LS1 running at half power - need some hints

[gjkrv8]

thanks everyone for more tips.

To me it feels like fuel or fuel delivery is an issue as a light pedal appears to be ok. Am going to have a look at the fuel filter today.

Then off to an expert this week.

Rgds

Gregg

[Modena]

Originally Posted by Philm

Try starting your car and take off once you have suffient speed turn the key off, wait 3 seconds, turn ignition back on then clutch start your car.

Take it for a drive and see how it goes.

If this solves the problem give your battery a good charge, as when starting the voltage can drop to low and the ecu will go into limp mode.

You also may not have reconnected the battery properly creating a bad connection and when under load... Starting.... You get a huge loss.

Just a thought.

Phil

This is a great idea, never thoight about doing that. Just be careful - dont turn the key all the way off or the steering lock may come on!

[gjkrv8]

Phil the more I think about it the more what you are saying sound feasible, will give it a try.

Ben - yes dont want to turn it off all the way - could be some brown stained jocks if I did that.

[sideshow]

ecus really only learn the long term oxygen mixture trims
if u were an ordinary joe blow or a granny driver u would never
realize an ecu reset when it comes to performance
if it feels like a miss then leads and plugs maybe
remove injector at a time and see which cylinder
makes I difference in revs
also remove exhaust and re drive
maybe u have blocked exhaust

but most common is plugs n leads
it's hard when the scanner doesn't say much
u actually have to use yr head
these are the jobs I always loose money on
hebehe

[Towmaster]

Have you checked your leads to make sure one is not faulty....
Sometimes the simplest things....

[jcraigau]

Mine did this when the O2 sensors went.

Ran OK under light throttle, idled like a dog and overfueled under load.
It would cough and splutter when I tried to put the boot in.
Also check the pipes around the top of the engine, the old ones used to perish at the bends at the back of the engine, escaping vacuum and all that...

More of a read here...
Australian LS1 and Holden Forums

[gjkrv8]

Prize goes to Towmaster :-)

I was listening and looking under the hood this morning and it sounded like a clicking noise from the back of the engine on one side.

put my finger down to feel the plug lead and got a nastly zap.

All other leads dont give a zap.

It is not making good contact I think as those stupid GM Spark plug heat sheilds are rubbing on the headers on this cylinder and vibrating the plug lead loose. I checked yesterday but not while the engine was running and this one is at the back and hard to get to and felt fine yesterday,

I must admit this particular cylinder the header pipe is very close to the plug shield making for a tight fit. In fact to get the plug out on this one I have to unbolt the header on this side.

I still think there are problems as I still get a jolt from where the lead goes into the plug rubber cover etc. The others dont give me a jolt.

I am going to change the led and use those flexible heat shields to see if I get better contact.

But it goes like it used to now. Should go better if I fix this lead etc.

Thanks for your suggestions - they all helped.

I still reckon I will take it to Erol for a once over tune etc as my engine is second hand (done 50,000 ks) and I dont know how "stock" the tune is etc.

Rgds

Gregg

[HSVREDSLED]

Dont be shy to sign up to Australian LS1 and Holden Forums for any tech advise on LS variants.

They love anything LS1 related and drool over LS1's in Cobras. Also you will get sorted with the best tuner in your local area...then again, I drive 90 minutes to get mine tuned so local is not always the priority?

I read you still had a MAF in your LS1? If your getting you tune 'checked' flick the maf. They are best used as sinkers for deep sea fishing on LS1's.

[boxhead]

I had an issue with my right side back lead a while ago.
But mine was a definate miss not just a lack in power.

[ICETOO]

Great news and glad it is semi sorted..and was not an expensive issue. Why is always the 5 dollar bits that cause the biggest issues...that was a rhetorical question BTW.

I suppose these cars do not come with a nice generic workshop manual that leads you through the fault finding hierarchy. This is good to know as I do like the old school hands on approach.