Crank no start

[rnfdkwap]

Good Afternoon! I'm new to the forum and this is my first post on any bulletin board, so I hope I'm doing it correctly!?!

Purchased a used 2004 Trailblazer LS EXT with 4.2L I-6, for my son's first car. Engine was rebuilt 46,000 miles prior to purchase at GM dealer. Drove it home with no problems, no check engine lights, nothing! Ran for a week while he spent time giving it some much needed TLC. Went to start it to take it to the tire store and no start. It would crank and crank, but never start.

Did the following diagnostics:

Checked ignition switch, long story, but ultimately ended up replacing the switch. Unfortunately same issue, crank no start.
Checked fuses, I've read a few of the posts and have checked all the fuses mentioned, all are good.
Battery was tested ok, even swapped it out with the battery in my 2500 hd, both batteries worked in my 2500 HD.
checked compression on the first 2 cylinders from the front of the engine back, with the old garden hose technique. Don't have a compression tester.
Checked spark by removing plug and arcing to ground, found it worked the hard way, I was touching the frame, YUOSA!
Can smell fuel in the throttle body and noise coming from the fuel pump.
Tried starting fluid in the throttle body, nothing, not even a snort.
No codes in the computer, probably because I had the battery disconnected for about an hour.

I'm at a loss, not sure where or what I should do next? Any HELP would be appreciated!

Thanks in advance!

 

[The_Roadie]

Welcome! You've done most of the right things. If the throttle body has never been cleaned, some owners have found the butterfly valve stuck shut with tar and gunk. Recommend removing and cleaning it.

To prove it, try injecting starting fluid past the throttle body using the vacuum line to the brake booster.

Instructions: http://gmtnation.com/f25/how-clean-4-2-inline-6-throttle-body-221/

 

[rnfdkwap]

wife's toothbrush,
can of cleaner,
carbon soaked towel,

1 cleaned throttle body, PRICELESS!!!

tried starting fluid but no luck.

 

[triz]

Wow that was really dirty! You said your getting fuel...can you hear the pump turn on?

You checked for spark...good. How is the engine cranking does it sound slow, fast or is it a normal crank?

 

[rnfdkwap]

Well at first it was a slow crank, then it changed to a fast crank, although it seemed to be a slight difference only.

 

[triz]

Hmmm. Any way you can upload a video or audio clip of when you crank it? How did your plugs look when you pulled them?

 

[rnfdkwap]

The video is too large to upload, not sure how to share it at this point. any suggestions???? it is 8.6 MB

 

[gmcman]

Ran for a week while he spent time giving it some much needed TLC. Went to start it to take it to the tire store and no start. It would crank and crank, but never start.

What was the TLC? Could it be something you last did, perhaps an electrical connection?

You may have leaking injectors and the plugs could be fuel fouled. When you pulled the plugs, were they dry?

Does it have oil?

Did you pull any fuses or try to jump start it at any time?

 

[triz]

Upload it to YouTube and give us a link so we can all listen or you can use googledrive.

 

[djthumper]

The video is too large to upload, not sure how to share it at this point. any suggestions???? it is 8.6 MB

A lot of us store photos on PhotoBucket and videos on YouTube.

 

[rnfdkwap]

What was the TLC? Could it be something you last did, perhaps an electrical connection?
You may have leaking injectors and the plugs could be fuel fouled. When you pulled the plugs, were they dry?
Does it have oil?
Did you pull any fuses or try to jump start it at any time?

Vacuumed and cleaned carpet with automotive carpet cleaner. Didn't notice anything out of place, other than the dirt! Hmmmm an interesting thought though..... I will look into this aspect further tonight...

OIL YES
Plugs DRY

Yes pulled all of them one by one, also used a test light to check each fuse in both fuse blocks. tested the relays by switching with another vehicle that had the same relays. yes tried to jump start and had same results, crank no start.

 

[gmcman]

Vacuumed and cleaned carpet with automotive carpet cleaner. Didn't notice anything out of place, other than the dirt! Hmmmm an interesting thought though.

Did you get the carpet cleaner from the dealer or aftermarket? The 4.2 is VERY picky.

Just trying to backtrack your steps, not sure if TLC is mechanical or asthetical.

What you need to do is the following:

Pull intake hose from TB and have someone look into the TB and watch the throttle butterfly. Turn the key to ON, step on gas pedal and see if butterfly is opening.

Try to start engine and if it won't start, step on gas pedal while cranking and observe butterfly for movement.

Pull the CPAS connector and try to start, this will likely throw a code but try it anyway.

You need to verify fuel pressure, you may get drips from the injectors but you need a mist. I doubt this may be the issue but needs to be verified.

