Flatspot Between 200RPM-3000RPM & A Power-Surge.??

[Lethal_1]

Hi there ... I have a " V6-VX Commodore Lumina " ...
I don't know how to explain it ... But it's definitely Not normal.?

2 Separate Problems ... 1. Acceleration Flatspot ... 2. A Power-Band-Surge

1st one ... The Acceleration Flatspot.??
Initially even when taking off from a stand still, just normal acceleration, it *feels like* it's gurgling & bubbling like it's running on 5-Cyl as U take off.!?
Anyway ... We're cruising along @ 100Klms, Taco is showing aprox. 1800-RPM ... As U try & accelerate to overtake, I get that bubbling again, but also No increase in speed.??
I have to press the pedal aprox. 1-2" ... Yes, Inches, B4 it kicks down from 4th, down to 3rd & 2nd.!! - * How do we fix this.? - What is it.?? - How do I fix this Flatspot.?

2nd one ... The Power-Band-Surge.??
When U floor it ... I get that flatspot @ 1st ... but once past that 3500-RPM mark, when U hit 5000-RPM ... I get a Power-Surge, like a Turbo-Hit, till U make 5500-RPM.??
* With all this going on, it's also PINGING.!! - I use PULP ... All The Time, Since 0-Klms.!! - How do I fix this "Power-Surge".?? - It's Not normal.!! - I don't know why it's doing it.??

[LowVp]

how long since it has had plugs and leads and even coils and if not that then i'd have a look at the cats, could be possible that a piece has broken inside and is choking it but the power surge rules that out

[pablo]

I recon the H.T. (plug) leads are knackered!

[Lethal_1]

Hmmm.? - Spark Plugs ... It's been 7,000-Klms since it's 130,000 K service.!
Leads are originals ... The Cat is also original ... Coil ... Original . . .

All this has only just happened since I had the " Engine Mounts " replaced.!!
Tried Dis-Connecting the Battery to see if it'll reset the computer ... Nope.??
It's annoying the crap outta me.!! - My Mechanic has checked these problems twice now ... nothing.? - Not even a " Fault Code ".??

I recon the H.T. (plug) leads are knackered!

Yeah.?? - I'd give that a try.!! - What Leads do U rekon to upgrade with.?? - Btw ; What does H.T. mean.?

[ACEMonkey]

What do you mean by "gurgling & bubbling"?? Is it a sound of something that is rotating loosely and giving a kind of a weird rattling noise?

Have you tried flooring your accelerator while the car is in Neutral or Park? Does it make the same noise or flat spot?

[Lethal_1]

Gurgling & Bubbling as in ... Thats the noise it makes from the Engine / Exhaust as U rev thru the gears (automatic)

- The noise / flatspot happens @ 2,000-RPM even in Park.!! - But I'll double check that tomorrow & report back.!!

[LowVp]

well if the ignition parts are all original then thats where i would be point the finger. new plugs and leads for starters and go from there

[Lethal_1]

well if the ignition parts are all original then thats where i would be point the finger. new plugs and leads for starters and go from there

Yeahh ... I'll definately change the Spark-Plugs & Leads ... But if there's nothing wrong with the Coil, no need to replace.!
Obviously I will have them all checked anyway ... Problem only started (coincidently) since the Engine Mounts were replaced.? (been checked twice since)
He's gonna run a Scan Tool on the Computer or something next WED. Then while driving the Car, see what the Scan Tool says.?
- Always seems to be around the 2,000 RPM mark.? - No matter what speed I am doing.! - Gotta be something fishy there.?

What do you mean by "gurgling & bubbling"?? Is it a sound of something that is rotating loosely and giving a kind of a weird rattling noise?

Have you tried flooring your accelerator while the car is in Neutral or Park? Does it make the same noise or flat spot?

OK ... I have now done a check on this ... While in Park or Neutral ... Nothing.? - No Gurgling or Flatspot.?
Tho it does have a form of tightness, still around the 2,000 RPM mark.? - No rattles etc. Just normal apart from that.?
Flooring it in Park & Neutral has a normal rev range with no restrictions.!! - No Surging etc. Only when in gear.? - Hmmm.?

[ACEMonkey]

If you are sure all your pulleys and bearings are ok, I suggest giving your computer a reset and hopefully that clears that tightness around the 2000rpm mark.

The gurgling, flatspot and surging occuring while your car is in drive indicates perhaps a damage somewhere in the transmission, possibly from when the engine mounts were being done. This could be either your clutch plate slipping or even your lsd playing up.

[tyrefryer]

maybe ur car just has too much power and its spinning ur wheels and making TC come on haha....actually it may have something to do with TC if its fitted cos that makes the car ghurgle, maybe fuel filter is on its way out?

[a9x2doorhatch]

get 3 cans of carbie cleaner and go nuts take off everything got to do with air induction. take the lid off the box above the manifold and give it a clean clean it all till its brand new. put everything back adjust the idle its it should run like new. it happend to my v6supercharged at around 115k done that and did a service. brand new

its a common carbie problem

[ACEMonkey]

umm...carbie in a fuel injected car? what are you on about?

[a9x2doorhatch]

let me guess u never worked on a car before acemonkey ?

[pablo]

Just thinkin', what about the 'knock sensors' they are immediatelly above the engine mounts, wonder if they are not connected or the wire has been damaged during the mount replacement?

Pablo

[Lethal_1]

...::: Update, Oct, 4, 2008 :::...

Righty-O ... Had my car tested aprox. 2 weeks ago ... Sorry for the delay ...

My Mechanic kept the car overnight & did a " Pressure Test " ... And Yes.! - Found a Leak.!! - Fixed, Done.!
But another test also told him, that the " Head Gasket " is on it's way out.? - Let me explain, coz it's probably right.!

In the last 6-months ... I have checked my Radiator for water ... BUT ... On 3 occasions, I have forgotten to REPLACE the Cap.??
I never normally, check the water, coz it's always right, but there must of been a reason for me to check it.?? - Anyway ...
The Tank Run Dry ... Steam P***ing out the front, along with the Smell & HOLY S*** ... I drove just over 45Klms with NO CAP.??
The 1st one, though it's not right, was OK enough, that I got away with it.?? - 2nd was pushing it, the 3rd was the last straw ... MY Fault.!!

So there U go ... That sort of explains the " Surging " ... Coz of the water in the Head.??
The " Flatspot " was still there initially ... So thats 2 weeks now ... But for some reason, it has " Settled ", in the last 3 days.?? - Weird But Good.!!
I did notice the " Power Button ", was not ON as usual, & the car was running fine, just yesterday, I turned the " Power " back On ... Still going good.!!

There U Go ... Just thought I'd update this, tho embarrassing ... I had to tell ... Thanks for the Help Guys / Girls ... Anything *New*, I will post back ... Cheer's.!!