no start problem

year 200 suburban, 1500 LT, 2wd, 5.3L engine, 212,000 miles. Engine stopped abruptly after driving approx 2 miles. no restart. scanner codes P0343, P0107. Checked all fuses, no visible wiring defects. plugs replaced about 60,000 miles ago. Camshaft sensor replaced. still no start and same codes. i have fuel to injectors and spark to plugs. Is this a timing problem? ?timing chain broken? This is a frustrating problem. thanks for help.

 

There are many reasons as to why these DTC's are set. By the looks of things, neither of these codes will cause the vehicle not to start, as running the vehicle at idle is required as part of the diagnosis of both DTC's. I'm wondering if maybe the fuel pressure regulator is leaking, causing some of the plugs to foul out. Try starting the truck, but hold the gas pedal down to the floor for about 5 seconds, then let off the pedal while still cranking. See what happens when you do that. If it acts as if it wants to start, it could be flooded. Holding the pedal to the floor is referred to as "clear flood mode". Let us know what it does.

Also, you missed the last number of the year of the vehicle. Could you let us know exactly what year your truck is please?

 

One other thing, is your fuel gage accurate? These fuel level sensors like to take a dump, and read inacurately. Seen it a number of times in the shop. You will have fuel to the injectors, but not enough to start the vehicle; insufficient fuel pressure due to low fuel in the tank.

 

Thanks for comments. Car is year 2000. Engine does have signs of being flooded, plugs which I replaced today were all gasoline fouled, and strong odor of gasoline when trying to start . I tried your suggestion of holding down pedal for 5+ seconds; engine "tries" to start but doesn't. Just confirmed that there is compression which should eliminate possibility of broken timing chain. I'll look at fuel pressure and replace if needed. Thanks again.

 

yes it sounds like a leaking fuel pressure regulator i would plull the vac hose off and see if it has gas leaking out


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I added 5 gals gasoline to tank from gas can. No start. Replaced fuel pressure regulator, still no start, and still smells flooded, and backfires out throttle body after turning starter for about 15 seconds. Could timing be off? There is spark to plugs.

 

Timing can cause backfiring out the TB so you could check that with a light gun.

Sounds more like an ignition issue then a fuel issue.

 

well there isnt a procedure for checking times as it is dist less ignition system

i wonder if u have something like a broken cam which would cause your backfiring and also set ur code for camshaft

i would do a cylinder leakage test next to try to pinpoint more if the backfiring is being caused by a mechanical problem

 

Oh, I forgot about the cams on these things. We have see 2 break in the last 5 or 6 years, however, have heard of more.

 

was at the training center the other week and they talking about all the cams breaking but we have not seen a one by us

strange how it goes in streaks like that one area sees so many of something

 

I pulled valve cover on left side. no movement of any valves when engine turns. ?timing chain broken? At least I believe i need to remove timing chain cover, but need advice on removing extremely tight crankshaft balancer bolt. Do I need this tool that holds flywheel at starter site? again, appreciate advice. thanks.

 

None of the rockers move when the engine is rolled over , then yes, remove the timing cover.

I will list the steps to do this, just for the hell of it.

Remove the fan shroud, fan, and water pump.

Remove the balancer, it lists a GM special puller to do so, looks to me like a regular 3 jaw puller with a blunt end that presses agaist the front of the crank.
The flywheel tool would help, but not necessary. You could clamp a vise grip on the flywheel to keep it from turning, I hope.

Remove timing cover.


Before we get too far here, we will wait to go further when you verify the damage. Its either gonna be a broke timing chain or a broken cam at the first bearing journal.

Br1an and I have all the torque specs and proceedures to help you get this thing fixxed. Let us know whats up .

 

yes a 3 jaw puller will work

when you get it apart let us know what you will find i will check tomorrow from work if you have any other questions

 

Well, it was the timing chain, broken and laying in oil pan. Camshaft and crankshaft sprockets appear undamaged, but there is a 'bushing" behind crankshaft sprocket that is scored. I"ll look it over more carefully in am tomorrow. I'm concerned now that I attempted to start engine with broken timing chain, and some valves could have been open. What are chances that I damaged valves or bent valve stems?

Thanks again for all input and advice. And a big thank you to WD40!!

 

There are chances of valve damage. A cylinder leak down test would verify if there is any damage.