Do you have any fuel leaking around the FPR? (Fuel pressure regulator)

Still may have a faulty ignition switch, but try the above first.

I have asked this before for someone else but are you sure there's gas in the tank and not diesel? Happens more than you think since the nozzles are the same size now. Drain a little from the fuel pressure test port on your finger, if oily then you have issues.

 

[rnfdkwap]

Upload it to YouTube and give us a link so we can all listen or you can use googledrive.

Thanks!

Here is the video link: [video=youtube_share;WT03hFeOK7E]http://youtu.be/WT03hFeOK7E[/video][

 

[rnfdkwap]

Did you get the carpet cleaner from the dealer or aftermarket? The 4.2 is VERY picky.

Just trying to backtrack your steps, not sure if TLC is mechanical or asthetical.

What you need to do is the following:

Pull intake hose from TB and have someone look into the TB and watch the throttle butterfly. Turn the key to ON, step on gas pedal and see if butterfly is opening.

Try to start engine and if it won't start, step on gas pedal while cranking and observe butterfly for movement.

Pull the CPAS connector and try to start, this will likely throw a code but try it anyway.

You need to verify fuel pressure, you may get drips from the injectors but you need a mist. I doubt this may be the issue but needs to be verified.

Do you have any fuel leaking around the FPR? (Fuel pressure regulator)

Still may have a faulty ignition switch, but try the above first.

I have asked this before for someone else but are you sure there's gas in the tank and not diesel? Happens more than you think since the nozzles are the same size now. Drain a little from the fuel pressure test port on your finger, if oily then you have issues.

I'm thinking more like possessed!

What is the CPAS? And where might I find it? Sorry, I know enough just to be really dangerous, which most of the time keeps things interesting!!!!

The ignition switch story......

I thought that this could be the issue initially, I tested it by watching the video provided in this forum.... forgot who created it but thanks!!!!! It tested ok. I tried to start and the key had no spring tension.... it had it just before I used the test light to check the wire harness. So i bought a new one and put it in, but it had the same problem, no spring tension. I missed somewhere to line up the teeth, this is the dangerous part i mentioned! So, after another switch and more research found that you need to line the teeth up with the original switch, well it seems a helper... wink, wink, moved the switch from it's position after I removed it from the vehicle. so I had to play with the placement of the switch to get it to activate everything and crank...... I've tried moving the gear on the switch a tooth at a time, but no luck!

I will try the steps listed above tonight..... Thanks.

 

[gmcman]

From my crappy cell phone it sure sounds like its cranking kinda fast. What plugs are in there and i would try to get an accurate compression test on a few cylinders.

 

[gmcman]

You also need to verify TB opening.

 

[rnfdkwap]

You also need to verify TB opening.

Here is another video on the Butterfly operating, kind of scared my helper...

[video=youtube;dRHSMSbBUyg]http://www.youtube.com/watch?v=dRHSMSbBUyg"]http://www.youtube.com/watch?v=dRHSMSbBUyg[/video]

 

[The_Roadie]

And if you spray starting fluid in there is fails to respond? Maybe you had a stuck butterfly valve, and after the cleaning you now have a lack of spark.

 

[rnfdkwap]

And if you spray starting fluid in there is fails to respond? Maybe you had a stuck butterfly valve, and after the cleaning you now have a lack of spark.

So we tried it with starting fluid sprayed and pedal to the floor, nice FLAMAGE! However, we could only get it to flash once, tried it again twice and no luck.

[video=youtube_share;tVGsVhki_YA]http://youtu.be/tVGsVhki_YA[/video]

 

[gmcman]

Sounds like it's cranking too fast you need to verify compression and now you need to verify camshaft timing

 

[gmcman]

A garden hose isn't going to cut it, this engine should push a little over 200 psi in each cylinder

 

[gmcman]

I just want to offer a word of caution before you go venturing inside the timing gear cove be very careful and do not remove anything unless you have an understanding of what's going o don't try to remove anythin because without this would require removing the front cover and to do that you need to drop the oi this would require removing the front cover and to do that you need to drop the oil pan

 

[rnfdkwap]

I just want to offer a word of caution before you go venturing inside the timing gear cove be very careful and do not remove anything unless you have an understanding of what's going o don't try to remove anythin because without this would require removing the front cover and to do that you need to drop the oi this would require removing the front cover and to do that you need to drop the oil pan

Thanks, that's why i'm here, to make sure I don't push my inexperience to far. I will get compression tester tomorrow and update tomorrow night.

