1999 GMC Suburban diagnosis help

I have a 1999 GMC Suburban that for the last 6 months or so would not run until the second start attempt. On the first attempt, it would sputter and die. On the second try it would catch and run just fine. After the season changed and it got colder outside it would start on the first try in te morning, but require a “second start” later through the day. The catalytic converter exhibits a rattle but there is also a really rich smell of fuel wile running. Today it would not start. Whats the deal?

Sounds like the fuel pressure regulator might be leaking. Pull the vacuum line off it while running and look for raw fuel being sucked in. If the regulator is on the fuel rail. Other wise it’s under the intake plenum.

I was told it could be that or a bad filter. Thanks for the info! It wont start now, but as soon as I can get it started I will check it out. Thanx again!

Try starting with the accelerator pressed 1/2 way. If that greatly improves starting clean the throttle and idle air control.

What about the crankshaft position sensor? Could that be doing it?

What about the crankshaft position sensor? Could that be doing it?

If it were the crankshaft position sensor, the Check Engine light (CEL) would be on.

I forgot to mention it, but it is.

Did you ever get the codes read? First step to determining why a car is acting up and the CEL is on is GET THE CODES READ. Then, we can discuss what to do. Don’t go throwing parts at the problem blindly.

You can get the codes read for free at many chain auto parts stores. They have a code reader that you can borrow. You give them a credit card as collateral and they return i when you bring the code reader back into the store. Then they read the codes off the scanner for you. Call ahead to make sure that store has one and that it is working.

Sounds good. I took advantage of a free diag service from my local auto parts store just under a year ago. The computer came up with 5 or 6 different codes relating to o2 sensors, cylinder misfire, catalytic converter and a couple of others I cant remember. I lost the paperwork also. I do appreciate the info. I will have a diagnostic done and keep the community posted on what transpires. Thanks!

A fuel pressure regulator problem as mentioned could be the cause of those codes you refer to but after a year it’s also possible that a comparatively minor problem may have snowballed into a bigger one; or plural of the word problem.

It could also be a problem with the fuel pressure sensor. This is designed to maintain fuel pressure while the vehicle is not being used. If there’s a problem with the sensor the vehicle may not start at all or the start may be rough due to the fuel pressure bleeding off. It may then smooth out as the air is burped out of the fuel lines.

That sounds familiar. Is there a way to check that without the vehicle running?

Is there a way to check what? If you mean the emptied out gas lines idea turn the key to run (where the dash lights up) and back off about 10 times without cranking it over. Then crank it.

Go get the codes read. Post the exact and specific codes as “Pxxxx” - post all codes. There’s no point in continuing this discussion without the codes.