Maybe someone could help me understand my issue. My car ('94 Z28) has been starting very hard. It takes a few cranks to finally get it to turn over. But when it does, it idles very rough and just sputters around. If I tap the acc. pedal to rev up the engine, the car shuts off. The other thing is that I smell lots of gas fumes from the car. It also seems like the more the cars sits i the driveway the harder it gets for it to start. Anyone have any idea what could be wrong?

I appreciate your thoughts,

Thanks.

 

first thing i would check would be the coolant temp sensor.

 

check your fuel pressure using a fuel pressure guage. make sure you use alot of rags b/c u'll leak some fuel when you attach the guage. just prime the pump and turn the car back off, let it sit and watch the fuel pressure guage and see if it drops and by how much. as for the fuel smell, is it inside the car? the front or the rear? if its coming thru the vents you can try to check your fuel pressure regulator for a leak with a vacuum guage. or maybe you have a leaky fuel injector or 2. hope you figure it out.

 

I smell the fuel sitting sitting in my car with the door open... but i beleive it is coming from the back.. maybe the front.. but definetly not form the a/c vents. I had the fuel pump replaced like 9 months ago. Sometimes, i've also noticed, is that when i want to start the car, it won't completely start... it would sound like it was "coughing".... but then i'd leave the car alone for a coiuple of hours and it would start again like nothing was wrong with it. You think it would indicate something different?

 

sounds like your engine is getting flooded with gas. a faulty CTS sensor is one cause of this.

 

"I smell the fuel sitting sitting in my car with the door open... but i beleive it is coming from the back" - Might want to check the fuel filter first, it's an easy $10 since you said the pump was replaced. If it's blocked it will sputter to try to get fuel through, your best bet is to check the pressure to see if it's high / low to help determine the direction you need to go. If it's low it's either the fuel pump not able to deliver or the filter blocking. The only other item is the regulator...just my 0.02

 

Just curious, what would the coolant temp sensor have to do with the fuel delivery on start-up?

 

It has everything to do with start-up. the colder the sensor reads, the more fuel it will dump in the cylinders.

A unplugged CTS sensor will automatically read -40 degrees F.
that floods an engine like butter.
While cranking your engine, the injectors are almost wide open, and just keep opening more and more until the pcm detects 400+ RPM (start-up)
If he's smelling gas while cranking over the car.......it sounds to me like hes getting plenty of fuel.....and the cylinders are getting filled up with it. When an engine is flooded, it will be VERY hard to kick on. you have to leave your car alone, and the gas will empty by seeping through the cylinder rings and then you will have a better chance of cranking.

To see if your car is getting flooded while cranking, you could use the "clear flood" start-up. Clear flood is initialized by having the TPS over 2.50 volts while cranking. this will kill all the injectors.

Try cranking the car up for 3 or 4 seconds, then slam the throttle to the floor. See if it kicks over better. let the pedal back up to add fuel, and press it all the way down to kill fuel. give it a shot.