2000 5.3 hard to start

silverado z-71 have to pump accelerator and try ignition several times engine stutters then comes to life. Truck runs great once started. Stop engine and same hard start condition immediately. Changed fuel filter. Fuel pump???

Possibly and check the fuel pressure first.GMs will not run under the lowest fuel pressure.

Leaking fuel pressure regulator. Cycle the key (on off on off on off then start) and then try to start.

Leaking fuel pressure regulator. Cycle the key (on off on off on off then start) and then try to start.
replaced pressure reg this am same symptoms , do not have a gauge to check pressure but is it not odd that the truck runs fine once started not lean but strong.

Is it possible that the battery is getting weak and when the starter is cranking the engine over there isn't enough power to get the engine controls up and runnning? Its a long shot but if it seems to be turning over slower that normal than it may be worth having the battery tested and/or seeing what the amperage draw is on the starter.

i'd start with cleaning battery poles/terminals, and lubbing them with dielectric grease.

scan for codes. very possibly one or 2 bad wires or plugs.

please, do not swap parts on a guess, it's the most expensive repair possible.
scan codes, it's free, then we'll see.

btw, how bad is air filter?

i'd start with cleaning battery poles/terminals, and lubbing them with dielectric grease.

scan for codes. very possibly one or 2 bad wires or plugs.

please, do not swap parts on a guess, it's the most expensive repair possible.
scan codes, it's free, then we'll see.

btw, how bad is air filter?
Did the battery deal first off , cleaned and lubed leads, New Interstate chks ok, cranks fine all accs come on line, no fuses blown, checked pump relay, can hear pump come on but still have no way to check pressure. I still don't get the fact that engine runs with authority once started. I will have to take to someone to get codes. There are no chk engine ,etc. K&N ,fresh on the filter, mass air clean, BG just run through system, run Lucas fuel add every tankfull.
186000 on the fuel pump

Did the battery deal first off , cleaned and lubed leads, New Interstate chks ok, cranks fine all accs come on line, no fuses blown, checked pump relay, can hear pump come on but still have no way to check pressure. I still don't get the fact that engine runs with authority once started. I will have to take to someone to get codes. There are no chk engine ,etc. K&N ,fresh on the filter, mass air clean, BG just run through system, run Lucas fuel add every tankfull.
186000 on the fuel pump

i have learned from cars experiences that the worst way to approach a problem is to assume something and just hammering in that direction. better way is, though time taking, to do proper investigation and narrow it down.
go to any major parts store, they will scan it for you for free.

i, personally, am leaning towards electrical supply inefficiency. come to think about it, even just listening to that powertrain start, there are a lot of devices that kick in, all at once, at startup, that don't run so much down the road. thus, any minor to moderate electrical insufficiency at startup can cause this, and then goes away when it all picks up, accessories shut down, and momentum kicks in.
so, you keep saying pump has 186000 miles on it. yeah, so does alternator, correct?
does it have a new belt, for instance? slipping belt can cause mui grande problemo.

points taken, will follow the electical path . Thanks for help, will stay in contact with results

points taken, will follow the electical path . Thanks for help, will stay in contact with results

please, do post when you find codes - or fix it.

such follow ups are most valuable to everyone, we all learn and gain experiences to help others later.

all the best and good luck.

I apologize for not being clearer in my original post. I did not intend to mislead you into thinking the pressure regulator should be replaced. My intention was for you to do the key cycles and if the starting problem resolved itself than the regulator should be looked at closer to see if it has failed. Typically they will leak fuel out of the vacuum nipple when they have gone bad.

I agree, at this point you need to find out more information on what is not doing what it is supposed to. Is fuel pressure to low and is there enough spark. I think the answer to these two questions will be very beneficial!!

points taken, will follow the electical path . Thanks for help, will stay in contact with results

as stated fuel pressure is suspect with poor start...also check for the correct ECT sensor resistance ...if the computer thinks the engine is hot the injectors will not be commanded to stay open long enough to supply the proper fuel richness when cold/cool....


this is common [no codes]

hey it sounds like you have a fuel injector staying stuck open while the vehicle is off. try starting the vehicle with the pedal all the way to the floor if it starts normal one or more of your injectors are stuck open. let me know what happens

Thats a pretty good possibilty. You would think that if it sat overnight it would have enough time to boil off the leaking fuel and possible take a little longer to start but fire up and idle normally. Then again anything is possible.