 

[gmcman]

I just want to offer a word of caution before you go venturing inside the timing gear cove be very careful and do not remove anything unless you have an understanding of what's going o don't try to remove anythin because without this would require removing the front cover and to do that you need to drop the oi this would require removing the front cover and to do that you need to drop the oil pan

Ha....I just saw this and it's... NOT, what I typed into my phone.

What I was attempting to write, was before you attempt to remove anything timing-chain related, be sure you know what's going on. There's a tool and a procedure to secure the timing chain tensioner and I don't know exactly what it does but it either holds the tensioner or chain so it doesn't move or slip off the crank, or keeps the tensioner in place. If it does fall, then you need to pull the front cover, and you can't pull the front cover unless you drop the oil pan.....big job.

Sounds like you either have a lot of carbon under the valve seats, or possibly the tensioner is bad and you may have jumped the timing chain a tooth or two. Either way, based on your vid, sounds like it's cranking easy like the spark plugs are removed, thus lacking compression.

 

[triz]

Your timing is off! Kind of what I suspected. No question about it. Now the question is, is it the cam timing or its completely off. If your lucky its just the cam timing.

If its the cam, he might be able to get away with securing the chain with a piece of good string or small rope when you loosen the chain tensioner. Then rotating the cam to the proper position.

 

[rnfdkwap]

GRRRRRR UPDATE:

I checked 2 cylinders no compression..... Took out spark plugs this time 2 of 3 are oil soaked, dripping of oil..... I'm guessing this means new engine or different vehicle

 

[gmcman]

The lack of compression is likely from the valves hanging open since the cam timing is likely all screwy. Possibly have a bad tensioner allowing the chain to jump a tooth. You need to pull the front timing chain cover, the part with the oil cap and see what's going on. Hopefully you don't have any bent valves and it's just a tensioner.

Right now it looks like worst case a head if the valves are bent, but just take it step by step

 

[triz]

Its possible that you might have bent a valve with the cam timing off. You could have gotten lucky and its just keeping the valves open and that's why you have low compression.

You can correct the cam timing without having to remove the TC cover. Then try and restart the truck an recheck your compression numbers.

If you bent the valves your going to have to remove the head. Similar to doing a headgasket. Your block and head is likely still good.

I've had my cam timing off by 180 degrees and did not bend a valve. So I still have my fingers crossed for you.

 

[rnfdkwap]

How do I correct the timing chain without taking the cover off?

Also, the compression tested at 0, does that make a difference?

Also, the engine has 206K, and appears that only the top half of the motor was actually rebuilt?!

 

[gmcman]

needs to come of not the whole front cove

 

[gmcman]

Sorry this phone is complete garbage the black front cover that hold the oil cap needs to come off not the entire front cover

 

[triz]

Sorry this phone is complete garbage the black front cover that hold the oil cap needs to come off not the entire front cover

Yeah your phone sucks..lol

If you want to give it go and try the cam timing first. Remove the top oil cover as GMC was trying to say. I have not had a chance to check on the position of the cams for you but if you download the manual it should be on there. After you get that worked out you can check the compression. If its still screwed up you've likely bent the valves and well, off with its head.

If you were local, I'd gladly give you hand.

 

[rnfdkwap]

Where can I find the manuals?

I wish you were local as well! Although Michigan is a great place to visit! I guess the same can be said for Florida!

I will take apart the cover Sunday evening.... Getting ready to head out of town for the weekend.

THANKS AGAIN to you both!

 

[triz]

I have not had a chance to look yet but you might find it in here.

http://gmtnation.com/f23/need-service-manuals-get-them-here-371/

 

[rnfdkwap]

Well, after moving the vehicle to a friends garage and having time to work on it, we've found the timing chain intact, but very loose. Appears the tensioner is bad, we think... Ordered the timing chain kit, won't be in until next week. going to remove the radiator this weekend, unless someone knows a work around? Any do's or don't's would be greatly appreciated!

Thanks for all the help thus far!

 

[triz]

I would think with this type of job you want as much room to work as you can. Make sure you get the timing right. Godspeed!

 

[gmcman]

Don't know off hand but there's a tool that secures the tensioner. I don't know if there is a DIY tool but hopefully someone can chime in, I'm hitting the road in the AM so I wish I could add more to this.

This is the important part....

Don't drop the chain.

Before you tackle this job, know what you are loosening/removing and what needs to be secured. I haven't been inside mine so I don't have any hands-on yet.

Rotate the engine 3 times to ensure the timing marks are lined up when finished. I don't know how you look at the crank gear to ensure the marks are aligned without removing the cover...hopefully you don't have to.

If you do need to remove the entire front cover, replace it. This way you get a fresh oil pump.