Need Help from GMC/Chevy Truck guys

[krt400ex]

ok, so i have a '97 GMC sierra 1500 with the small block 350 Vortec. lately the engine has not been running quite right. i know it has a small header leak which i will be getting new headers for, but it has been really hanging in the top end. once i get past about 3800 RPM it does not pull. i know this is not just the header problem because it does not always do this. it is sometimes. the truck has a 160 degree thermostat in it...dunno if that has any significance. i am thinking maybe an oxygen sensor? sometimes it pings when its doing this...not always. i dont understand it. thanks for the help

Kurt

[bossman525]

check your fuel pressure.

[markk]

that ping is probly a spark knock. I would give the truck a full tune up and first start by running better gas!!!

tune up

(plugs-wires- air filter-fuel filter- trans filter and gasket- and depending on what style ingnition system u have u might have to change cap and rotor)

[yellow400ex05]

sounds like it could be a fuel pressure regulator, or bad gas.

or a mix of both.

Do you let the tank run below half often?

if you do it could cause the fuel pressure regulator to heat up and wear it out.

if you want to kinda check it just turn your key to the on position (don't start it) just put it so that the radio comes on and the gauges like up, then go near the back of the truck, if you hear buzzing it usually mean your Fuel pressure regulator is strong, if you don't hear it it could be on its way out. Also the buzzing usually goes for about like 10 seconds at the most then its stops which is normal.

also give it a tune up if it hasn't had one recently.

[79400ex]

Have the on board computer checked to see if any codes are in

Originally posted by markk
that ping is probly a spark knock. I would give the truck a full tune up and first start by running better gas!!!

tune up

(plugs-wires- air filter-fuel filter- trans filter and gasket- and depending on what style ingnition system u have u might have to change cap and rotor) answer all yur problems sell it and buy a FORD!!

[theTman]

Originally posted by mxcowboy
answer all yur problems sell it and buy a FORD!!


Found
On
Road
Dead

Fix
On
Race
Day

:devil: :devil:

Originally posted by theTman
Found
On
Road
Dead

Fix
On
Race
Day
IM GAY
:devil: :devil:


F**EDIT NO "F" BOMB on BOARDS!**
ROAD
DEMON

[TCracin440ex]

i had a 98 1500 5.7 vortec. these motors are famous for problems. i know i had the intake manifold gasket shift on me a few times these motors are famous for the intake gaskets shifting. you want the answers to your problem go to CHEVY TRUCK WORLD


http://chevytruckworld.tenmagazines.com/



pic of my old 98

http://b0.ac-images.myspacecdn.com/01451/01/90/1451900910_l.jpg

[TCracin440ex]

[QUOTE]Originally posted by mxcowboy
[
dude why do people like you come on these threads to start s? theres always some dumb *** like you that wants to come on a thread like this to be a post whore and say s that dont even pertain to the subject.

so what you like ford...big deal you aint gotta come on this thread with the flaming

[TCracin440ex]

pic of my "new" truck jus for chits and giggles


http://a149.ac-images.myspacecdn.com/images01/69/l_126f92f99048b89d52b30e0e34ec83fc.jpg

[tri5ron]

Kurt,
First thing, change the fuel filter.
(It's the all steel type, and is mounted on the inside of the frame rail, back near the fuel tank).

Then pull the fault codes from the computer.

if you need some info on how to do that, let me know.
I have the Factory/Dealer repair manuals for your truck.
(I have a '97 Suburban 1500, same thing)

[hardkoratvmxr]

do all the tuneup things like said before, plugs, wires, oil air and fuel filters, and dont forget your 02 sensors those are some of the most over looked things

[Hornbreaker]

FORD- Flip over read directions or DROF- Driver returns on foot.

[416exfreak]

Enough with the ford vs chevy crap. Its a losing battle for BOTH sides...

Kurt- check your O2 sensors and give her a good tune up, go fill it up with some GOOD gas, im recomending Shell or BP, and fix your header leak.

I dont know much about chevy's being a Ford guy myself, but I wish you luck in getting it all figured out.:)

[krt400ex]

Originally posted by yellow400ex05
sounds like it could be a fuel pressure regulator, or bad gas.

or a mix of both.