You would also think that you would get a rich code for whatever side the injector was leaking on?

I have a 2005 Avalanche that is acting exactly the same. My theory, (doesn't mean it is right by any means) is that the issue must lie in the fuel system as was posted earlier in this post. If I turn the key to the on position for a few seconds then it will usually start the first time, but still not as quickly as it used to. If I just get in and try to start it right away it will not fire the first time but will on the second attempt. The truck runs fine once it starts and my fuel mileage is the same as usual. I can't actually hear the fuel pump running as I could in some older cars when I first turn on the key.
I guess I'll go to have the codes read and see where that leads.

I have a 2005 Avalanche that is acting exactly the same. My theory, (doesn't mean it is right by any means) is that the issue must lie in the fuel system as was posted earlier in this post. If I turn the key to the on position for a few seconds then it will usually start the first time, but still not as quickly as it used to. If I just get in and try to start it right away it will not fire the first time but will on the second attempt. The truck runs fine once it starts and my fuel mileage is the same as usual. I can't actually hear the fuel pump running as I could in some older cars when I first turn on the key.
I guess I'll go to have the codes read and see where that leads.


Welcome to AF
On your problem to save on highjacking a post.
Go to the Avalanche forum and start a New Thread/ New post on it and someone will help you.

Beefy
In regards to your PM mail.
I am sorry about jumping your case on hijacking the post.
If your intentions were not aimed at trying to get help on yours and or just adding information.
But information on an Avalanche should be keep in the Avalanche form and information about a Silverado should be keep here.
Also a lot of people think they have a problem just like someone else when in fact a lot of the time it is a altogether different.
Remember proper testing is first in order.
The offer on yours still stands.
If you need help on it start a New thread in the Avalanche form and someone will help you.
Good Luck on your problem
MT

Back folks same deal. Airjer no prob on the regulator. When I repaced it parts fell out, could not tell what, just a couple of chunks. Could have been anything , wierd. Now here's the deal. Only codes were --"ocassional misfires ignition" or the like and no others. I also discovered a 30 amp fuse blown at STD2 in fuse box in engine compartment. new fuse same problem. Tried pedal to metal at start no diff. Still have not had pressue checked have to go to a real tech for that around here. changed plugs and wires this pm. no change except runs stronger. AC Delco plats and Bosch wires. Serpentine belt appears fine, treat with spray silicone every oil change.

Back folks same deal. Airjer no prob on the regulator. When I repaced it parts fell out, could not tell what, just a couple of chunks. Could have been anything , wierd. Now here's the deal. Only codes were --"ocassional misfires ignition" or the like and no others. I also discovered a 30 amp fuse blown at STD2 in fuse box in engine compartment. new fuse same problem. Tried pedal to metal at start no diff. Still have not had pressue checked have to go to a real tech for that around here. changed plugs and wires this pm. no change except runs stronger. AC Delco plats and Bosch wires. Serpentine belt appears fine, treat with spray silicone every oil change.

the fuel pressures should have been checked first , especially with the dtc found [missfires]......then the ECT for proper resistance..


not to mention this fuel pump has 186,ooomi on it... I believe..

should have 60psi of pressure approx , and with turning ignition to off should hold pressure for a few minutes...if it drops rapidly, and the pressure is low you need a fuel pump...not surprising though...

The stud #2 Has to do twith the trailer wiring If i remeber right.

I will get the pressure looked at. own too many vehicles. truck is not my driver. have to commute about an hr every day, Toyota solara for that. will have to find the time to take truck to someone totest will posts reults. THANKS for all yalls input. Glad I found this site.

Ok the fuel pump was the problem. New one had to have wiring harness change (Hope for the best).

Not much fun but I dropped the fuel tank and washed it out. Dryed with air and installed some methanol to make sure no water. New gas 24 gals. need KY at the pump these days. Runs and starts great, BUT selector for auto 4 wheel, 2 wheel, 4 hi or 4 lo wont shft from 4 lo to anything. what did I do???

