Help Please!

[Cmo5]

I recently purchased an 87' Grand National that has a lot of miles on it (150,000+). The car starts right up and drives fine and once it's been turned off, it cranks but doesn't start. I have to jump start it to get it going again. It cranks fine but doesn't start without a jump. The seller told me this was normal for the car because it sat a lot. Any suggestions please!! Thank you!!

 

[Daniel PErkins]

My thoughts here is that any car that starts cold, then after hot--will not start means one of the big three is missing--fuel? Spark? Or last but not least--compression? If you have to jump the car--why? Is it dead and no crank? Or just cranks and no start? If it cranks excessively--what is your oil pressure? If the pressure is less than 4 psi --the fuel pump will not turn on. Do you hear the initial pump turn on when ignition is turn to "on" position? All these things can be found in service manual or diag. Trouble tree. Hope it helps. Dp

 

[VtheGNMan]

If you have less than than 10 amps in the battery it will crank but not fire. If I remember right it knows it will not have enough juice to light the spark so it goes into protection mode or something like that. The coil pack needs ample juice to lite the spark. It will crank over just fine as there is plenty of juice to turn the starter.

 

[GNVenom]

If the pressure is less than 4 psi --the fuel pump will not turn on. Dp

Nope, that is not the way it works. The oil pressure has nothing to do with the fuel pump NOT running.

And if your battery voltage drops below 9 VOLTS, the injectors won't open...low voltage cutoff plays into it at that point.

 

[Nick Micale]

Maybe at 150K miles you should be looking at mechanical issues before you get carried away with electrical problems?

If this is a stock un-opened engine, my first concern would be the timing chain, no start when hot is a good clue to me, just replaced a trashed 150K mile badly worn stock chain set.

 

[Cmo5]

I just got the vehicle yesterday and according to the previous owner, he believes the timing chain was replaced about 40,000 miles ago or so. He told me the vehicle has been doing that recently and attributes that to the vehicle sitting in the garage a lot instead of being driven. The GN started right up off the trailer and I drove 25 minutes and turned it off for about 10-15 minutes and started up and drove back 25 minutes w/o any issues. The car sat for about 30-40 minutes and then wouldn't start. It cranks fine and sounds like it wants to start and a few times it did for a few seconds but immediately stalled. The previous owner said I promise it will start if you jump it or use a jump box and then let it run for a little bit until the volts get up. I jumped it for 10-15 minutes and it did start and drove it for another 10 minutes with no drive ability issues. There is a scan master inside and the volts fluctuated between as high as 13.9 to as low as 13.2 while idling. The battery is Interstate and is supposedly not very old. I thought the same thing as stated above, cranks but no start has to be fuel or spark related but supposedly the fuel pump is relatively new also. Thank you everyone for your help, I'm wondering now if I should just try to sell the car??

 

[X Ray]

Location.....someone close may be able to help....

 

[VtheGNMan]

Sorry I meant volts. And you would have to watch the volts on the scanmaster while cranking as they will drop when under load.

 

[turbo39151]

Check the battery voltage when it's not running. Maybe it has is older than you think, maybe won't hold adquate charge.

 

[bpman1234]

Next time you get it running move that orange wire next to the battery that's the ecm wire it might be on its last string check it

 

[Nick Micale]

The next time it will not start, see if there is spark and fuel pressure when it is cranking which is easy if someone is with you to help, a little harder by yourself.

 

[GNRick]

I just went thru this with an interstate battery. Buy a battery hydrometer at Advance for $5 and check each cell. I had a bad cell. Car started right up with kirbans jumper. Did some research on batteries and bought one from Advance after testing each cell on the new battery.

 

[TexasT]

Used car, no way to know any of the info you have is good. Have the battery load tested. I'd figure in a new timing set as this info is not reliable either.
Stock injectors? Cleaned at the least, New would be better. Fuel filter new?
Cam sensor set correctly?
Fuel pump age/condition?
Hot wired?
Fuel pressure koeo? Fuel pressure with engine running?
Compression test and a leakdown? Results?
Look up spring cleaning and figure on doing it.