Do you let the tank run below half often?

if you do it could cause the fuel pressure regulator to heat up and wear it out.

if you want to kinda check it just turn your key to the on position (don't start it) just put it so that the radio comes on and the gauges like up, then go near the back of the truck, if you hear buzzing it usually mean your Fuel pressure regulator is strong, if you don't hear it it could be on its way out. Also the buzzing usually goes for about like 10 seconds at the most then its stops which is normal.

also give it a tune up if it hasn't had one recently.


yea that is fine. and i run plus or premium in it. never regular

[krt400ex]

thanks for the responses so far. i will go ahead and try the tuneup i guess. this thing has been bugging me lol. i cannot stand when my stuff is not right and i didnt really know where to start with this thing since i am still new to the car/truck world.

[hskers82]

I had a '97 with the votec 350 and it would hesitate under acceleration and it was the fuel pump not pushing enough psi.The pump still worked it just wasn't running a high enough psi.As someone else noted that motor is notorious for intake gaskets.I had to replace mine and the mechanic said usually every 75,000 miles and it will need replaced.

[krt400ex]

well maybe i should check that then. there is a whistle when i let off the gas...and that was not there either. i figured it was just from the intake and i never noticed it cuz i usually blair my music. the truck just turned 107K yesterday. i bought it with 86K on it. is this gasket easy to do? can i do it myself?

[krt400ex]

so it was low on fuel today and i filled it...and it was running like crap before and running much better after. it still was not the way it was supposed to be but it pulled much stronger. it did still ping in the top end after like 4500RPM though. what do you all think? obviously when the tank is low, it is not getting enough fuel. what would cause this?

[ProspectorJim]

just one more
Fix
Or
Repair
Daily

[TRX450RACER174]

I also had this problem in my 98 when i had it, Replace the fuel filter on the left frame rail that will probably fix the problem, If not then replace the pump but the f/f is a fast fix.

[yellow400ex05]

I suggest signing up to

www.Fullsizechevy.com

and posting in the technical section on the problem/symptom's your having, they are usually pretty quick, also a search will net you a quite a few threads on this already.

I've read top end cleaner such as seafoam or GM top end cleaner could clear it up.

It could be numerous things that cause pinging. The gas octane is NOT the issue since you use higher octane.

Damn dude you really do drive the snot outta the truck lol thats a lot of miles in that amount of time haha.

I started driving mine when it had 121k and now it has 126k lol.

BTW I left his nice piece of rubber after getting in a fight with my brother at 2am, put it half way to the floor started out as 2 tire marks with the posi, went to 1 as i turned due to the weight being off the one tire lol.


http://i34.tinypic.com/311mbnr.jpg

[TCracin440ex]

lame rubber...that nbs chevy of mine has a detroit locker in the rearend and she leaves the prettiest blackmarks ever

[krt400ex]

Originally posted by yellow400ex05
I suggest signing up to

www.Fullsizechevy.com

and posting in the technical section on the problem/symptom's your having, they are usually pretty quick, also a search will net you a quite a few threads on this already.

I've read top end cleaner such as seafoam or GM top end cleaner could clear it up.

It could be numerous things that cause pinging. The gas octane is NOT the issue since you use higher octane.

Damn dude you really do drive the snot outta the truck lol thats a lot of miles in that amount of time haha.

I started driving mine when it had 121k and now it has 126k lol.

BTW I left his nice piece of rubber after getting in a fight with my brother at 2am, put it half way to the floor started out as 2 tire marks with the posi, went to 1 as i turned due to the weight being off the one tire lol.


http://i34.tinypic.com/311mbnr.jpg


i lit mine up saturday night lol. i should go back and take the pics of it. left a decent 11 in a parking lot. buttload of smoke. the tires on there now are soft. and yea, i drive it alot lol. i got it last october.

[krt400ex]

oh and james, the truck pulls till 5200 before it shifts so i wanted to see how it felt.

[krt400ex]

it was the fuel pump. thing started sounding strained and went on me last night. put the new one in and all my problems went away. i did everything but that and things got better, but the problem never got fixed. i guess the pump was just on its way out and wasn't keeping enough psi in the lines or something