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Discussion Starter · #1 ·
Hello everyone,

My dad and I are just about finished restoring his GN and came up with a problem. The car won't start. If I throw a little gas through the throttle it'll star right up and idle. I've taking it around the block and runs well. It just won't start without the gas splash. A local mechanic told us that it might be the MAP sensor, I cannot find it. Any pics of the location and the MAP sensor part No. is appreciated as well as any input you guys have. Thanks:cool:
 

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take some time and visit Turbo Regal Web Site when you buy a GN you want to read that site from start to finish first.
 

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GN Old Timer
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Apparently your mechanic works on Chevys. The MAP sensor has nothing to do with starting your GN. Here's the sequence:
1- Ignition tells the ecm to start the engine.
2- Ecm energizes the fuel pump (through the f/p relay) for 2 seconds.
3- Ecm watches the camshaft and crankshaft sensor signals and if sees both, fires the injectors.
4- The spark advance during cranking is fixed at 10 degrees BTDC.
5- Above 400 rpm, the ecm considers the engine "started".

So, based on what you said it appears that Step 2 is not happening. Your job Mr. Phelps (should you accept this mission) is to figure out why. This is not an impossible mission.
 

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Discussion Starter · #4 ·
Thanks for the replies. I read the content but still a little stumped. Also when I put the key in the on position I can see the fuel pressure rise on the gage. But it still seems that it is not injecting. :confused:
 

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OK! Who Farted Again??
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Another site that is user friendly & full of great info Vortex Buicks
 

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Thanks for the replies. I read the content but still a little stumped. Also when I put the key in the on position I can see the fuel pressure rise on the gage. But it still seems that it is not injecting. :confused:
You say the fuel pressure rises when you turn the key on? What does it rise to? The fuel press should stay after the engine is shut off. If your gas is draining back to the tank every time you shut the car off that would give you a hard start condition.

What happens of you lay on the starter? You can crank the engine for 30 seconds without hurting the starter, try it and see if the engine starts after a long crank... Just don't crank for more than 30 seconds and let the starter cool down for 60 seconds before trying it again.
 
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