Lately, I have had problems trying to start my car. Very intermittent. Maybe 1 out every 50-100 starts. I would have to crank it for a while(20secs?) before it starts. Yesterday, I unplugged my fuel pump, cranked the engine to relieve fuel pressure, hooked the fuel pump back up and it started right up! Later in the day, it was hard to start so, I did the same thing. Get this, the car started without the pump hooked up! It happened when I was trying to relieve the pressure. Quickly, I hooked it back up and it continued to run.

 

Otherwise the car runs great. The fuel pump sounds good. It starts right up the other 99 times.

 

??What would be causing this?? I am stumped.

 

Is it too much fuel/pressure? Flooded? Injectors? Regulator?

I haven't kept track but possibly after it rains/High humidity??

I have also had success revving the engine when I turn it off to ensure a good start.

 

95-Subaru Legacy Wagon-2.2L Auto

230,000+miles

New fuel filter. New Air Filter.

 

Thanks Guys.

Lately, I have had problems trying to start my car. Very intermittent. Maybe 1 out every 50-100 starts. I would have to crank it for a while(20secs?) before it starts. Yesterday, I unplugged my fuel pump, cranked the engine to relieve fuel pressure, hooked the fuel pump back up and it started right up! Later in the day, it was hard to start so, I did the same thing. Get this, the car started without the pump hooked up! It happened when I was trying to relieve the pressure. Quickly, I hooked it back up and it continued to run.

 

Otherwise the car runs great. The fuel pump sounds good. It starts right up the other 99 times.

 

??What would be causing this?? I am stumped.

 

Is it too much fuel/pressure? Flooded? Injectors? Regulator?

I haven't kept track but possibly after it rains/High humidity??

I have also had success revving the engine when I turn it off to ensure a good start.

 

95-Subaru Legacy Wagon-2.2L Auto

230,000+miles

New fuel filter. New Air Filter.

 

Thanks Guys.

 

If it is flooded, crank with the accellerator floored.

If it starts right up, it was flooded.

 

 

Dave

Its possible your crank position sensor is on its way out. This is one of those hard things to diagnose. Blu does this when the temp is between 35-42 degrees, and ONLY at those times.

 

at 245.000 miles he is allowed a quirk.

 

 

nipper

Thanks. Will check the CPS. Any other ideas guys.

You may wanna soak that puppy.

 

Sometimes they are very difficult to remove and actually break.

Possibly a failing fuel pump. A pressure gauge could help.

 

Compression/fuel/spark... which one is inadequate? Probably not compression. Do you know if you have spark when it is refusing to start? I would think that if the CPS was flaking that you wouldn't have spark when it refuses to start (might not have fuel delivery, either). An injector-signal tester ("noid") could let you tell if the injectors were being told to inject.

 

Are you getting any "Check Engine" codes?

 

Are you getting any "Check Engine" codes?

 

 

The car needs to start and run to throw a code. Its the weakness of OBD type diagnoses.

 

 

Crank PS controls spark, Cam PS controls fuel injection. Usually the crank sesnor goes out more often then the cam sensor. I would rule out any fuel issues since the car starts and runs fine otherwise.

 

Don't you just love electonics?

 

nipper

I usually find hard starts after running for a while are often Coolant Temp Sensor failures.

 

If the CTS has high resistance, ECU thinks it's a cold engine. Rich mixture fed into a warm engine = no start/hard start.

 

Test the resistance range of the sensor cold and hot. If you can, hook test leads to it, and then tap on it to make sure the resistance doesn't change or drop to zero or infinite.

Thanks again guys! Great info. The only thing that confuses me is why it started right up when I unplugged the fuel pump, relieved the pressure, plugged it back in, then it started right up. ????

Bad fuel pressure regulator?

 

 

nipper

That is what I am leaning toward. Leaky injector- 2nd. So how do I test the FPR? Is it a vacuum test or is there an easier way?

It ends up it was a fuel pump with a dead spot. That is why I was getting intermittent hard starts. I check every sensor and they all were fine. I pulled the pump and applied power to the red and black. It ran fine. Took it back to the car and hooked it to the harness. Did not run. Took it back inside and it did not run. Smacked it with a wrench while applying power, STARTING RUNNING. Back to the car, harnessed, smack, RUN. I think you get the point. Replaced it with a new pump and screen filter($112) and everything runs well. Yeah!

 

Good job NorthWet, you called it.

Don't worry guys, I know you all thought of it too. hehe

 

 

Maybe relieving the fuel pressure helped the ailing pump start better???

I am glad to know all my other sensors are fine. Well, I did find a stuck PCV valve. $5

Edited July 17, 200916 yr by JimmyJam
Added line

Ok, I am sure it is fixed now. The gremlin came back a few days after I installed the new pump. (Hard start after running it all day) Well, I finally got a check engine light and had it checked at Autozone. Code was for faulty crank position sensor. Got one there for $25 and looking good so far. What are the chances...a failing fuel pump and bad crank sensor at the same time.

Ok, I am sure it is fixed now. The gremlin came back a few days after I installed the new pump. (Hard start after running it all day) Well, I finally got a check engine light and had it checked at Autozone. Code was for faulty crank position sensor. Got one there for $25 and looking good so far. What are the chances...a failing fuel pump and bad crank sensor at the same time.

 

Ain't that just the way it always is.

 

Dave