Truck Broke down last night.

[Salmon Stalker]

It started a couple of days ago I felt like my truck (1996 GMC 4x4 Sierra 5.7 ltr) started running a little rough. It felt like I was driving with the e-brake on when I accelerated.

 

Then last night I got a call from my wife who had the truck and she said it died and wouldn't re-start. So I got there and she explained that the truck started to sputter and then threw up a check guages (not a check engine) light and then died. She tried to re-start it and it just cranked and cranked. I did a couple of things. I first tried some starting fluid thinking maybe we weren't getting gas (not sure if that is bad for fuel injection or not) but that didn't work. If I worked the gas pedal it did seem like it wanted to start. Then I check the coil for spark. Yep plenty there. Then then when I disconnected one of the plug wires to test it the d**n thing started. Well I figured I won't press my luck I drove it home to investigate further there.

 

As I drove home the truck sounded horrible and bucked and sputtered all the way whenever I accelerated. The sound was like a car with a hole in the muffler or something. I also started smelling an odor like rotton eggs. This got me thinking catalytic converter. When I got home (3 miles away) I looked under the truck and found the outlet of my catalytic converter looked like a branding iron as it was bright orange and smoking. My muffler looked the same.....

 

So I'm thinking a couple of possibilities and am looking for other opinions before I take it up to have the computer scanned.

 

1. Replace catalytic converter- Does it really go bad that fast?

2. Could the fuel mixture be too rich. If so that would be computer or sensor problmes I'm thinking.

3. What else could it be? Any Ideas.

 

Thanks for any help you can offer....

 

Chad

[Bish]

It started a couple of days ago I felt like my truck (1996 GMC 4x4 Sierra 5.7 ltr) started running a little rough.  It felt like I was driving with the e-brake on when I accelerated. 

 

Then last night I got a call from my wife who had the truck and she said it died and wouldn't re-start.  So I got there and she explained that the truck started to sputter and then threw up a check guages (not a check engine) light and then died.  She tried to re-start it and it just cranked and cranked.  I did a couple of things.  I first tried some starting fluid thinking maybe we weren't getting gas (not sure if that is bad for fuel injection or not) but that didn't work.  If I worked the gas pedal it did seem like it wanted to start.  Then I check the coil for spark. Yep plenty there.  Then then when I disconnected one of the plug wires to test it the d**n thing started.  Well I figured I won't press my luck I drove it home to investigate further there.

 

As I drove home the truck sounded horrible and bucked and sputtered all the way whenever I accelerated.  The sound was like a car with a hole in the muffler or something.  I also started smelling an odor like rotton eggs.  This got me thinking catalytic converter.  When I got home (3 miles away) I looked under the truck and found the outlet of my catalytic converter looked like a branding iron as it was bright orange and smoking.  My muffler looked the same.....

 

So I'm  thinking a couple of possibilities and am looking for other opinions before I take it up to have the computer scanned. 

 

1.  Replace catalytic converter- Does it really go bad that fast?

2.  Could the fuel mixture be too rich. If so that would be computer or sensor problmes I'm thinking.

3.  What else  could it be?  Any Ideas.

 

Thanks for any help you can offer....

 

Chad

 

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Mileage would help.

 

IMO, it could be a few things. First off, if you have access to a code reader, scan it and post the code. Similar symptom to when my fuel pump went minus the cherry red cat. Also could be a plugged fuel filter or air filter. If around 80-100K, O2 sensors could be going bad. Plugs and wires if they have mileage on them.

 

1> I've got 154K on my cats and they are still going strong.

 

2> Yes, it sounds like it is running rich as evident by the super hot exhaust.

[bronyaur]

Just a thought, but a cracked distributor cap will do exactly what you are describing. The resulting misfire causes unburned gas to go into the exhaust which plugs up the cat. However, I would expect a random misfire code followed by a low cat code, maybe a few days later. I know it doesn't explain why it started after you removed the plug wire. Maybe after it cooled the crack in the cap wasn't as significant. Just thinking out loud.

[cmadz71]

I second the distributor cap. On my 1998 K1500, I had this happen twice and it was the distributor cap both times. The first time the truck would start but run rough and backfire. It was throwing a code about misfire. I replaced the cap and it ran just fine. My cats went bad after this because it was dumping unburnt fuel into the exhaust system. The second time the cap went bad was when I had the truck sitting trying to sell it. It would not start but would want to start if you gave it more gas. I finally remembered the first time and replace the distributor cap. Everything was fine after that. I would try the distributor cap first especially since you said you gave it starting fluid and nothing happened.

[Salmon Stalker]

The distributor was new when I did my intake manifold last December. I checked it anyway and it was fine. Not cracked or worn.....

 

After checking the d**n thing won't start so I'm still not sure. Maybe I need to go back to the starting fluid so I can get it running to go down the street to the mechanic.......

 

I don't have a clue.... Would a clogged muffler make it not start? Would the electronic controls cause the injectors to inject more fuel due to a clogged exhaust... I'm just wondering if I'm flooding the thing due to the richer mixture....

[BRZ71]

The distributor was new when I did my intake manifold last December.  I checked it anyway and it was fine.  Not cracked or worn.....

