2001 suburban starting issues

[p_rubottom]

I bought a burb a few weeks ago for my wife and the kiddos, I've started to do some maintainance on it. It has 130k on it, its developing a starting problem. You have to hit the switch two or three times to get it to fire. I put new plugs & wires on it and its helped a little but still having problems. I'm leaning towards new coil packs, is there a way to test them to figure out if there's a week spark? Or am I looking in the wrong area?

[bighaas79]

check for leaking puel pressure regulator. You don't need coil packs.

[fxdxharley]

Originally Posted by bighaas79

check for leaking puel pressure regulator. You don't need coil packs.

X2 on the regulator. had the same problem on my 2000 6.0L. An easy check is to pull the vacuum line off the reg and if fuel comes out its no good. beware they are about $100 bucks. the reg is on the left side, above the valve cover right where the fuel lines connect.

[p_rubottom]

Thanks guys, i'll check it out tonight and see what i can find out.

[p_rubottom]

Would the regulator cause it to idle a little rough and stutter when accelerating from a stop?

[clinebarger]

Did you check the regulator like previously stated? If no fuel was present in the vacuum port, check the fuel pressure (key-on engine off 55-62 psi). Did you change the fuel filter? Check engine light on?

[p_rubottom]

Originally Posted by clinebarger

Did you check the regulator like previously stated? If no fuel was present in the vacuum port, check the fuel pressure (key-on engine off 55-62 psi). Did you change the fuel filter? Check engine light on?

No fuel was in vacuum port, the check engine did come on today when it started running bad. Autozone scanned it said it was a miss-fire on multiple cylinders. (with new plugs and wires?) I did get a fuel filter, going to install it tomorrow after work.. How do I check fuel pressure on this engine? Also the Autozone employee that scanned it said since the rough idle is throwing the engine off balance that means its an odd number cylinder??? is that correct?

[clinebarger]

Originally Posted by p_rubottom

No fuel was in vacuum port, the check engine did come on today when it started running bad. Autozone scanned it said it was a miss-fire on multiple cylinders. (with new plugs and wires?) I did get a fuel filter, going to install it tomorrow after work.. How do I check fuel pressure on this engine? Also the Autozone employee that scanned it said since the rough idle is throwing the engine off balance that means its an odd number cylinder??? is that correct?

P0300 multiple cylinder misfire? When you say odd number cylinders I think 1-3-5-7 are misfiring?

[truckdude239]

sounds like the intake gaskets are leaking

[p_rubottom]

Originally Posted by clinebarger

P0300 multiple cylinder misfire? When you say odd number cylinders I think 1-3-5-7 are misfiring?

Yes, thats correct.

[p_rubottom]

Originally Posted by truckdude239

sounds like the intake gaskets are leaking

Thats what i'm afraid of, after reading more into higher mileage 5.3's. I am going to try spraying starter fluid along the intake tonight and see if i find anything there.

[p_rubottom]

So tonight I changed the fuel filter and sprayed around the intake with starter fluid. I noticed no changes in the rpm's when spraying the intake and no changes in the rough acceleration with the fuel filter change. Im really leaning towards ignition source??? Any other ideas on trouble shooting?

[clinebarger]

Originally Posted by p_rubottom

So tonight I changed the fuel filter and sprayed around the intake with starter fluid. I noticed no changes in the rpm's when spraying the intake and no changes in the rough acceleration with the fuel filter change. Im really leaning towards ignition source??? Any other ideas on trouble shooting?

All the misfires on one side make me think catalytic converter. Gen III engines have bulletproof ignition systems, I havnt seen a coil pack go bad yet, Plugs/wires thats it. The hard start sounds fuel related though.

[bwood]

It might be worth a few bucks to take it to a shop who can look at live data with a scanner. There was a member on here not to long ago mentioning the same symptoms, but he did have a few more codes. Here is a link:

http://67-72chevytrucks.com/vboard/s...d.php?t=399506

Testing fuel pressure will require a fuel pressure test gauge, ($30-40) at the parts store). Locate a schrader connection on the fuel rail and connect gauge. Turn the key on and check the pressure, then give it a few minutes and see how much it bleeds down. Then start it, check pressure again. Post your findings.

