I have a 98 S70 T5 with 125k on it. I have recently developed a starting problem when the engine is hot. When i shut the car off and run into a store for a minute the car has a strong crank but takes 5-10 times to start. The car runs fine otherwise. Any advice would be appreciated.

 

Is it only while the engine is hot that you have the problem?

 

isn,t it what he ClEARLY Stated?
Or just want to increase your thread count.

 

On a forum this dead... seems like a waste of time.

 

Then explain what your question was about.
You made no sense.

 

Have you covered the basics:

1. State of tune? had a stage 0 lately?
2. Ck the basics:
   1. Compression
   2. Vac leaks
   3. Fuel Pressure

Would also mention spark but we can asume that since you say it runs fine otherwise. Still a dirty/old rotor and cap could cause hard starting. Have you tried opening the throttle when it doesn't start? Does that help/hurt? Any more details/background would be helpful...

 

I replaced the plugs, wires, cap and rotor, fuel filter at 100k. It seems like when if I step on the gas pedal it makes it harder to start, however if I turn the key to the on position for 5-10 seconds without cranking the engine over the car starts right up. I have read other articles suggesting that this could indicate that the fuel pump check valve is failing.

 

If the fuel is able to pass backwards through the check valve then it would make sense that leaving the key in the on position to allow the fuel pump to re-charge the line would work.
Its unlikely but you could have a fuel leak causing the problem.

Does the length of time that you leave the car off for seem to have any effect? If you shut the car off and turn it back on within 5 seconds does it fire up right away?

 

when I run the car until its hot then shut it off and try to start it right back up it does start but then stumbles and stalls out.

 

Number 3 on my list; ck the fuel pressure.

my guess is either the fuel pump relay or fuel pump itself is failing; my $$ is on the latter.

 

What makes you think that the fuel pump/relay is failing? Did he not say that if the key is left on for 5-10 seconds the car fires right up. Replacing parts just because.... that is crazy talk.

OP: If you are able to check the fuel pressure that would be a good Idea. Check in when the car is off (testing for residual pressure), test the pressure when the car is off but the key is in the on position, and test the pressure while the car is running. It may also be helpful to hook up the pressure tester while the car is off and then have someone turn the key to the on position, if it takes a while for the line to charge then it's probably a vacuum leak.

 

I have tried a different fuel pump and fuel pump relay. I have replaced the camshaft position sensor and put brand new Volvo plugs, gaped at .028. I did have an oil leak from the seal behind the cap and rotor, the seal was replaced and there is no sign of further seepage. Should I replace the cap and rotor? They were replaced at 100k in July of 2008 along with the spark plugs wires, spark plugs, fuel filter, air filter. I have a high performance fram intake filter that has also recently been cleaned. The vehicle now has 135K on it.