Engine not running

Hello,

I don't believe so, and if it did you would have a bent valve and/or bent pushrod. Did you lap the valves into the cylinder head valve seats?

Thanks,
Alex
2CarPros

Yes I did. I'm going to try to adjust the valves using the GM repair manual. I did adjust them using their method, but went 360 again, a quarter turn at a time, and tightened them again! After I adjust them again I'll shoot air into the cylinder and feel or hear for leaks.

Hello again,

Okay, so in the diagrams down below I have included the specs. for the valves on your vehicle's engine and the instructions from the vehicle manufacturer on the procedure for adjusting the valve lash. Please go through these guides and get back to us with what you find out. Also, did you use the same head bolts when you reinstalled the heads on the engine block? I have found doing a search of Technical Service Bulletins[TSB][s] for your vehicle one that deals with the head bolts. Please get back to us with how things are going.

Thanks,
Alex
2CarPros

Hello again!
Yes. I used new head bolts. I have the same manual as you are showing. I'll let you know when completed.

Hi,

The best way to adjust valves is to start on number 1 cylinder TDC loosen both intake and exhaust rocker arms so there is plenty of free play hold the push rod with two fingers and rotate the push rod between your fingers as you tight the rocker arm until you have resistance than stop that valve is adjusted. Do this in firing order each cylinder at a time and the vehicle will start. (The best way is to adjust valves is with the valve covers off vehicle running). Let us know if this info. was helpful and if it fixed your vehicle.

Thank you
Joe T.

I've adjusted the valves per the GM repair guide and I now have compression in every cylinder! I've put it all together but will not try to start it until the distributor arrives. Hopefully tomorrow! I believe it will start now as it is cranking more freely and have good compression in all cylinders.
I'll let you know.
Thanks to everyone for the help, it's much appreciated!
Carl P.

You are welcome, DUFFDIVER is one of our newest experts, he is quickly shaping up to be one of our best!

I had to go out of town until Thursday. I had bought many new parts during the rebuild, except for the distributor! (My memory must be fading as I get older)!! Anyway, it will be waiting there when I get home. I mentioned that I checked after re-adjusting the valves that I had good compression so I'm sure it will start and run great. I'll follow up when I'm done.

Thank you look forward to hear from you.

I knew I should have looked at the new distributor that was delivered before I went out of town. It was for a 1980's Chevrolet! anyway, using the old distributor and guessing on timing, I turned the key and it fired right up!!! No ticking, knocking or backfiring! It sounds like new! Only issue I have is that when I replaced the timing chain, I probably should have dropped the oil pan so that I could have put a lot of gasket sealant where they butt up against each other, because I have an oil leak there (Dammit)! I tried spraying some sealant there but no dice! I'm gonna pull off the fan again so I can get a closer look at the cover to make sure the leak is in fact there. I torqued the timing chain cover to GM specs so that should not be an issue. I am getting a code for the crank position sensor, but I believe that is because the timing is out. It does drive great, though. I need to take it to a garage, because my scanner does not have the Cam retard option, so they will need to set the timing.
Thank you everyone for your help, It was much appreciated.
Carl P

Nice work, we are here to help, please use 2CarPros anytime.

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Cheers, Ken

My 99 Yukon has trouble starting. Doesn't matter time, temperature, time since last started. Once it is running, it runs great!
Items replaced so far: throttle positioning sensor, coil, rotor, dist cap, spark plugs.
most of the time manipulating the gas pedal will help it start. But sometimes it won't start at all. Wait a few hours and it starts right up. I am lost and will appreciate all help.

it could be the fuel pump, sounds like a 92 gmc safari van i had to fix for a friend

Yeah, guess that I forgot to list that. New fuel pump too.

dont you hate the parts throwing game??? it damn sure aint cheap. have a crank sensor on that truck?

Don't know, I am sure it does. You think this could be the problem? I'll check into it.

ok, I believe that your right on the fuel pressure regulator. Problem is that I couldn't figure out where it is. Looked all around the manifold by the fuel rails and couldn't find anything. Anyone where to look for this thing and maybe some tips on replacing it?

