timming may be off

[mansopoor]

let me explain what happened i had coolant going into the oil but it seemed to stop so i change the oil and it seem to be fine. my wife to took the truck one night and it shut off, when i went down to get the truck the dip stick was FULL and WHITE, i drained the oil and and put fresh in and tryed to start it to make sure the motor wasn't gone but i won't start. it's almost like it out of time---(back fires out of throttle body, and just the way it wineds over) maybe it jumped a tooth.and i can't fine the timming marks to line it back up to tbc. PLEASE HELP I NEED TO GET TO THE MALL FOR CHRISTMAS GIFTS.

[MT-2500]

Year and engine and engine code?

Have you got spark and fuel and compression?

[mansopoor]

it's a 98 with a 4.3 vortec, i dont know the code and i have spark and fuel but i dont have a compression test

[MT-2500]

Originally Posted by mansopoor

it's a 98 with a 4.3 vortec, i dont know the code and i have spark and fuel but i dont have a compression test

The timing is not adjustable,
Look behind water pump and left and right side of crank pulley for any timing marks.
No 1 at TDC compression check dist rotor as in dist setting link.

http://files.automotiveforums.com/ga...hp?photo=51302

If the timing chain has jumped much you will have low compression.

Make sure the fuel pressure is around 65 lbs and good hot blue spark to more than one spark plug.
Will it fire off with a squirt of carb cleaner.
Any security lights staying on?

MT

[DelCoch]

It’s quite possible you’ve got a blown head gasket between two cylinders, allowing compression to cross over to the other cylinder. Or, you could have water in a cylinder causing hydro lock. I would take all the spark plugs out and then see if the engine will then turn over like it should.

[mansopoor]

if i disconnect the coil the motor turns over ok. with the coil hooked up, it turns over but stops, it almost seems like its locking up, if i let go of the key and try it again, it will turn over for about 5-10 revalution and stop again. When the coolant went into the oil i was told to dain the oil and turn over the motor in case it had a compression lock in the cylinder, so I did, and replaced the oil. I got the truck to run for about 20-30 seconds but it was bougin and back firing thats what made me think of the timming chain, oh the motor has 260.000km on it.

[blazes9395]

I don't know if I got this right. You drained the oil, turned the engine over, and then replaced the oil? Was the engine without oil when you turned it over? I might be wrong here, but just in case this is what you did, never run/turn over the engine without oil in the crankcase. Thats simply wrong. This sound like it is out of time. When you go to start it, it turns over a couple of times and it back-fires, does the power go out for a split second? If you didn't touch anything on the engine, it most likely the timing chain has jumped. You have to find out where the coolant is getting in the engine. It could very well be bad intake gaskets, or of course head gaskets, like mentioned before.

A compression test will help you find if you have a head gasket leak. At this point, you need to see how coolant is getting in the engine, get that corrected, get it timed properly and hope the bearings were not badly damaged due to coolant contamination.

Good Luck

[blazes9395]

Originally Posted by mansopoor

if i disconnect the coil the motor turns over ok. with the coil hooked up, it turns over but stops, it almost seems like its locking up

I read over this, its out of time for sure, now you have to do some testing to see what caused this to get it back to where it has to be.

[DelCoch]

Originally Posted by mansopoor

. . . the motor has 260.000km on it.

Does the engine have 260,000 Kilo or miles on it. If Kilo, that would equal 161,600 in miles, which isn't all that bad if it has had any kind of regular maintenance at all. In which case, with all the electronic crap on the engine I would suspect sensors, the coil/ignition module, etc, before a timing chain. However, as MT suggested, bring #1 cylinder up on compression and see if the rotor is lined up inside the distributer cap to the #1 spark plug terminal, and go from there.