NEED HELP Crank but No start

[Richard_Meyer]

Hi there.

I got a 2005 gmc envoy 4.2L from a coworker. It was in limp mode when I got it, but started all the time.

I had to splice a few wires on the wiring harness, and MAP sensor to get it out of limp mode.

Once I did that, it ran great for one or two times, where I had no issues. Then, I got a p0302 code for cylinder 2.

I got it to my driveway and it didn't want to start anymore.

I got a new coil for #2 and swapped out all spark plugs with iridium 41-103 ac delco from oreillys.

It would just crank and crank, but no start at all.

Then when I was about to give up, it cranked and started. I drove it on saturday for about 45 minutes. No CEL, no rough idle or anything. Beautifully.

I got it back to my house, turned it off and came back out about 20 minutes later and it doesn't want to start again. When I checked the scanner, there was a code for p0014.

I did an oil change, because the car was sitting for awhile. Now the code doesn't come up. It doesn't start.


I'm clueless as to where to begin to diagnose it.


If anyone can lend some advice as to where to check next, I'd greatly appreciate it.


Also, some questions...

Can I eliminate the starter as being an issue if it cranks?

Could the battery be an issue if it is old?

Can a fuel pressure test or anything along those lines be done if the start won't actually start?

Do the envoys have any issues with grounding or whatnot that could be an issue?

 

[Mooseman]

Hi and welcome to the Nation.

We do have this thread from our FAQ.

Cranks but won't start

Can I eliminate the starter as being an issue if it cranks?

Yes and likely eliminate the PCM as well since it is working to actuate it. Also can eliminate the neutral start/PRNDL switch as the problem since it cranks.

Could the battery be an issue if it is old?

Probably not if it cranks fast enough. Having it tested or putting it on a charger is never a bad idea though.

Can a fuel pressure test or anything along those lines be done if the start won't actually start?

Definitely. If fuel pressure is good, next would be a spark check.

Do the envoys have any issues with grounding or whatnot that could be an issue?

Yes. My main battery ground wire on the block turned to green pus while replacing the engine mounts but that caused a no crank. The ones to check/clean are on the left lower side of the block.

Check fuel pressure then spark. Go from your results.

 

[Richard_Meyer]

Mooseman,

Thanks for the reply back! I think I'll stop at harbor freight tonight or tomorrow and pick up the testers needed for spark and fuel.

Do you happen to know exactly where to test for fuel? Is it by the FPR?

 

[mrrsm]

If the Vehicle has been sitting for a while...and presents with having "Weird Electrical Problems"... consider giving all of the Under-Hood Engine Harnesses and Plastic Connectors a Good 'Graduated Eye-Ball' Going Over with a Bright Flashlight, Wear an N-95 Face Mask, a pair of M11 Nitrile Gloves and Good Sealing Eye Protection while in such close proximity to avoid inhaling Desiccated Urine, Feces and Saliva of Mice or Rats nesting under the Hood.

The friable, dusty material is VERY Dangerous and known to harbor the deadly HANTA Virus that causes HPS (Hantavirus Pulmonary Syndrome). Avoid using Compressed Air to dislodge Nesting Materials and use only Wet Wipes soaked in Bleach-Water to Kill the dormant HANTA organisms ...which WILL Kill almost 40% of its Victims once infected by contact in the mouth, via open wounds or bites... or via simply breathing in the Contaminated Dust.

Repair all Broken Wiring with Solder and Shrink Tubing and replace damaged Connectors with harness items from the Local Salvage Yard:

Sources of Information on the HANTA Virus and its Vectors via Animals:

About Hantavirus

An overview of hantavirus, how it's spread and how it can be treated.

www.cdc.gov

Hantavirus pulmonary syndrome-Hantavirus pulmonary syndrome - Symptoms & causes - Mayo Clinic

Learn about the rodent-transmitted virus that causes severe — and sometimes fatal — lung disease with flu-like symptoms that can rapidly worsen.

www.mayoclinic.org

Hantavirus pulmonary syndrome - Wikipedia

en.wikipedia.org

 

[Mooseman]

There is no FPR starting in 2005. The fuel testing port is on the fuel rail. Just be VERY CAREFUL to not put any side load pressure on it with the tester as you could crack the rail. Ask me how I know

Hanta virus hysteria aside, do look for some evidence of rodent activity and wiring chewing. They are made with soy after all.

 

[Richard_Meyer]

There is no FPR starting in 2005. The fuel testing port is on the fuel rail. Just be VERY CAREFUL to not put any side load pressure on it with the tester as you could crack the rail. Ask me how I know

Hanta virus hysteria aside, do look for some evidence of rodent activity and wiring chewing. They are made with soy after all.

Sorry i havent been able to update anyone the last few days, between work and family issues.

I did however get a VVT valve for the p0014 code i had. Still didnt fix the issue. I'll add a soldering kit to my grab list from harbor freight.

Define "side load pressure", mooseman. Ive never done any sort of testing to this magnitude before.

 

[budwich]

Before you go too far in "disturbing things", you might try spraying some starting fluid into the intake to see if engine at least tries to run. That will likely point more to a fueling problem if it tries to start.

If it doesn't start with fluid, then that will point towards spark issues and/ or timing.

 

[Mooseman]

Define "side load pressure", mooseman. Ive never done any sort of testing to this magnitude before.

The fuel pressure testing port is in a bad position where a bracket is in the way. The pressure tester's screw on connector and its hose touches this bracket and puts sideways pressure on the port. The bracket makes it difficult to get the connector on it.

@budwich 's suggestion above is a good one to see if it's a fuelling or ignition issue before going down the rabbit hole.

 

[c good]

Before you go too far in "disturbing things", you might try spraying some starting fluid into the intake to see if engine at least tries to run. That will likely point more to a fueling problem if it tries to start.

If it doesn't start with fluid, then that will point towards spark issues and/ or timing.

Do this next.

 

[Richard_Meyer]

Hi everyone. Just an update.

This morning, i had a coworker come through to look at it, and i didnt hear my pump click. So, i moved the A/C relay over and swapped with the fuel pump, and it kicked on! The car ran until i turned it off. Worked two or three more times, and then wouldnt start.

Proceeded to swap another relay with it, and it started up again. All relays are working as intended. A/C still worked, etc while it was running.

Im starting to believe theres something wrong with the fuse box, preferably underneath. If it doesnt start, i just have to swap a fuse around and it'll kick in.

Does anyone know if the fuse box is easy to replace or is it difficult? Whats underneath? Should i still take it to a shop?

Thanks,

Rich

 

[budwich]

It is more than likely that the relay socket on the fuse box is "worn". Pull the relay and slight "twist" / "spiral" the pin on the relay to aid their contact in the socket.