99 le sabre hot no start

[rachet16]

I have a 99 lesabre cold start rough idle but smoothes out . Warm no start. Trouble codes P0171, P0300, P0336. Had plennum replaced 2 years ago but I'm seein coolant around the base of the plennum so I'm going to have to do that again but I don't think that has anything to do with the warm no start. Any input will be greatly appreciated!;

[maxwedge]

336 points to a crank sensor or wiring issue, 171 is bank one lean, focus on 336 first as this can cause hot no start.

[Tech II]

Also check vac line to f/p regulator, for fuel....

Have all codes cleared and see which one comes back....

[rachet16]

I replaced the crank sensor yesterday. First start it ran rough and stalled. Restarted and it ran ok let it idle for a bit drove it around the block( I live in the country ) shut it off and it restarted. Today the wife drove it to town about 8 miles shut it off at krogers and she just called!! Again No Start!! No trouble codes were present and check engine light was off yesterday . I haven't checked today ! Could the problem be the ICM or cam position sensor???

[maxwedge]

When it won't start you need to check spark first.

[rachet16]

Just got the car home it finally started after about 2 hours. Check engine light back on P0404 and P0171 ??? Lean bank one and egr???

[Tech II]

I believe you need a crank variation relearn, when you replace the crank sensor.....need Tech II for that....

But like Max says, when it won't start, check for spark, fuel pressure, and injector pulse......also try disconnecting the MAF to see if it will start....did you check that vac line for fuel?

[rachet16]

Car won't start! Checked for spark at each coil terminal I have spark there. No fuel in regulator vac line.

[rachet16]

Tech11 for relearn??? I don't know what that means. I did disconnect the maf still no start.

[rachet16]

There is fuel getting to the regulator at the check valve.

[maxwedge]

Will it start if you spray carb cleaner into the intake, if so you may have 1 shorted injector, which can pull down the other injectors and no start.

[Tech II]

When ever you replace a crank sensor or PCM, there is a "crank variation relearn" procedure that has to be done....only special scan tools like a Tech II can do this.....it basically prevents improper misfire readings....

However, should not cause a no start.....the fact you have spark, means you are getting a signal from the crank sensor.....

As Max suggested, have someone crank the vehicle, while you spray carb cleaner into the intake....if it starts and runs as long as you spray, then it's a fuel problem...either the injectors, or a fuel pump....next check fuel pressure at the rail....if you have good pressure over 40psi, then there is either an injector, injector circuit, or PCM problem(could also be an ICM problem if the ICM is not sending a reference signal to the PCM)......see if the injectors are pulsing with a noid light.....

[rachet16]

Worked on the Buick changed plennum plugs , plug wires, r&r icm cleaned and greased base (it was corroded and dry) tested injectors( ohm meter). The car starts cold if I run it and turn it off it will immediately restart but if it sits 10-15 min. it will not restart. It fires but chugs and sputters and dies! Then no start. I borrowed/ rented a fuel pressure gauge from autozone today. When I turn the key on no pressure, if I start the car it's at 25 psi turn the car off and it goes up to 28psi.. I pulled the fuel filter it was clear no restrictions. I don't know why there is no pressure when I turn the key??? The car starts and drives when cold.

[rachet16]

I also noticed today that if I cruse at 55 and floor it there is literally no response!!
I'm thinking fuel pump or the gauge was junk!

[rachet16]

I should also note P0171 and P0404 trouble codes have returned.