[p_rubottom]

Originally Posted by clinebarger

All the misfires on one side make me think catalytic converter. Gen III engines have bulletproof ignition systems, I havnt seen a coil pack go bad yet, Plugs/wires thats it. The hard start sounds fuel related though.

After reading BWOODS post on the yukon it sounds like a cat problem to me too. I think I'm going to run it to shop for a quick scan and have the cat's and O2 sensors looked at. Thanks for the help guys's i'll post as soon as I know something.

[Rudy67chevy]

Originally Posted by fxdxharley

X2 on the regulator. had the same problem on my 2000 6.0L. An easy check is to pull the vacuum line off the reg and if fuel comes out its no good. beware they are about $100 bucks. the reg is on the left side, above the valve cover right where the fuel lines connect.

the regulator cost me $135 at the dealer. autozone or kragen regulators didn't fit right

[bighaas79]

Originally Posted by clinebarger

All the misfires on one side make me think catalytic converter. Gen III engines have bulletproof ignition systems, I havnt seen a coil pack go bad yet, Plugs/wires thats it. The hard start sounds fuel related though.

I have to agree with you on the ignition system part, I also have yet to see a coil go bad on one of these engines. Fuel or air/fuel mixture issues are a more likely culprit here.

[truckdude239]

Could also be a fuel pump going bad

[p_rubottom]

Originally Posted by truckdude239

Could also be a fuel pump going bad

Thats what i was just thinking. I pulled the left bank o2 censer and disconnected the electrical but i still had the shuttering as the rpm's climbed. I might grab a fuel pressure gauge before i take it to the shop Thursday to check that too.

[p_rubottom]

I replaced the fuel reg valve ($50 at autozone) and checked the fuel pressure key on engine off it hit about 55 then died back to about 10... I'm going to replace the fuel pump.

[p_rubottom]

Alright guys so i figured out the problem today. When I replaced the plugs and wires I bought the E3 spark plugs. Thought they were suppose to be the most "efficient" plugs available.... Well after the fuel press reg, fuel filter, fuel pump i bought AC Delco plugs just to see if thats what it was, and its was!!!! On the plus side i have all new fuel components due to when i read the pressure it was low and not holding 55+ psi. But has anyone used these E3 plugs? I don't know what the deal was but the burb did not like em! Thanks for the help again guys.

[clinebarger]

Originally Posted by p_rubottom

Alright guys so i figured out the problem today. When I replaced the plugs and wires I bought the E3 spark plugs. Thought they were suppose to be the most "efficient" plugs available.... Well after the fuel press reg, fuel filter, fuel pump i bought AC Delco plugs just to see if thats what it was, and its was!!!! On the plus side i have all new fuel components due to when i read the pressure it was low and not holding 55+ psi. But has anyone used these E3 plugs? I don't know what the deal was but the burb did not like em! Thanks for the help again guys.

They have a new sales gimic spark plug? Will they ever give up on that Remember the Splitfires & Bocsh platnium+4, & +2s, What a joke!

After you installed the fuel pump it was still hard to start? Or the plugs fixed everything? Or just the misfires?

[bwood]

I have always had the best performance with the stock AC plugs. I'm with Cline on the "gimic" value of the E3, Bosch stuff. If they were that great, the OEM would have incorporated a similar design to begin with. Honestly Bosch is about as cheap as they get. When I sold them at Oreilly's, they were the cheapest regular platinum we sold.

[p_rubottom]

Originally Posted by clinebarger

They have a new sales gimic spark plug? Will they ever give up on that Remember the Splitfires & Bocsh platnium+4, & +2s, What a joke!

After you installed the fuel pump it was still hard to start? Or the plugs fixed everything? Or just the misfires?

The pump fixed the start delay so it starts up on the first hit of the key and the delco plugs fixed the rough idle/accelerating.