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D-17_Dave 
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Joined: 11 Sep 2009
Location: Mocksville NC
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 Topic: 2001 Chevy PU help
Posted: 18 Jul 2010 at 10:42am |
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Hi all, a recent purchase has me a 2001 Chevy pu. When I went to look at it it would fire right up then shut off. It was a fleet vehicle so I walked away. The contact guy called me back and said it will run now so I brought it home. I did put an intake manifold gasket in it and did some damage to the fuel spider tips on cyl. #1&3 so I replaced the spider w/ the new multiport setup. It has been as smooth as I could ever hope for until this morning it started to act up again. It will fire evry time you reset the key from off to start, but as it levels out after maybe a secound of running it shuts off. It is getting fire and it will run as long as you feed it fuel. It has fuel rail pressure so I have it narrowed to the computer is not energizing the fuel injectors. I'm leaning towards a bad crankshaft sensor but I thought I would run it by here before going any further. What do all the other Chevy experts think?
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ChuckLuedtkeSEWI
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Joined: 11 Sep 2009
Location: Jackson, WI
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Posted: 18 Jul 2010 at 12:54pm |
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I had an 02 that I ended up selling. Are you sure it has fuel pressure all the time? The last time I had problems, I put a fuel guage on and it would build up pressure up to where it was supposed to be before starting, but just as it would get up to the right setting, 55 lbs, it I remember right, the pressure relief valve by the fuel pump would kick out and the pressure would go down to 0. Once it was running, the fuel pump would keep the pressure up enough to run, but I would have a hard time getting it started. since the pressure switch is with the fuel pump in the gas tank, I replaced the whole thing and it was fine up until I sold it. I think there is also a pressure regulator on the fuelrail that is vaccuum operated. I tried taking the vaccuum hose off of it to see if that would help but it didn't. I don't know how much the 01 and 02 vary.
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Brian Jasper co. Ia
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Location: Prairie City Ia
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Posted: 18 Jul 2010 at 5:29pm |
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A CKP could do what you describe. I have yet to see a failed one on either a 5.7 or a 5.3 though. I would watch the fuel pressure gauge closely. If you cycle the key without starting and the pressure comes up, then drops off more than a few psi when the pump shuts down, I'd be looking into replacing the fuel pump. Another dead giveaway for a fuel pump is when it dies and won't restart, have someone smack the bottom of the tank with a large rubber mallet. I can get 8 in 10 trucks with bad pumps in the shop that way.
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"Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford
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D-17_Dave
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Posted: 18 Jul 2010 at 9:12pm |
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I've done the tank smack dozens of times on dead pumps. The pump runs if you crank after the engines dies. I can here it after I bring the key back from start position. I will get a pressure gauge on it and completely varify that the pressure stays up. Stupid thing started up an hr after I had it act up and has started and ran all day. Guess we'll see when it acts up again. Thanks though.
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Mike(SC-MN)
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Posted: 19 Jul 2010 at 8:04pm |
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Another thing to check is the security system. Not sure which system you might have on it but some of them shut down the injectors to disable the engine if the security system is activated. If there is a security light on the dash see what it is doing when it won't start. It should turn on for a few seconds and then go off. If it stays on or is flashing there is a problem with the security system.
If the crankshaft sensor was bad you wouldn't have any spark either.
Mike
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<font color=orange>1955 WD45 Wide Front[/COLOR][/COLOR]
Trip Bucket Loader, S/C 3-16 Plow, #3 Mower, Allcrop 66, S/C Subsoiler, Rear Toolbar Field Cultivator, Side Delivery Rake/Tedder
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D-17_Dave
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Posted: 19 Jul 2010 at 9:31pm |
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Thanks Mike for the tips. What does the pick up in the distributor trigger if the crank sensor fires both the fuel and the ign.?
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Mike(SC-MN)
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Posted: 20 Jul 2010 at 12:01am |
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The camshaft sensor is used as a sync signal for the sequential fuel injection.
Mike
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<font color=orange>1955 WD45 Wide Front[/COLOR][/COLOR]
Trip Bucket Loader, S/C 3-16 Plow, #3 Mower, Allcrop 66, S/C Subsoiler, Rear Toolbar Field Cultivator, Side Delivery Rake/Tedder
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Brian Jasper co. Ia
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Posted: 20 Jul 2010 at 6:59am |
So if we have a distributor, we're dealing with a 5.7. Like Mike says, the distributor is the cam position or CMP. If the security system has a failure while the engine is running, it will go into fail safe mode meaning it will deactivate and you will be able to start and stop the engine, unless you disconnect the battery. If the failure occurs when the ignition is off, it will not start. It depends on which product line as to what is disabled. "W" body disables everything, no crank no start. If I remember correctly, trucks are just fuel pump disable. Full size trucks are not known for security system issues.
Do check the fuel pressure and see if you have any DTC's.
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"Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford
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Andrew(southernIL)
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Posted: 20 Jul 2010 at 1:05pm |
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My 2000 GMC will throw a fit every once in a while of dieing as soon as it starts unless you hold the gas but then as soon as you let off the gas it dies. This may sound crazy but all I do is unplug the mass airflow sensor then plug it back in and everything is fine after that.
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If fishing is a sport your looking at an athlete
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Brian Jasper co. Ia
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Posted: 20 Jul 2010 at 6:43pm |
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Andrew, do you have the original paper filter on it still? Those oily cotton filters can shed enough oil and dirt to contaminate the MAF. Try cleaning it. It's best to not use carb cleaner as some carb cleaners leave a residue, and can damage the plastic. You can get MAF sensor safe spray cleaners at most auto parts stores.
Edited by Brian Jasper co. Ia - 20 Jul 2010 at 6:43pm
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"Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford
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Andrew(southernIL)
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Posted: 20 Jul 2010 at 10:41pm |
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I have a K&N intake and filter.
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If fishing is a sport your looking at an athlete
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