00 Yukon turns over but won't start

[saltygq]

Hi all,

Went out to start my 2000 Yukon XL 4x4 today and it would just turn over but not start. It doesn't attempt to start, just turn over. The fuel pump is about a year old and you can hear the pump turn on when you turn the key over. I also was able to check one of the coil packs and I do have spark. That's about all I could check before I had to go into work.

Is there a common issue with the truck that it would just not start, relay or something?

When I get home I plan on pulling the plugs to see if I'm getting gas in there.

Any other ideas, any help would be great with the limited information I supplied.

Thanks,

-G

 

[cowboyzr2]

You don't happen to have a flashing security light do you?

 

[saltygq]

You don't happen to have a flashing security light do you?

No flashing sec light, I have stock alarm with no remote start too. When I leave the key in the on position the check engine light stays on but I think it's suppose to.

Kind of drivng me crazy a little bit, I changed out the fuel pump about 2 years ago and had to replace it when it went bad about a year ago. The check engine light was on about a year ago, code stated it was fuel pump. I replaced it and it was fine.

Yesterday no issue no check engine light, not thinking it can't be the pump again but not sure.

I heard you can check the full pressure with a gauge but not sure where to check that from. My thinking would be that if that is ok then the pump would be fine. Autozone have that for rent?

 

[electro]

No flashing sec light, I have stock alarm with no remote start too. When I leave the key in the on position the check engine light stays on but I think it's suppose to.

Kind of drivng me crazy a little bit, I changed out the fuel pump about 2 years ago and had to replace it when it went bad about a year ago. The check engine light was on about a year ago, code stated it was fuel pump. I replaced it and it was fine.

Yesterday no issue no check engine light, not thinking it can't be the pump again but not sure.

I heard you can check the full pressure with a gauge but not sure where to check that from. My thinking would be that if that is ok then the pump would be fine. Autozone have that for rent?

Hey man...You can check fuel pressure on the fuel line at the back of the engine pretty sure.

You should get yourself a Haynes manual or whatever your local parts store has.

Also...You can pull off the fuel SUPPLY line at the back top of the engine using a fuel line disconnect tool. Have someone prime pump and if pumps good...You should see fuel poor out a reasonably good rate. Just get a good rag under there before you do it to absorb fuel or a cup or something.

Heres what the tool looks like. That was just a random google image search:http://www.google.ca/url?sa=i&rct=j...b49YCpUcBQ-i2kW6NX-uT-QA&ust=1363218746697501

Probably quite a bit cheaper than a fuel pressure gauge but not as proper as the fuel pressure gauge.

 

[saltygq]

Thanks Ryan,

So here is the update...

After work last night came home and the truck started right up. Check engine light was on. I took it to autozone and had them run the test. Came back with a random cycinder misfire. Car was running ok on the way to Autozone but on the way back it was running rough. It didn't stall but was running rough and the check engine light started flashing. I nursed it home and while it was running I disconnected the maf sensor, it died and then the egr, no effect.

Took the truck back today to autozone with the flashing light and I have several codes now.

P0304 - number 4 cylinder misfire
P0354 - Ignition coil primary circuit
P0300 - Random cylinder misfire
P0405 - EGR valve, maybe from when i disconected while running
P0102 - MAF sensor, I'm sure from me when i disconnected it.

Wondering if bad gas could cause all of this or not. I will be picking up a new coil and replacing #4. And I picked up a new set of plugs, might check those first to confirm that we have an issue on cylinder 4.

Any thing else I could be missing?

Thanks,

---------- Post added at 07:57 PM ---------- Previous post was at 06:38 PM ----------

quick update...

Changed out coil pack for #4 cylinder and no change, actually a little change because it feels like it's running rougher now.

I will be pulling the plugs to see how they look, maybe it might point me in the right direction.

Any ideas just let me know.

 

[electro]

When was the last time you changed plugs and wires. If you can, just replace all plugs and wires. That's always a healthy engine decision. Do you have a nice clean air filter? If you dont know... buy a new one. Do you have a digital multi meter? If not buy one. Than measure the resistance of each one of your coils. Just the coils and this will determine condition of them. I don't know the ohms of resistance your coils should have but you can either find out or just compare them against each other. Also I think you should get a fuel pressure gauge and measure your fuel pressure at the rail. Perhaps next time instead of buying new coil just switch two around and see if you still produce the code. Your current plugs may just need a little tlc. Make sure they are gapped to your trucks specifications. Maybe a fuel filter two if you don't know when it was replaced last.

Sounds like a good tune-up is in order.

 

[saltygq]

Little update..

The check engine light went away the other day and the car was running fine. Yesterday the light came on in the morning, started flashing and truck was running rough. Next time I started the truck the check engine light was on but running fine. This morning went to start up the truck and it woudl just turn over but not fire up. Waited about an hour or two and it started up fine with no CEL.

I would bring it in to a shop and have them look at it but right now, no CEL and it runs and starts fine.

Do you think the fuel pump could be going bad, does't that make sense. I would think that once its bad its bad. No coming back.

Any other ideas would be great. TY

---------- Post added at 01:36 PM ---------- Previous post was at 01:35 PM ----------

When was the last time you changed plugs and wires. If you can, just replace all plugs and wires. That's always a healthy engine decision. Do you have a nice clean air filter? If you dont know... buy a new one. Do you have a digital multi meter? If not buy one. Than measure the resistance of each one of your coils. Just the coils and this will determine condition of them. I don't know the ohms of resistance your coils should have but you can either find out or just compare them against each other. Also I think you should get a fuel pressure gauge and measure your fuel pressure at the rail. Perhaps next time instead of buying new coil just switch two around and see if you still produce the code. Your current plugs may just need a little tlc. Make sure they are gapped to your trucks specifications. Maybe a fuel filter two if you don't know when it was replaced last.

Sounds like a good tune-up is in order.

Thanks I changed out the plugs and air filter, wires looked fine but I will test them when I test the coil packs today. Fuel filter was changed about a year ago. I can see if it just didnt start again but this somedays it starts and somedays it doesn't is driving me crazy.

Thanks again for the help.

 

[saltygq]

Little update,

I took the truck to a local Tuffy and they completed a couple tests on the truck while it was running without the CEL on.

They pulled up the same codes as before but said it didn’t make sense why it wouldn't start. Same thing I was thinking. They tested the fuel pressure and that was perfect, key on pos car off, key on pos car running, and key in off pos car off. I think he said about 50psi.

He did say there may be a vac leak on the intake manifold gasket but doesn’t see why it wouldn't start.

I drive the beast home and park it, come out the next day and it won't start. The only weird thing is that the car is under 1/4 tank of gas and if I remember correctly that's been the case for each time it wouldn't start. I looked at another post and someone was saying they have the same issue. Either way I may go put some gas in just to rule that out.

So not starting, turns over great, I’m getting spark. Should I be able to pull one of the plugs and see or smell gas in there?

I mean if it turns over and I'm getting spark what else can stop it from starting if gas is in the cylinder?

What would be the best way for me to check that gas is actually getting in the cylinder? Or if I'm looking at the wrong thing please point me in the right direction.

Thanks in advance for your help

-G

 

[saltygq]

So ends up the fuel pump again, this will be the 3rd one in two years. The first two I purchased from pep boys and this one I purchased online. Truck wasn't starting so I banged on the fuel tank and guess what she started up. Starting to dislike this truck.