Hard/ no start... agian

[Ceejkay]

Went out to start the truck yesterday i got like a second of it cranking then it stopped dead in its tracks.. Almost as if it was locked up.. I can put a socket on the crank pully and it spins, so its not actually locked up. I had this problem about 2 months ago and got it fixed.. New crank shaft position sensor, new cam shaft position sensor, new coil, cap, plugs wires, spider assembly, and a new starter. Before this happened it was running rough again.. My laptop died so im going to have to borrow a reader to see the codes...

So what do you guys think? replace most of that stuff again? The only thing different from the last 2 months was a cold week or 2 and some rain.. Also in the last 2 months it has been driven about 300 miles.

 

[SunlitComet]

how about running a fuel pressure test this time around.

 

[letsbangout]

then it stopped dead in its tracks.. Almost as if it was locked up..

I'm going to assume for the moment that you mean to suggest that the motor becomes hard to turn, while it's in the process of turning over. There is a TSB for 99 Yukons (I presume it applies to your truck too) indicating that a deficiency in the crank position sensor or it's circuit, can command up to 50 degrees of ignition advance, making it very hard to turn over and possibly cracking the starter mount boss or the flywheel ring gear. It's possible you've got an intermittent crank position sensor or circuit, or perhaps you needed (but didn't obtain) a crank relearn procedure since you made no mention about it above. I recommend digging up the TSB and scanning for codes. FWIW, my 99 Yukon is hard to turn over sometimes, probably as a result of the sensor, or "drift" in values over time, etc. When I first bought it, it did the same thing while starting.. it would turn over, then get hard to turn and stop for about a second, then it'd start turning again and fire right up. It's gotten much better about this over time but it still happens in "phases" from time to time. I've gotten my battery checked plenty of times to be sure and it always reads around 530 of 550 CCA. However, that doesn't rule out the possibility that my problem (or yours) could be related to a weak or sticky starter.

Also, that's not to downplay the advice you were given above, a fuel pressure check is a pretty elementary when trying to diagnose a no-start problem.

 

[Ceejkay]

how about running a fuel pressure test this time around.

when i say hard start i mean the flywheel wont even turn.. starter is engaging.. the timing being off is what i was leaning towards, because i didnt do the relearn.. (insert bunch of cursing on my part) but i will check the fuel pressure anyways.. and i did partially complete the tsp i guess...

 

[SunlitComet]

Ceej load test your battery and make sure you down have broken wires that are limiting power to the starter. it may just be week enough to stall at the top of compression stroke.

 

[Ceejkay]

ok so i rotated the flywheel by hand for about 2 revolutions.. went in and it started right up.. im thinking i need the crank relearn asap..

 

[SunlitComet]

you sure you aren't getting fuel dumped in there randomly.

 

[gpracer1]

you sure you aren't getting fuel dumped in there randomly.

He coud probably pull the dipstick and see if it smells like fuel.

 

[Ceejkay]

He coud probably pull the dipstick and see if it smells like fuel.

which it doesnt

 

[letsbangout]

I found another thread where you mentioned having hardware/software from scantool.net and that you're interested in doing basic tuning with it. Is it possible that something you programmed has caused a severe ignition advance?

 

[Ceejkay]

i never got into it. i really have no idea what to do for tuning and didnt want to screw anything up..

My coolant leak is back .. since an engine cant compress water i think this might be the source of my problem.. best case scenario, just do the intake gaskets(if i had the extra money a couple months ago i would have done them while i was in there).. worst case, head gaskets...
hypothetically: so going with worst case here.. if i have to pull the heads to do the head gasket is there any reason not to take it to a machine shop for a full valve job?


also just pulled the plugs and they are wet from fuel...

 

[SunlitComet]

I think it it is time to tear it down for inspection, repairs and upgrades if needed. I would wait until you look at the bigger picture to see where the weak spots are and concentrate on just those. And post pics for help with diagnosis.

 

[Ceejkay]

yea im thinking the same thing... and what do you mean by bigger picture? first thing on the list is to get this p1345 resolved.. then work from there..

 

[SunlitComet]

the overall condition of engine. If possible to get it running and hot one more time do compression test to judge the overall condition of the block before tearing it down. It will be a good starting point And while they are out examine and pics your plugs for review and advice here among other things. For the timing I can't recall you did realign the dizzy correct but did not do a case relearn?

 

[Ceejkay]

i never removed the dizzy, just did cap and rotor.. and i agree with the comp test... i got a hold of a scanner today and the only code im throwing is the p1345.. i also found out orileys here doesnt lend compression test kits..

 

[SunlitComet]

auto zone does. Does that scanner read "CAM_RETARD"?

---------- Post added at 06:51 PM ---------- Previous post was at 06:48 PM ----------

if chain and gears are in good shape you can solve the p1345 alignment without a scanner but you will need patients to get it good enough.

 

[Ceejkay]

Ok so i got a compression test done this am.. Started the truck up this morning and let it run for about an hr.. pulled all the plugs.. heres what im looking at for values..
1-100psi
3-90psi
5-75psi
7-90psi
2-98psi
4-75psi
6-90psi
8-95psi

Now after letting it sit an hr or so(charging the battery), i went out to crank because it sounded weird while doing the test.. i noticed water coming out of plug hole 5.. When cranking i get a weird chattering sound, and it doesnt sound like the valves but since no plugs are in its probably what it was.. Any ways here are the plugs
1,3,5,7

2,4,6,8

this is what i used for instructions
Disconnect the positive ignition coil wire plug from ignition coil.
Disconnect the fuel injector electrical connector.
Remove all the spark plugs.
Block the throttle plate wide open.
Charge the battery if the battery is not fully charged.
Start with the compression gauge at zero. Then crank the engine through four compression strokes (four puffs).
Make the compression check the same for each cylinder. Record the reading. The minimum compression in any one cylinder should not be less than 70 percent of the highest cylinder. No cylinder should read less than 690 kPa (100 psi). For example, if the highest pressure in any one cylinder is 1035 kPa (1150 psi), the lowest allowable pressure for any other cylinder would be 725 kPa (105 psi). (1035 x 70% = 725) (150 x 70% = 105).
If some cylinders have low compression, inject approximately 15 ml (one tablespoon) of engine oil into the combustion chamber through the spark plug hole.

Normal - Compression builds up quickly and evenly to the specified compression for each cylinder.
Piston Rings Leaking - Compression is low on the first stroke. Then compression builds up with the following strokes but does not reach normal. Compression improves considerably when you add oil.
Valves Leaking - Compression is low on the first stroke. Compression usually does not build up on the following strokes. Compression does not improve much when you add oil.
If two adjacent cylinders have lower than normal compression, and injecting oil into the cylinders does not increase the compression, the cause may be a head gasket leaking between the two cylinders.

Install the removed parts.
Connect the disconnected components.

 

[SunlitComet]

I HOPE TO HELL YOU SCREWED UP THE TEST!!!

Do the test again if not sure.

If not your engine is hearby officially dead and need to be replaced. It sounds like it has done its bit for queen and country and with those pressures a little bit more. Sorry man.

 

[Ceejkay]

yea those are the numbers i saw the 100 first and was like wtf.. then the next being 90.. it looks like im gonna throw some plugs in it till she dies out completely.. or till i get my tax returns.. how do i go about fixing the code?

 

[letsbangout]

Just curious.. have you not put any "barz" into your system to hopefully get a few more miles out of your engine before it gives up the ghost?