motor turns over, but won't start... sometimes

**Fueled** · 01-15-2009, 11:21 AM

My ls1 in my 98 Z28 will not start sometimes. The motor turns over, but it dosent always start on the first try. Sometimes it might start the next crank, or I might have to try a few more times. Occasionally, but more often now, I have to try 10 or more times to get it to start.

I hear the fuel pump prime each time. I've even tried letting the fuel pump prime a few times before I finally let it turn over. None of this seems to make a difference. It either starts or it doesn't. Once the car starts it runs great... no hesistation or power loss.

A friend suggested it might be my fuel pump, but I figured since it ran so great once it started that it probably wasn't the fuel pump. I figured the same for the fuel filter too.

I don't think its a security or VATS issue; I read your car won't even turn over if it is.

If anyone has some advice as to where I should start looking, I would be greatly appreciative. I hate to take it to the dealer right now since I'm almost broke right now.

Thanks,
Jon

**0rion** · 01-15-2009, 11:50 AM

check your fuel pressure at the rail and see what you have.....it does sound like a fuel pressure issue to me. Should have ~58psi at the rail.

**Fueled** · 01-15-2009, 12:05 PM

Thanks for the reply. I figured that would be the first suggestion.

I havent tinkered much with this LS1. Does the stock LS1 have a provision to attach a fuel pressure guage? I have one attached to my older L98 Camaro and was thinking about taking that one off.

Thanks again.

**346ci** · 01-15-2009, 12:15 PM

There is a schrader valve on the fuel rail to make checking fuel pressure a breeze

**0rion** · 01-15-2009, 01:51 PM

Originally Posted by 346ci

There is a schrader valve on the fuel rail to make checking fuel pressure a breeze

there's a cap on the end of the drivers side rail...just unscrew the cap and the valve is there.

**joess567** · 01-19-2009, 09:09 AM

i had a similar problem on my 99 ls1... dealership chased ALL KINDS of problems... no codes were being set... they blamed the VATS and the fuel pump and the computer. finally a different dealership found it when the mechanic monitored MANY of the control signals... the final part that fixed it:
CAM POSITION SENSOR (its only needed at startup, the crank position sensor provides all the data for the ignition once the car is running). the signal SHOULD be present at all times, even though the computer does not use it after its running, but the mechanic saw that it was dropping out