hesitation, comes and goes

[Aaron10 10]

hey guys, need your sound advice.

 

long story short, 92 g60, new standard charger, schrick cam, wossner pistons, decat, downpipe, bored out to 1.9, green injectors, new paper air filter, 68mm pulley.

 

basically had it now a couple of months and thats how i bought it. going pretty well and smooth up the rev range. i have since changed the exhaust and also did a boost return delete. Driving really well no issues and i have had those mods a couples of weeks now but today it had a real bad hesitation on full throttle through all gears, then it would go away on the next full throttle run but return the next etc etc.

 

Any suggestion as to what the issue could be?

 

Many thanks in advance, Aaron

[TanpreetBhachu 10]

Are you losing pressure on the accelerator pedal?

 

Sent from my ONEPLUS A3003 using Tapatalk

[volksworld13 0]

Clean all earths on side of head and battery tray.

Check oxygen sensor operation and clean ground .

Check vacuum lines for splits to ecu . Should be 1 meter long exactly.

Check fuel pressure regulator vacuum hose.

 

Check wot switch on throttle with a multimeter.

 

These g60 are strange when they get to this age,I'm also having starting problems that I need to resolve.

[Aaron10 10]

Are you losing pressure on the accelerator pedal?

 

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Not really sure what you mean but accelerator works as it should I guess, didn't feel any difference to normal bar the obvious slowness then would go then slow again but no consistency with the splutering if that makes sense

[Aaron10 10]

Clean all earths on side of head and battery tray.

Check oxygen sensor operation and clean ground .

Check vacuum lines for splits to ecu . Should be 1 meter long exactly.

Check fuel pressure regulator vacuum hose.

 

Check wot switch on throttle with a multimeter.

 

These g60 are strange when they get to this age,I'm also having starting problems that I need to resolve.

 

Ok I will get straight on to those things tomorrow. Thanks for that. Yes funny old thing but we love them.

[VEEDUBBED 0]

Sounds suspiciously like Digi lag, what chip is in the ecu?

[Aaron10 10]

Sounds suspiciously like Digi lag, what chip is in the ecu?

 

The chip and pulley kit came Jabba sport. That's what the receipt says anyway and there a list of mods underneath it, standard head, wossner pistons, 4 branch and green injectors, and schrick cam.

 

But I know there's been head work (full rebuild and bored out) and exhaust has been fitted after that.

 

What is digi-lag?

 

Thanks

[Dox 23]

When its dark outside run the engine with the bonnet open and mist water around the plug leads / dizzy cap with a hand spray bottle and watch for sparks migrating between leads.

[VEEDUBBED 0]

Digi lag is a momentary hesitation when the engine goes full lean, SNS chips eliminate this by writing it out of the chip's code. Some days the car goes really well, others it hits a wall.

I had it on my first turbo'd 8v g60 engine, bought a used Pitstop developments st.5 chip and the car was transformed. Digilag could easily wipe out your pistons/ringlands in a couple of seconds, it leans out under full power and detonates.

I would have thought a place like Jabbasport would have changed the chip but you never know..

Open the ecu and check the eeprom inside mate.

Indeed do as Dox suggested but if it were the leads I reckon it'd be more of misfire than fuel lean off hesitation.

There are many other things to check too, for, fuel pressure under load, fuel injector wiring harness falling to bits and shorting, partially blocked fuel injectors..

If you can, this would be ideal, connect up a wideband afr gauge and see what kind of fueling mixture you have under full load, that way you'll if it's fuel related or something else.

[Aaron10 10]

Digi lag is a momentary hesitation when the engine goes full lean, SNS chips eliminate this by writing it out of the chip's code. Some days the car goes really well, others it hits a wall.

I had it on my first turbo'd 8v g60 engine, bought a used Pitstop developments st.5 chip and the car was transformed. Digilag could easily wipe out your pistons/ringlands in a couple of seconds, it leans out under full power and detonates.

I would have thought a place like Jabbasport would have changed the chip but you never know..

Open the ecu and check the eeprom inside mate.

Indeed do as Dox suggested but if it were the leads I reckon it'd be more of misfire than fuel lean off hesitation.

There are many other things to check too, for, fuel pressure under load, fuel injector wiring harness falling to bits and shorting, partially blocked fuel injectors..

If you can, this would be ideal, connect up a wideband afr gauge and see what kind of fueling mixture you have under full load, that way you'll if it's fuel related or something else.

 

Ok will check and take pics of epprom tonight and check some of the things that have been mentioned. I find it strange that the car was going real well, pulled like a train and only last 2 days its developed this hesitation on full load. Didn't like full throttle at all. I checked the WOT switch and full contact is being made on when I manually move the accelerator cable. Will post later, thanks for all replies so far.