No start means no fuel or no spark or both.
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Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded) |
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BryanB
Joined: 21 Mar 2022
Posts: 4
Location: Las Vegas, NV
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| Posted: Thu Mar 24, 2022 12:41 am Post subject: |
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| kondzi wrote: | Does it have an attitude that is willing to start or there is nothing at all?
No start means no fuel or no spark or both. |
Honestly no, doesn’t even want to sputter which is worrying. But i know i have spark and fuel, spark plugs will come out drenched in gas after a couple tries which leads me to believe spark is an issue. whether its at the proper time i’m not sure, can i check with a timing light while cranking? I updated the post, forgot to mention the mechanical portion. |
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kondzi
Joined: 02 Jul 2018
Posts: 494
Location: Poland/EU
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| Posted: Thu Mar 24, 2022 1:29 am Post subject: |
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| BryanB wrote: | | kondzi wrote: | Does it have an attitude that is willing to start or there is nothing at all?
No start means no fuel or no spark or both. |
Honestly no, doesn’t even want to sputter which is worrying. But i know i have spark and fuel, spark plugs will come out drenched in gas after a couple tries which leads me to believe spark is an issue. whether its at the proper time i’m not sure, can i check with a timing light while cranking? I updated the post, forgot to mention the mechanical portion. |
Spark could be weak and too much fuel can drown the spark plugs.
Do you have access to a fuel pressure gauge to check the pressures in the CIS system? Have you ever worked on a car with K-Jet/CIS?
_________________
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Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded) |
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ChrisMadge
Joined: 16 Dec 2020
Posts: 29
Location: Bristol, UK
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| Posted: Thu Mar 24, 2022 2:38 am Post subject: |
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| Quote: | | Checked distributer rotor was on cylinder 1 when i timed the crank pulley to the notch, but not tdc, |
Not sure what you are trying to say there. Are you sure the static timing is correct ?
Notch on main crank shaft pulley needs to align with the mark on the engine AND the cam shaft dot on the back of the gear wheel align with the mark on the cam shaft cover. Number 1 spark plug (nearest to radiator) should be firing before/after (depending on engine spec) this point.
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1984 MY 924 2.0 NA
1975 MG Midget |
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BryanB
Joined: 21 Mar 2022
Posts: 4
Location: Las Vegas, NV
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| Posted: Thu Mar 24, 2022 3:28 am Post subject: |
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| kondzi wrote: | | BryanB wrote: | | kondzi wrote: | Does it have an attitude that is willing to start or there is nothing at all?
No start means no fuel or no spark or both. |
Honestly no, doesn’t even want to sputter which is worrying. But i know i have spark and fuel, spark plugs will come out drenched in gas after a couple tries which leads me to believe spark is an issue. whether its at the proper time i’m not sure, can i check with a timing light while cranking? I updated the post, forgot to mention the mechanical portion. |
Spark could be weak and too much fuel can drown the spark plugs.
Do you have access to a fuel pressure gauge to check the pressures in the CIS system? Have you ever worked on a car with K-Jet/CIS? |
I thought the spark could be weak hence why we got another ignition coil but i have no way to test the strength of the spark. I’ll have to find a fuel pressure gauge for this system. This is my first time working on a porsche. |
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BryanB
Joined: 21 Mar 2022
Posts: 4
Location: Las Vegas, NV
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| Posted: Thu Mar 24, 2022 3:33 am Post subject: |
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| ChrisMadge wrote: | | Quote: | | Checked distributer rotor was on cylinder 1 when i timed the crank pulley to the notch, but not tdc, |
Not sure what you are trying to say there. Are you sure the static timing is correct ?
Notch on main crank shaft pulley needs to align with the mark on the engine AND the cam shaft dot on the back of the gear wheel align with the mark on the cam shaft cover. Number 1 spark plug (nearest to radiator) should be firing before/after (depending on engine spec) this point. |
When i lined up the crank pulley to the mark the distributer rotor was pointing at the number 1 spark plug. I never knew about the camshaft marking but everything else was timed and i didn’t check if cylinder one was at TDC. i’ll have to check and make sure. |
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