rpm's surging at around 30-50 mph! HELP, Is it the Shi@Ty GAS!

[amstaffbair]

I have an o3 h2 with 80 g miles on it . I am having some issues with truck surging in low rpms. Right around 12 to 1500 rpms it starts to bounce up and down. you can feel it terribly. I had a stage 2 jet chip in at one time time and thats when i started to notice it .. ( never notice a power difference with chip in). SO i took chip out and its still doing it!
Its gets better if i run 93 octane. I was wonder if the truck is not liking all the ethonal in this new so called gas our stores are selling??

Anybody have this problem???

ALso what kind of tune up should i do at 80,000 miles??

thanks

Andy

[MONSTERMATT]

there is a recomended fuel service at about 75k i think

[timgco]

You are due for a tune! Your injecters being dirty may have something to so with it. My 03 did this. I paid the dealer for the very expenses service, ut all was better when they were done.

[amstaffbair]

i changed the fuel filter and i am running 93 ans it still does the surging!

I CLEANED THE INJECTORS AS WELL!

[TXSUT]

I CLEANED THE INJECTORS AS WELL!

You cleaned them, or had a mechanic clean them?

[amstaffbair]

well what i meant i used sea foam and some fuel injector cleaner!!
sorry fellas!

[tVan]

i've had this same problem for a while now...i've done and changed everything i can possibly do and still not fixed. going to look at new cars today.

[IRA51]

Try this, change your fuel filter,check your air filter and replace if dirty,if you have a K&N make sure you do not over oil it ,remove all the spark plugs and get a can od GM top engine cleanrt from your local Chevy dealer and use a funnel and a piece of rubber hose and pour it in all cylinders let it sit over night than spin the engine over a few times to force out the remaining fluid ,replace the plugs with new NGK or AC delco plugs of the proper heat range and inspect the plug wires and replace if needed new wires are always a nice touch on a tune up . put in 2 cans of seafoam with a full tank of premium fuel , give the throtle body butterfly a few shots of carb cleaner (both sides open it )to remove some carbon (don't over do it ) start your truck and watch as it smokes like a train .than after 15 min go and drive it like you stole it . after you get down to a 1/4 tank change your oil. you may also want to clean your MAF with some eletrical parts cleaner spray . and don't forget to use anti seize compound on the plug threads (just a very light thin coat ). if that does not cure it you ether have a suspect MAF and you should get it tested B4 you replace it . if you have a MIL (CHECK ENGINE LIGHT ON) SCAN AND READ THE CODE FIRST b4 DOING ANYTHING GOOD LUCK . AND CALL OUT THE OLD GIRL AND LET HER WATCH THE SMOKE SHOW . GOOD LUCK . SOME TIMES A BAD INTAKE MANIFOLD GASKET WILL BE THE CULPRIT .

[OWSI]

You aren't by chance trying to run E85 in it are you? That would definitely mess things up.

[amstaffbair]

just an update! i cleaned my throttle body and cleaned my mass air...


All is good !!!!!:jump: No surging and a much better idle!!!

thanks for the help!!!




andy

[CDiprecision]

I did the same and the surging is now gone too...

[Xotik H3]

Mine did it tonight.

Old threat but a great one.

[Lucky1]

What did you clean your throttle body and mass air with ?

[Xotik H3]

What did you clean your throttle body and mass air with ?

I used Carb cleaner for the throttle body, engine off, not a lot but a spray around the butterfly and wiped it down. Opened the butterfly as well since it is an electric motor... just be slow and easy with it. Don't use a lot of spray, less is more.

I had some MAF cleaner I picked up at Autozone. Do not touch the MAF inside, just spray it.

[Lucky1]

Thanks Xotik. My truck is running perfect but you never know when that might change.

[Xotik H3]

Took it out for weekend drive today and it's still did it 2 times. It completely went away when it got to normal operating temp.

Any other idea's?

[HUMTECH]

If it is surging on cold starts and goes away or gets better as it warms up you may have an intake gasket leak. This will usually set lean codes butnot always. Try starting it cold and spray carb cleaner at the intake ports where they mate to the cylinder heads, if the rpm fluctuates the gaskets are leaking. Easier to see if you can monitor fuel trim levels on a scan tool while doing this test.

[Xotik H3]

I drove it to work Monday and it does it evern when warm, 1500 to 1800 RPM jumps between them with no change in pedal pressure. I took the throttle body off and cleaned it VERY well Monday evening. Drove to work today... no difference. A leaking manifold would throw a lean code and there are no codes.

Could the throttle body electric motor be causing it? Looking for idea's.

[H2 Bill]

I had this same problem and it turned out to be crappy fuel...try putting some Techron additive in the tank and switch to Chevron, Mobil or shell that have the additives in them. It may take a tank or two to correct the problem. It's worth a try.

[HUMTECH]

could be torque converter clutch coming on and off. What speed are you driving? Not likely to be the throttle body, could be though.

[Xotik H3]

could be torque converter clutch coming on and off. What speed are you driving? Not likely to be the throttle body, could be though.

Well it is fixed and I had the dealer I bought it from cover it. Took it to the Hummer dealer today, they did their thing and DAMN, 1.5 Quarts low on Tranny fluid. How did I miss that? Guess I didn't check the simple things first. :raar: