Slow starting (i.e., long cranking)

[Jack Black]

My '87 GN has always fired up almost instantly after turning the key, even after being stored for the winter.

However, I now need to hold the key and crank it for several seconds. This occurs on all starts, cold, hot, etc.

On the road, it runs just fine, winds out to the shift points at full throttle with no sign of misfiring, so it's hard to believe that the plugs need changing. The only difference is in starting.

Anybody have any ideas?

Thanks

Jack

 

[kgouldsk]

When you first turn on the key, do you notice that the fuel pump seems to run particularly long to come up to pressure? Could be involved. I'm not sure how that pressure is maintained when the pump isn't running, or if it is at all, but there could be a leak in some kind of check valve, perhaps in the pump itself?

Try ensuring you've waited until you hear the fuel pump quit running after you turn on the key. Then spark it and see if it starts immediately.

 

[williamsGN]

Might want to post in the general tech section, not the TB.com Nationals forum.

 

[Jack Black]

Thanks to both of you.

 

[williamsGN]

Check fuel as above, if it has over 15k on the plugs, switch em. Pull the plugs and see how they look. Let us know

 

[we4Mateo]

Maybe the cam sensor is getting a little loose or maybe the cap is loose? This effects start timing too I believe. Or the oil pressure switch but I don't believe it takes a lot of pressure to set that sensor off.

 

[chopped39]

Install a fuel pressure gauge and watch pressure while cranking. The fuel is probably draining back into tank. A bad check valve in pump will cause this. Does the car run rough for a few seconds when first started. If so an injector could be leaking down. What kind of pump do you have in car?

 

[Jack Black]

Original pump. No rough running.

"Maybe the cam sensor is getting a little loose or maybe the cap is loose?"

I don't understand what that means. Where are they located?

(I have a complete original service manual, but it has hundreds of pages (a carton plus), and I don't have the time to dig through it all right now (in the early stages of planning a move, purchasing another home, etc.)).

I was hoping I could get some tips to pin it down and correct it quickly. The next time I take it out, I'll listen for the fuel pump prior to cranking.

Thanks

P.S. - If I need to take it in for service, are GM dealers still generally competent to work on these things (if not, we are S.O.L.!)?

 

[williamsGN]

Cam sensor has a round black top that is on top of the timing cover, next to the alternator and fuel line. It shouldn't move if you try to turn it.

http://www.google.com/imgres?imgurl...ndsp=18&ved=1t:429,r:12,s:71&biw=1280&bih=619

No I wouldn't take it to a dealership, post up your location, also post in the forums below under 'region' for where your located and ask for a good tuner in your area.

 

[hesermon]

No I wouldn't take it to a dealership, post up your location, also post in the forums below under 'region' for where your located and ask for a good tuner in your area.

x100 Do NOT take to a GM dealer! I stopped in the local GM dealer (actually a Pontiac dealer at the time) wanting to order a center cap for my TTA. A "tech" with about 6 ASE patches asked me if my car was a 301 turbo, I told him no a 301 turbo was a 1980 not an 89. When I told him it was V6 turbo he said, and I quote "Pontiac never made a V6 Trans AM, it must be a regular Firebird with Trans Am stickers"

Anyway, if you're still running the original fuel pump I would suspect leak down back into the tank. I had exactly the same problem with my GN. Try just turning the key to the on position for about 5 seconds then cranking. If it starts right up you've found your problem. I replaced my pump and now she starts as soon as I hit the key. Even if the new pump don't cure your problem you need to get the original pump out of there anyway, upgrade and add hotwire. Easy to do and a must have for these cars.