Oldsmobile/Buick Repair: Olds 98 1987 hard starting, resistor pack, coolant temp

Question
Van See my reply below to your questions.

Old 98 1987 hard starting
Question   I am having difficulty with my 1987 Old 98 Regency V6 3.8 L.

The car runs like a champ once started. The issue is to get it started once the car has stat for the night and worse when really cold.

Here it what happens. It fires like its going to start but doesn't. In order to get it going 9 out10 times I need to pump the gas pedal and hold it.This is even worst when the car is cold (I live in the northeast so we have cold weather and the car sleeps outside)

I can hear the gas pump run when the key is first turned.

I also have a service engine soon light that comes on when driving down the road, sporadic and turns off and I do not know if the 2 symtoms are inter-related.

I usually do most of my car repairs but, I have no clue where to start with this one and the weather was too cold(-25) for me to work on it outside, so I sent it to the local shop. I went to pick-it up friday and they said they could not find anything wrong.

So now I'm back at square one and still looking what could be causing this. Could this be caused by an oil pressure, gas pressure, gas return, a relay, ignition module...

I've check the fuel pressure yesterday at the rail 43lbs with no regulator and 30 lbs with regulator at idle.If I rev the engine the pressure drops to 28lbs steady.

Could this be the coolant temp sensor, crank sensor or the fuel pump.

One more question conserning the heater fan. The fan works and does not work (Sporadic). When it works all speeds work fine so I presume the resistor pack is OK, after it starts usually comes on after 5 minutes of driving(a bump seems to help start-it)once on it has never stopped. If I turn the ignition off for a few minutes it does not 9-10 times come back on we do not touch anything on the heater control.What could this be cause by fuse, relay, bad connection, blower motor?

Any help or clue with resolving these two problems would be greatly appreciated.

Thanks,

Marc,

Answer   Hello Marc,
First, I need to know if it is throttle body injection, which looks like a carb, but has two injectors in the throat, or MPFI, which has an injector in each intake manifold runner.
The pressure is different for each.
The throttle body injection should have about 14 PSI.
But if you have the other kind, I think your pressure is dropping too much. That could be from a stopped up fuel filter.
Any chance you have water in the gas tank?

I think your fan motor may be about worn out, but I would sure connect a test light to the wire right at the blower motor to see if power is still there when the blower doesn't work.
A bad ground wire, or loose motor screws could also be the problem. But I suspect the motor brushes. Can you hit it and make it work?

Van

Thanks Van for the Info on the heater will do.

As for  if it is if it is throttle body injection, which looks like a carb, but has two injectors in the throat, or MPFI, which has an injector in each intake manifold runner.
- The car is MPFI - 1 injector per cylinder and the all work with new O-rings checked and tested they work.

That could be from a stopped up fuel filter. New 2 weeks old started by replacing this and flushed the gas tank. put all new gas with 2 cans of dry gas so far.

So I guess am I down to the pump? Any chance this could be cause by the temp sensor or the crank sensor. The car also has a hard time Ideling down as well when warm.

Again, thanks for all input. Car is in super shape and would like to keep it going as long as I can.

Marc,  

Answer
Hello Marc,
I really doubt it is the fuel pump, and I really doubt it is the crank sensor, since the fuel pump is running.
The temp sensor??/ Could be. If it is sending a signal telling the ECM it is at operating temperature, it sure seems like it could be trying to start with the wrong fuel mix. I'm not sure on that, but seems possible.

Van