1998 GMC Suburban Problems!!!

Just wanted to start off by saying hi!! Im a new member to this website and to a GMC Product!!! Previously I own Fords!!! Which I still on A 5.0 as a daily driver!!

Oh so I just bought this Suburban a few weeks ago and and having problems with it!!

First the check engine light is on!!
So I took it to AutoZone to get the codes ran and here are the codes it pulled up

P0327 Knock Sensor Condition

P0300 Cylinder Misfire

P0172 Fuel Trim Bank

So I did a tune up on the Burb!! Plugs wires cap and roter!! Still at idle feels rough!!

I have drivin it 1000 miles so far!! As I took it on vacation!! Justwhen its idling it has a little vibration coming from it!!

It is also hard to start I usually hold the kep for abou 8-9 seconds weighting for it to start and when it does it spits and putters!! So any help will be very helpful!!

Thanks also I smell Coolant and Noticed my Coolant resorvoir is going down slowly!! But I dont know where its comeing from!!

Thanks thomas

Now my suburban will not start at all!!! Thanks for all your replys!!


After reading all of these posts Im confused!! Im not getting no fuel!! Its either Fuel Pump, REGULATOR, Or Spider system RELAY is good!! Fuel Filter is Brand new also!!

If I turn the key on and Press the fuel valve on the engine should gas spray out or should it just come out a little but at first and then no gas comes out at all!!

I also noticed that My pump is not making the loud noise it was making last week!! Now it want start at all only if I put gas in the Carb,!!

Doz:banghead:

Sounds like a bad fuel pump. Check for pressure at the rail, needs 60-65.

Ok changed the fuel pump after only getting 10psi out of the shrader valve!! After new pump in the psi is 65psi!!! It is running and the SES light went off this morning but now it came back on so i guess im drive it till it breaks down again!!

Doz

Man sorry to hear you are getting your chops busted with your Suburban! I have a 99 and I have a love/hate relationship with it. The missing coolant sounds like the infamous intake manifold gasket leak that could be related to the misfire codes you are getting. This is a notorious problem on these engines--it is not a matter of if, but when the gasket is going out. Mine went out at 65,000 miles--I paid someone to fix it though--did not have time to tackle myself. This is a pretty good site for information and another site I have found and use all the time is the one at chevytalk. Everyone recommends replacing the factory gasket with a Fel-Pro brand--which is what I did. There is tons of information on the net related to this.

I had to replace my transmission at 60,000, intake manifold at 65,000. Now my a/c compressor is slinging out oil and Freon (77,000 miles)! It will need replacement shortly. I guess the fuel pump is next :( I have followed the service schedule to the letter and take really good care of my Suburban. It is great on a trip though.

Good luck and keep us posted on what you find out.

Mitch

Doz: Need to know what engine is in your Sub. Try this: disconnect the NEG Batt cable for 15-20 mins. This will reset the VCM. If the SES light comes back on after that have it rescanned for codes and post back the DTC code numbers. You could have multiple problems. As far as the coolant issue, it's probably intake gaskets. Coolant into the intake can foul plugs and maybe O2 sensors. The knock sensor???..............Steve

Sorry its been awhile ive been dealing with more problems with my mustang right now too!! Damn Alternator!!!

Anyways I have a 5.7 Vortec in my Burb!! I smell coolant bad!! And its missfiring on multiple cylinders!! Than the FUEL BANK 1 and Fuel Bank 2 Are coming on together!!

I cannot remember the codes exact but Those were the THree!!

So Intake gasket can be making the burn misfire!! Ive done a tuneup with plugs wires cap roter Fuel filter air filter and Fuel Pump!!

Please HELP A BROKE MAN IN TEXAS!!

Doz

We need the codes for any advice.

Ok here are the codes!!! I FOUND THE PAPERS!!!!

P0172 Fuel Trim Bank One Condition
p0175 Fuel Trim Bank TWO Condition
p0300 Cylinder Missfire Random Cylinders


WILL A LEAKING INAKE MANIFOLD GASKET CAUSE THESE PROBLEMS!!!

Also!! My rapid Leak down is while im holding the RETURN LINE TO THE FUEL TANK!!! I Just put a brand new fuel pump in there!! So I know its good!! WHen I start the burn up!! It has 62-64psi and then when its running it goes down to like 57 and then when I turn it off it goes down straight to 0 withing minutes!!

So what do yall think!! PLEASE HELP!!

Thomas

Could be a bad fuel pressure regulator or leaking injector.

//2000CAYukon

I found your post and to respond from PM.
As 2000CAYukon said could be regulator or injector leak down.
Also One other thing the fuel pump has a check ball that can cause fuel pressure leak off.
With return line pinched or plugged.
pressure should jump to 75-85 lbs if pump is good.
Now on next test with return line still pinched.
Prime up fuel pressure and the quickly pinch off the fuel pump feed/pressure line.
If pressure holds with fed line pinched off it is leaking pressure back threw fuel pump.
If it still drops fast with pressure line and return line pinched off.
You need to pull upper cover off of injectors unit and have a look in there for a fuel pressure regulator leak.
After cover is off hook the fuel lines back up and prime up fuel pressure and look for the leak.
Good luck
MT
MT

Ok will try tonight to check the run off and the fuel pressure!!

Will a leaking intake gasket cause fuel problems!! Please help!!

Thanks thomas

Ok will try tonight to check the run off and the fuel pressure!!

Will a leaking intake gasket cause fuel problems!! Please help!!

Thanks thomas

Depends on the leak.
What or how it is leaking.
But it will not cause a leak down or low fuel pressure.
MT

Ok had the FPR changed out and a fitting on the upper intake that was rusted out causing it to leak coolant!! Put pressure test on my System and the Intake gaskets were not leaking thank god!! So new fitting and FPR and fuel pump now my BURB runs like a champ!!!

Thanks for yalls Help!!
DOZ

Good job DOZ and thanks for posting back from all of us...............Steve