Thanks

1999 GMC Yukon 5.7 2WD intermittently will not start. After a few hours of sitting it starts again like nothing was wrong. It may perform fine for days, weeks, and months and then fail again only to work again after sitting for hours with no worked performed. The engine turns over just fine but is not getting fuel. In the beginning I changed the fuel pump (three times). But as I changed the fuel pump each time it checked out fine. I have checked all the fuses and they are good. I have changed and checked the fuel pump relay and it is good. Using a wiring diagram I have seen the next component to check that controls the fuel pump is the Vehicle Control Module (VCM). The way I read the wiring diagram I should be able to apply 12V to the 87A socket on the relay board and start the fuel pump prime, is that correct? Am I on the right track? I see literally thousands of post about this issue with 90 model GMCs but have not seen a satisfactory solution.

I am experiencing a similar problem to yours. The truck starts immediately when cold, runs great. Occassionally (every couple of days) the car will fail to start when hot. Allowing 2-4 hours cooldown, it will start right up. Any suggestions? Could this be a fuel pump issue; or would it just stop altogether?

did you change the connector at the fuel pump module??

Roy

Yes I changed it when I changed the fuel pumps.

Can I get another answer please?

How do you know that you're not getting sufficient fuel. What is the fuel pressure reading when this happens?

Engine Mechanical problem
1999 GMC Yukon Two Wheel Drive Automatic 175000 miles

I have already changed the fuel pump fuel filter and the fuel senser under the hood sometimes it cranks and my run fine for a while and the next time you go to start it all it will do is turn over and will not start.

Next time it refuses to start do below to determine what's causing it and get back with some results we start here.

The car will not start and the fuel pump primer is not coming on. I can normally hear the fuel pump primer come on when I turn the ignition key to the on position but now it is silent.

That's what I thought. You need to use a fuel pressure gauge.

Not sure I am following you, the car will not start, therefore there is not fuel pressure, the guage will reflect 0, will it not? I need to know what is stopping the electrical current from getting to the fuel pump. I can apply 12v straight to the pump and it turns, the fuel pump relay is good, what stops the signal to the fuel pump relay?

When I turn the key the engine turns over, but that's it.

I've changed the plugs & wires, and the Fuel pump relay.

I've sprayed the the throttle body with starter fluid, and

still nothing.

Some-one told me there may be an issue with a "fuel shut

off switch. The problem is, I don't know where that is

located in my truck.

I've sprayed the the throttle body with starter fluid, and

still nothing.

If you had spark it will fire up -lets do the ignition system.

Disconnect a sparkplug wire or 2 and ground it to the engine -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,distributor pick-up coil, ignition control module, cam and crank sensors-

You don't know that you don't have any fuel pressure. You haven't checked it.

in the engine compartment fuse box check ign and ecm fuses if no power have easy fix email [email protected]

For conversation sake, let's say the fuel pressure is 66 lbs at 1200 rpm. What could be telling the fuel pump relay to not engage the primer when the ignition key is turned on? Are there sensors that feed a signal to the VCM or is it a bad VCM?

I'm sorry, I don't work that way. I'll let someone else deal with this if they choose to.

The fuel pump relay is not engaging at the turn of the key. There is no audible click and the fuel pump itself doesn't come on. When I test the fuel pump relay it works fine, I replace it with a new one and it still doesn't engage. I simply want to know what component of the vehicle sends the signal to the fuel pump relay to engage the fuel pump primer when the ignition is turned on to start the car?

i was backing out of my driveway today and it stalled and now it wont start, there is also no electricity getting to any part of the car. i have charged the battery a while.

My 96 Yukon did this right after I bought it, pulled up to a gas station and it died and I mean dead. It would not do a thing. The negative battery terminal was loose and caused my problem. Check your cables first.

Thank you. So as I read this schematic, the dark green/white wire, at pin 85,coming from the VCM should send an electric signal to the fuel pump relay for 5 seconds when the ignition key is turned on, which sends a signal to pin 87A activating the fuel pump primer connector, then that current stops, the relay flips the other way, activating pin 30 and the current from the orange wire coming from the Underhood fuse block passes through the fuel pump relay to energize the pump during normal operation of the engine. And pin 86 is to a ground. Is that how you see it?

I will be having no further involvement in this question.