Major SHO problem, have no idea what it is...

[finl42]

Just wondering if any of you can help me with this SHO problem...

Symptoms: Car starts normally when cold...say I drive around, car gets warm, then I shut it off...come back out to start it, it will just crank and crank, but will not start. The only way I get the car started is by popping the hood, and hitting the fuel pressure schrader valve on the intake, causing fuel to squirt out...then the car will start normally!

Also, I am getting about 11mpg. I ran codes on the car, and came up with a 173 and 177 (O2 sensors). Problem is, I JUST replaced the O2 sensors on the dang car a couple of weeks ago!

I believe my problem IS O2's, is that what everyone else thinks? I just put in a new fuel pump also...I do have a check engine light on too, it comes on and then goes off etc.

One more question...these are Bosch O2's, from O'Reilly's...if they ARE in fact my problem, can I just go into O'Reilly's and say "these are bad"? I figure they wont' believe me...

Thanks a lot!

Joel Godfrey

 

[93EmeraldMTX]

its gotta be the 02 sensors IMO, id get under there and make sure the connections where you clip the 02s in are free from corrosion, etc.

Also, instead of cracking the schrader, try cranking with the gas pedal at WOT, it shuts off the injectors until it starts. It might save you from having to go through getting out of the car, etc.

 

[finl42]

Thank you for the input...the electrical connectors seemed clean when I replaced the O2's...

Thanks again for the info.

 

[AutoSHO]

Check your fuel pressure, sounds like it might be a similar symptom to what I had... My FPR went bad and became affected by temperature. It would run as much as 70 psi cold and as little as 20 psi hot.

It sounds like it is flooding on a hot start. I'm not sure why cracking the schraeder valve would do anything. Check the fuel pressure, I suspect it might be out of line with expectations.

 

[Rockledge]

Your SHO is running rich. Codes 173 and 177 are telling you that. So you have to find out why your motor is either getting too much fuel or not enough air.

 

[finl42]

Ok, first things first...I should check the fuel pressure...I assume I do that with the car running(pardon my stupidity, never done it before). I'll have to buy a fuel pressure gauge..

What is normal operating PSI for a SHO's fuel pressure?

If my fuel pressure IS low, what's the next step?

Thanks!

 

[PAracer]

Possibly the fuel pump if the pressure is low. Do you cycle the ignition key before you try to start the car? This would be turning the key so that the fuel pump runs and pressurizes the lines.

 

[finl42]

PAracer -

I do cycle the key...still doesn't work though. The fuel pump is brand new, as are the O2's...

I suppose I could do the fuel pump test using the paper clip?

Thanks for the input guys...

 

[HopefulSHO]

Dude, if your car is running rich, your fuel pressure probaly isn't too low - but could very well be too high. First thing I would do (since you just replaced your O2s) is find out what fuel pressure you're running at the manifold.

 

[Rockledge]

HopefulSHO:
Dude, if your car is running rich, your fuel pressure probaly isn't too low - but could very well be too high. First thing I would do (since you just replaced your O2s) is find out what fuel pressure you're running at the manifold.

I agree.

And in addition to what AutoSHO said about the fuel pressure regulator on his SHO, I recall reading another thread (or two) started by someone else who had a similar problem ...and it ended up being caused by a leaky FPR.

 

[finl42]

Another question

Where in the heck is the fuel pressure regulator?

Haha...all of the work I've ever done on all these SHO's I've owned and I don't know where it is located...or what it looks like.

Thanks

 

[masho95]

Try pushing the gas pedal all the way to the floor when trying to start the car when it won't. It'll shut the injectors off if there's already too much fuel. How does your temperature run? Does it ever rise above the L in NORMAL? If not I'd check out the thermostat..it'll cause no heat and a rich running condition.

 

[Rockledge]

finl42:
Another question

Where in the heck is the fuel pressure regulator?

Haha...all of the work I've ever done on all these SHO's I've owned and I don't know where it is located ...or what it looks like.

Thanks

Look for it on the passenger side of the fuel rail, closest to the firewall. It's kinda small, metal and cylindrical in shape (almost looks like a mini-EGR valve) and has a vacuum line coming off the top of it that leads to the intake.

There is another similar looking component (fuel pulse dampner) right behind it (i.e., toward the front of the car) which does not have a vacuum line going to it.