You mean an arcing spark plug wire ?
Try to check the 2 injectors while cranking .
Thanks ,
Try to check the 2 injectors while cranking .
Thanks ,
1991 Caprice 5.0l hard starting in the AM
- Thread starter WyrTwister
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Take a wire off a plug and stick a screw driver in the end of the wire and hold the metal part of the screw driver somewhere near a grounded area with a slight gap and see if you see arcing.
(Don't hold the metal part of the screw driver with your fingers, hold the plastic handle or you will get zapped if there is spark there. - gotta mention in case someone else reads this)
As for the injector pulsing you will have to look in the Throttle body to see if the injector is dispensing fuel on the Throttle Plate during cold cranking.
Both the spark and injector timing should be run off the ignition module information provided to the ECM in these early model GM's. It's possible when the module is cold it isn't working properly but when the engine is semi-warm - hot it functions properly given that your fuel priming didn't work to prove it's not fuel pressure leaking down. (Short of checking this with a fuel pressure gauge).
Good luck, and Merry Christmas / Happy Holidays!
(Don't hold the metal part of the screw driver with your fingers, hold the plastic handle or you will get zapped if there is spark there. - gotta mention in case someone else reads this)
As for the injector pulsing you will have to look in the Throttle body to see if the injector is dispensing fuel on the Throttle Plate during cold cranking.
Both the spark and injector timing should be run off the ignition module information provided to the ECM in these early model GM's. It's possible when the module is cold it isn't working properly but when the engine is semi-warm - hot it functions properly given that your fuel priming didn't work to prove it's not fuel pressure leaking down. (Short of checking this with a fuel pressure gauge).
Good luck, and Merry Christmas / Happy Holidays!
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How did you make out?
Charged the battery the rest of the afternoon , over night until noon the next day .. Battery was hot & easily spun the engine over , but did not start . Next day , I filled up a gas can and added gas to the Caprice . Cycled the key a few times and it started on about the 3rd try . Let it idle until it came up to temperature .
Started it on about the 2nd try , today , after cycling the key . Let it warm up again & then shut it down .
Started it on about the 2nd try , today , after cycling the key . Let it warm up again & then shut it down .
Originally Posted by WyrTwister
This was Mom & Dad's car , that I inherited . Rarely driven , ~ 46,000 miles on it .
I have replaced the fuel pump when it went out . And fuel filter .
Takes a lot of cranking when cold , in the AM . Runs fine after that & for the rest of the day .
I replaced the fuel pressure regulator & that did not help .
Ideas , please ?
Thanks ,
I had same problem with a Buick. Fuel pressure was low due to weak fuel pump, around 30psi when it should have been around 48 psi. BTW- the fuel pressure regulator keeps the pressure from going too high.
This was Mom & Dad's car , that I inherited . Rarely driven , ~ 46,000 miles on it .
I have replaced the fuel pump when it went out . And fuel filter .
Takes a lot of cranking when cold , in the AM . Runs fine after that & for the rest of the day .
I replaced the fuel pressure regulator & that did not help .
Ideas , please ?
Thanks ,
I had same problem with a Buick. Fuel pressure was low due to weak fuel pump, around 30psi when it should have been around 48 psi. BTW- the fuel pressure regulator keeps the pressure from going too high.
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Trying to come up with a user friendly way to check fuel pressure on this hard piped TBFI car ?
You need to get an adapter to mate up a gauge. I too am in the market for a decent gauge and you need to find one that had the proper TBI set up. Some have a rubber segment that you bypass the filter with but the one I had seen (cant remember exact make/model) but has the T fitting that attaches right at the TBI unit on the hard line. Seems much more user friendly.
FWIW I had a coolant temp sensor go bad in an old OBD-1 GM truck I had and caused the hard starting in the morning.
Originally Posted by BrianF
You need to get an adapter to mate up a gauge. I too am in the market for a decent gauge and you need to find one that had the proper TBI set up. Some have a rubber segment that you bypass the filter with but the one I had seen (cant remember exact make/model) but has the T fitting that attaches right at the TBI unit on the hard line. Seems much more user friendly.
Using an Adapter at the Throttle Body only works on some models, Or should I say.....It's only user friendly on certain models.
Some TBI engines have braided flex lines all the way up to the TB, Some have hard lines from the Bellhousing mounted fuel line hold down. Trying to use an adapter on a Hard Line model will leave you very frustrated!
You need to get an adapter to mate up a gauge. I too am in the market for a decent gauge and you need to find one that had the proper TBI set up. Some have a rubber segment that you bypass the filter with but the one I had seen (cant remember exact make/model) but has the T fitting that attaches right at the TBI unit on the hard line. Seems much more user friendly.
Using an Adapter at the Throttle Body only works on some models, Or should I say.....It's only user friendly on certain models.
Some TBI engines have braided flex lines all the way up to the TB, Some have hard lines from the Bellhousing mounted fuel line hold down. Trying to use an adapter on a Hard Line model will leave you very frustrated!
It has a hard line that connects to the TB .
I was thinking of modifying an old fuel filter to provide a place to connect the pressure gauge ?
Best I remember , the filter is mounted on the underneath passenger side of the car , forward of the RR wheel . With that side jacked up , not that difficult to get to .
Since fluids / liquids are mostly in-compressible , I would think the pressure reading would be the same as at the inlet to the TB ?
I could drop the tank again and change out the fuel pump / sending unit . Last time I replaced just the pump . The gas gauge is wonky . I would replace the complete assembly .
Happy New Year
I was thinking of modifying an old fuel filter to provide a place to connect the pressure gauge ?
Best I remember , the filter is mounted on the underneath passenger side of the car , forward of the RR wheel . With that side jacked up , not that difficult to get to .
Since fluids / liquids are mostly in-compressible , I would think the pressure reading would be the same as at the inlet to the TB ?
I could drop the tank again and change out the fuel pump / sending unit . Last time I replaced just the pump . The gas gauge is wonky . I would replace the complete assembly .
Happy New Year
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