 

After checking the d**n thing won't start so I'm still not sure.  Maybe I need to go back to the starting fluid so I can get it running to go down the street to the mechanic.......

 

I don't have a clue.... Would a clogged muffler make it not start?  Would the electronic controls cause the injectors to inject more fuel due to a clogged exhaust... I'm just wondering if I'm flooding the thing due to the richer mixture....

 

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The rotton egg smell was probably the unburnt gass from the cylinder you pulled the plug on. It was probably burning it off in the cat and that is what caused the cat to get so hot. Sounds like the fuel pump to me. Have you checked your fuel filter? Also get a fuel pressure guage and put it on the fuel rails and see what your fuel pressure is after you check and or change the fuel filter.

[Salmon Stalker]

BRZ71 .... That's pretty funny that you said fuel pump/fuel filter. A buddy just came over and brought a friend that is a mechanic. He didn't have his code reader with him but said the same thing. In fact, he said he's 100% sure it's the fuel pump.... Well I'm not that sure but it makes sense....

 

He said that he thinks that the reason I'm smelling gas is that I am flooding it. Without sufficient pressure (he said 61lbs) the gas is trickling in the cylinder not enough to fire and so it is accumulating and flooding it. Does that make sense? I also pulled one of the plugs and it smelled so much like fuel it seemed that it was damp with fuel....

 

I guess I'll be testing the fuel pressure tomorrow after work and replacing a fuel filter.

 

Chad

[BRZ71]

BRZ71 .... That's pretty funny that you said fuel pump/fuel filter.  A buddy just came over and brought a friend that is a mechanic.  He didn't have his code reader with him but said the same thing.  In fact, he said he's 100% sure it's the fuel pump.... Well I'm not that sure but it makes sense....

 

He said that he thinks that the reason I'm smelling gas is that I am flooding it.  Without sufficient pressure (he said 61lbs) the gas is trickling in the cylinder not enough to fire and so it is accumulating and flooding it. Does that make sense?  I also pulled one of the plugs and it smelled so much like fuel it seemed that it was damp with fuel....

 

I guess I'll be testing the fuel pressure tomorrow after work and replacing a fuel filter.

 

Chad

 

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Not that funny, it seems to be showing up more and more. Read through the last few months of posts, you will see what I mean. I hope mine isn't next!!!! They are not cheap either. I don't know off hand what the pressure should be, but I know it has been mentioned several times in some past posts.

 

Everyone tells me to keep my tank at least 1/2 full to keep the pump cool, has anyone else heard that, and is there really any validity to it helping the pump last longer?

[Salmon Stalker]

I didn't mean that the problem was funny. I meant that it was funny that I logged onto the site to ask about the fuel pump and you had already reccomended that I look at it.... I appreciate the input on that....Of course you know I just put 20 gallons in the tank 2 days ago. Let's see 20 gallons at 8 lbs per gallon.... d**n. That's gonna be heavy if it has to be replaced.......

[Mark_in_Tulsa]

I didn't mean that the problem was funny.  I meant that it was funny that I logged onto the site to ask about the fuel pump and you had already reccomended that I look at it....  I appreciate the input on that....Of course you know I just put 20 gallons in the tank 2 days ago.  Let's see 20 gallons at 8 lbs per gallon.... d**n.  That's gonna be heavy if it has to be replaced.......

 

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Well the good news is that Gasoline weighs 6 lbs per gallon.

[Wingnut]

Not if you do it the easy way.

 

Don't drop the tank. Take the bed off the truck and fix it without removing the tank. Just a few bolts, the tail light harness, fuel filler neck, and a couple of strapping young lads to lift it off there. Easy-peasy-japaneasy. You'll be sitting comfortably on the framrails with your beer less than 2 feet away instead of laying around in last weeks oil change mishap for 4 hours. not to mention that one pebble that always jams right into your shoulder blade and never goes away no matter how many times you sweep the floor.

 

It's only about 147 times easier than dropping the tank.

[willfxp]

Not if you do it the easy way.

 

Don't drop the tank. Take the bed off the truck and fix it without removing the tank. Just a few bolts, the tail light harness, fuel filler neck, and a couple of strapping young lads to lift it off there. Easy-peasy-japaneasy. You'll be sitting comfortably on the framrails with your beer less than 2 feet away instead of laying around in last weeks oil change mishap for 4 hours. not to mention that one pebble that always jams right into your shoulder blade and never goes away no matter how many times you sweep the floor.

 

It's only about 147 times easier than dropping the tank.

 

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Wow, if it's that easy, I wonder if it's a good idea just to replace it as preventitive maintenance? I wonder how much fuel pumps cost...

[Wingnut]

I won't touch mine until it dies. They're a couple hundred bucks. And it's an all afternoon job if you've never done it.

 

Second time I did it, it took about 3-4 hours.

[Salmon Stalker]

...Second time I did it, it took about 3-4 hours.

 

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Please tell me that the 2nd time was on a different truck than the first.....

[Wingnut]

Yes it was.

 

The fuel pumps on both my trucks are the originals. I've only does this job on friends trucks.