Checking the FP, basic diagnostics for most driveability issues, this is a lessen in the value of having or checking the most common areas, a lot of money and time can be saved here, even if you have to pay to test some components. Check the plug on the transer case, check the 4wd fuses, also the position switch on these trucks was prone to failure. BTW, glad to see it resolved, it relieves a lot of late night worrying.

Ok the fuel pump was the problem. New one had to have wiring harness change (Hope for the best).

Not much fun but I dropped the fuel tank and washed it out. Dryed with air and installed some methanol to make sure no water. New gas 24 gals. need KY at the pump these days. Runs and starts great, BUT selector for auto 4 wheel, 2 wheel, 4 hi or 4 lo wont shft from 4 lo to anything. what did I do???


now that the fuel pump is replaced how is it that you got into 4 wheel low ? explain step by step what you do ,,,what the vehicle does...step by step....then we can possibly help....

the next step would be to get a DTC of the drive train...186,000mi is usually the encoder transfercase motor....the DTC will show a code that this is the cause....

after installing fuel pump started engine, indicator for 4 lo came on, tried to change , any other choice gives a flashing indicator on that choice which stops flashing after a few seconds, the 4lo indicator never goes off.

after installing fuel pump started engine, indicator for 4 lo came on, tried to change , any other choice gives a flashing indicator on that choice which stops flashing after a few seconds, the 4lo indicator never goes off.

did you disconnect the battery when doing the fuel pump? disconnect the battery for 15 min then recheck ..

Is the vehicle in 4 wheel low? or it is just the lamp light on..

did you disconnect the battery when doing the fuel pump? disconnect the battery for 15 min then recheck ..

Is the vehicle in 4 wheel low? or it is just the lamp light on..

lamp on and in 4lo I did not disconnect battery will try that.

Battery deal not the prob. While trying everything I started truck, applied brake very hard, ran shifter through a couple of times, left in neutral then asked 4wheel drive selector to shift to 2hi and all heck broke loose i could hear a few clicks , apparently at transfer case, the the indicator lights cycled through all settings and settled on 2hi. have driven a few miles, operating selector through all choices, all works ok. Short somewhere???

Battery deal not the prob. While trying everything I started truck, applied brake very hard, ran shifter through a couple of times, left in neutral then asked 4wheel drive selector to shift to 2hi and all heck broke loose i could hear a few clicks , apparently at transfer case, the the indicator lights cycled through all settings and settled on 2hi. have driven a few miles, operating selector through all choices, all works ok. Short somewhere???

so now you have the vehicle in 2wd....? normally when changing the 4wd fuction switch the transfer case motor should move to the correct position in 2-3sec....how many times does the select switch flash when going from 4wd to 2wd or 2wd to 4wd ??? this should be accomplished with the flashing of the lights 3x max....if it takes alot of time you have transfercase problems.. step one is what is the fluid color? level? and if this is good then the DTC must be read ....most likely at your mileage the encoder motor is defective... but need DTC codes to be sure,,, then readings of the motor to be positive... good luck

i have a 2000 chevy with the 5.3L thats hard to start when its warm. it has no problem when it has set but if its shut down for less than a coulple hours it cranks but wont fire up, untill i push the pedal down, altho sometimes i can get it to start without using the pedal but it takes a few tries. it smells like its rich but it runs just fine once its going. i just did plugs and wires, new air filter. the throttle sticks sometimes in the closed position so i figure i need to clean the intake. its has almost 60k on it

i have a 2000 chevy with the 5.3L thats hard to start when its warm. it has no problem when it has set but if its shut down for less than a coulple hours it cranks but wont fire up, untill i push the pedal down, altho sometimes i can get it to start without using the pedal but it takes a few tries. it smells like its rich but it runs just fine once its going. i just did plugs and wires, new air filter. the throttle sticks sometimes in the closed position so i figure i need to clean the intake. its has almost 60k on it

Welcome to AF.

On a 5.3 hard to start hot always look for gas in the vacuum line on fuel pressure regulator.
If gas linkage is sticking clean the TBI buttery fly flipper and housing .
TB/carb cleaner and a old tooth brush does a good job on it.
If you help on yours it is best to start a new post.