hard starting

I have a 1999 5.3 silverado 172k miles. recently started having problems starting when warm. It would start but took 2 or three cranks then ran rough for a few seconds. It ran fine and had lots of power after inital start up. Now I really don't have any warm starts, i drive it to work and back home. It is hard to start cold now too, with hesitation and sputtering for about the first minute then its fine. any ideas? I saw the posts on fuel regulator. not sure if thats it because they all have troubel warm starts

Keith

I have a 1999 5.3 silverado 172k miles. recently started having problems starting when warm. It would start but took 2 or three cranks then ran rough for a few seconds. It ran fine and had lots of power after inital start up. Now I really don't have any warm starts, i drive it to work and back home. It is hard to start cold now too, with hesitation and sputtering for about the first minute then its fine. any ideas? I saw the posts on fuel regulator. not sure if thats it because they all have troubel warm starts

Keith

Pull vacuum line off reg and look for gas in it.
Lot of fuel pressure regulator problems with the 5.3 engine.
Run a full fuel pressure test.
Cold start and engine running and on the roadfm and hot start.
Make sure presure is up to specs and no fast leak downs.

How many miles on it and last tune up?
Pump or fuel regulator ever been replaced?
Good Delph fuel pump or after market?

I have a 1999 5.3 silverado 172k miles. recently started having problems starting when warm. It would start but took 2 or three cranks then ran rough for a few seconds. It ran fine and had lots of power after inital start up. Now I really don't have any warm starts, i drive it to work and back home. It is hard to start cold now too, with hesitation and sputtering for about the first minute then its fine. any ideas? I saw the posts on fuel regulator. not sure if thats it because they all have troubel warm starts

Keith

I have the same engine 2000 sil 5.3L ..

with no codes this may mean a restricted fuel filter or a low fuel pressure..

the fuel regulator has never failed yet for me..130,ooomi now on it. this regulator has a vacuum line.when the engine is not running or WOT , this will create max fuel pressure, [no/low vacuum] when idling this is max vacuum so the pressure will drop..53 psi is the low end of the spec... the high end is about 62-65 psi...If the regulator has a torn diaphram this will mess up the fuel delivery ...and effect starting because it will suck fuel directly into the intake..driver side plugs get fouled..

injectors may be dirty. if so they can leak and flood engine..check for this.

one way is to measure fuel pressure on engine shutdown see if the pressure holds to with in a few psi after 15min...

the min psi is 53psi with engine on ..

the use of techron injector cleaner is what I use every few thousand miles with a few ounces of marvel mystrey oil to the fuel..runs very smooth ...also get the 41-110 ac delco spark plugs ..this engine is picky on plugs...

my engine is very smooth running ...surprising with the age and mileage.

another no code item is the ECT with cold starting issues..this can get out of spec and cause the PCM to think the engine is at normal operating temp or its 40 below zero ...when this occurs the engine will not start or starts very poorly and will sputter etc...make sure the connections are clean and the connector/wires are good shape also.

instead of hunting for the regulator, anyone know where it is on teh 5.3?

instead of hunting for the regulator, anyone know where it is on teh 5.3?

what are the fuel pressures ? you still messing with this ?

get a repair manual to find what/where the components are /look like !

If you have no knowledge or someone who does , that can asist you ..you should have this repaired at a local repair shop..

I have not really been messing with it. I've been gathering info on the web..as far as hunting the regulator, I thought a forum would keep me from laying under the truck to hunt and trace out the fuel line and vacum lines to find it. sorry for trying to save a few minutes. Just because someone uses a website doesn't mean they never turned a wrench. I think I paid 2 times for a repair at the shop since ive been driving a total of 25yrs. I know a little about auto repair.

Do you know what size bolts hold the fuel pump on a 66 chrysler newport? how about a 79 dodge diplomat? we all know what the fuel pump looks like and general location and is bolted to side of engine, but someone who was there before could tell you some of this info; thus saving a step.

Just responding to jcats smart reply.

instead of hunting for the regulator, anyone know where it is on teh 5.3?

The fuel pressure regulator on the 5.3 engine will be on the drivers side fuel rail that sits on the left hand injectors.
About the middle on side.
Little fellow not muck over a in around with a vacuum line running to it.
After engine run and set 5-10 minutes when you have a hard start.
First step is pull the vacuum line and look for fuel in line.
A good fuel pressure check will show a bad regulator or fuel pump.

My brother in-law has had to replace his 4-5 times.
After market and GM and all have bad or go bad real quick.
And back to the slow or hard start warm and hot.

Good AC delco plugs and good fuel Delphi fuel pump with a good fuel pressure regulator holding proper fuel pressure are the proper steps to keep GM truck 5.3 engine starting and running good.

I have not really been messing with it. I've been gathering info on the web..as far as hunting the regulator, I thought a forum would keep me from laying under the truck to hunt and trace out the fuel line and vacum lines to find it. sorry for trying to save a few minutes. Just because someone uses a website doesn't mean they never turned a wrench. I think I paid 2 times for a repair at the shop since ive been driving a total of 25yrs. I know a little about auto repair.

Do you know what size bolts hold the fuel pump on a 66 chrysler newport? how about a 79 dodge diplomat? we all know what the fuel pump looks like and general location and is bolted to side of engine, but someone who was there before could tell you some of this info; thus saving a step.

Just responding to jcats smart reply.

these forums are used to help owners and others to find solutions to the repair of these vehicles failures.

this is not a auto mechanic repair school training forum..

for your safety and to make a proper repair you need a manual. with your comments above it appears your knowledge is decades old. this requires you to spend a small amount of money to acquire the location and function of these new components ...

fuel pump mounted on the engine that is very funny !

I have not really been messing with it. I've been gathering info on the web..as far as hunting the regulator, I thought a forum would keep me from laying under the truck to hunt and trace out the fuel line and vacum lines to find it. sorry for trying to save a few minutes. Just because someone uses a website doesn't mean they never turned a wrench. I think I paid 2 times for a repair at the shop since ive been driving a total of 25yrs. I know a little about auto repair.

Do you know what size bolts hold the fuel pump on a 66 chrysler newport? how about a 79 dodge diplomat? we all know what the fuel pump looks like and general location and is bolted to side of engine, but someone who was there before could tell you some of this info; thus saving a step.

Just responding to jcats smart reply.

Damn I wish the fuel pump was on the side of motors, it would have saved me many many hours of dropping tanks. Why didn't someone tell me this before?? ;)