cage6902 Posted January 24, 2012 Report Share Posted January 24, 2012 2003 Silverado 5.3L, 180k miles. Truck take several additional starter rotations to start engine only when truck has been sitting up all day and it is fairly hot outside. Once cranked, it always runs fine. It never does it if it is cold out, if it has just (or recently) been cranked, or if you barely pre turn the igition from run position toward start position without starting...let off, then start. I replaced starter, batt, plugs, and ignition switch. Is the fuel pump or something losing pressure during day maybe? Do i need to replace the pump? Or is there anything else i should check first. Quote Link to comment Share on other sites More sharing options...
harriss Posted January 24, 2012 Report Share Posted January 24, 2012 When the fuel line is leaking, it takes a few extra cranks. A fuel leak in the intake manifold will also cause this. Quote Link to comment Share on other sites More sharing options...
2001silverado364 Posted January 25, 2012 Report Share Posted January 25, 2012 Generally, the fuel regulator is at fault for long crank times, especially if it sits a while, but not too long between hard starts. Pull the vacuum hose off the regulator while it's running and see if it leaking fuel into the intake. Quote Link to comment Share on other sites More sharing options...
cage6902 Posted January 25, 2012 Author Report Share Posted January 25, 2012 It only does it if it has been sitting up for around 8 hours and is at least in the 80's. It never does it first thing in the morning; even if it sits all weekend...so temperature and time are the factors. I will check for leaking fuel in the intake and repost. Thanks for the help. Generally, the fuel regulator is at fault for long crank times, especially if it sits a while, but not too long between hard starts. Pull the vacuum hose off the regulator while it's running and see if it leaking fuel into the intake. Quote Link to comment Share on other sites More sharing options...
cage6902 Posted January 25, 2012 Author Report Share Posted January 25, 2012 Took vacuum hose off regulator and it did not spit out any fuel while running. It did, however, make the engine idle a whole lot better. Normally engine idles up and down but always stays running. I wonder if the regulator has something to do with the idling issue and the cranking issue? It only does it if it has been sitting up for around 8 hours and is at least in the 80's. It never does it first thing in the morning; even if it sits all weekend...so temperature and time are the factors. I will check for leaking fuel in the intake and repost. Thanks for the help. Quote Link to comment Share on other sites More sharing options...
2001silverado364 Posted January 26, 2012 Report Share Posted January 26, 2012 (edited) How long did you leave the hose off the regulator, it could take up to 5 minutes for fuel to start coming out without the vacuum assisting it. Was the inside of the hose wet or smell like fuel(not oil). If it idled better with the vacuum leak (from pulling the hose off the regulator), then the throttle body might be dirty. Edited January 26, 2012 by Mr. 3/4 ton SS (see edit history) Quote Link to comment Share on other sites More sharing options...
cage6902 Posted January 26, 2012 Author Report Share Posted January 26, 2012 i will retest it longer tonight and smell it. I have been reading up on the best way to clean the throttle bodies. Any suggestions? Quote Link to comment Share on other sites More sharing options...
2001silverado364 Posted January 26, 2012 Report Share Posted January 26, 2012 Well I take the throttle body off when I clean them, three bolts is a lot easier than having to reach back in there with a rag or toothbrush to clean it. I don't think the 03 up TB's have iac valves, so just clean all around the butterfly, come to think of it, I'm not sure if the butterfly can be manually pushed open on the 03+ tb's either. If you can't push it open, you may have to leave it on the truck and get someone to push the gas to clean around it. Quote Link to comment Share on other sites More sharing options...
Fireman31 Posted January 26, 2012 Report Share Posted January 26, 2012 You can push the '03+ TB's open to clean them.... .....IMO, instead of farting around with the regulator, just replace it, they are cheap, and the old one has a ton of miles on it. If that doesn't fix it, it's time for a fuel pump and filter....... Quote Link to comment Share on other sites More sharing options...
cage6902 Posted January 31, 2012 Author Report Share Posted January 31, 2012 I cleaned the trottle bodies this weekend. Will know if this changes the cranking issue when leave work today since it is a warm day. It is idling better,but is a little higher idle than before...i assume this will settle down after i run it a while. that was simple to clean the throttle boddies, howerver, guys- i blew that dang red straw right off in there like everyone said not to do. So, took the valve off and found the straw way inside.... I did take the vacuum hose off the fuel regulator again for 6 minutes and not sign of fuel coming out. Quote Link to comment Share on other sites More sharing options...
cage6902 Posted February 6, 2012 Author Report Share Posted February 6, 2012 Truck still has the orignal cranking issue. Runs better since cleaned the throttle bodies, but still takes a few additional turns to start when hot out and has sat up all day. I will change fuel filter, but am thinking issue is fuel pump. Quote Link to comment Share on other sites More sharing options...
Slammed05 Posted February 6, 2012 Report Share Posted February 6, 2012 Dude I don't know if this will help. But my truck was down for 2 weeks not knowing what the he'll was wrong with it. It wouldn't crank at all. Changed alot starter, fuel pump, relay, ignition etc. Anyways ended up it was my knock sensor under the intake manifold both went out. 2 50$ parts. It started right up after we changed it. Just throwing that out there to you. Good luck. Quote Link to comment Share on other sites More sharing options...
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