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Hi my mate has recently purchased a schmick Stagea from JaysR33 off this forum...

Has just had a service done and we had to replace the exhaust manifold as it was cracked and warped, its had new plugs etc put through it...

but not long after he got it down here (but before it had a service), its developed a misfire... i haven't had a chance to get a good look at it, but i went for a quick spin last night and its misfiring at about 2500rpm and then struggles right through past 4000rpm... was going to try a different set of coils out of my car, only to find this has the latter type with ignition modules built into coils

He said it has a UniChip in it... but i am guesing this is a plug in type thing,

How can i check for fault codes if there is any?

Only thing he said he has done since it started to misfire was install an amp and sub which were supplied with the car, i though maybe when they ran the RCAs they might have bumped something or its getting interference?

It would be appreciated if JaysR33 (if thats who he bought the car off) could enlighten me more about the UniChip...

cheers

Tim

G'day Tim,

Hmm, miss fire..

When you say it had new plugs put through it do you mean they left the near new Iridums in it that I put in, or did they put new plugs in when he had the service done ?

What your discribing sounds like the typical plug gap too big problem.

If they put new plugs in at the service I dare say that's the problem. I bet they just slapped the plugs in and didn't gap them down to 0.8mm.

Also, if they put new plugs in it I'd be asking for the Irdiums back cause they were about $140 and only 6 months old...

The missfire won't be anything to do with the Unichip. The Unichip hasn't missed a beat since it was installed.

A few months ago I had a loose earth wire on the coilpacks which caused a coilpack not to fire, but it wasn't firing right through the rev range, then within 10mins all coilpacks wouldn't fire. Ended up being an earth wire was a little loose !! They tightened the bolt on the earth wire about half a turn and it was perfect again !! Amazing how a little wire can stop the car !! The earth wire that was loose is (when your at the front of the car looking at the motor) at the back lefthand side of the motor. I think it was two or three wires together on one brass lug bolted down to the head/mount.

Also, what fuel type have you got down there ? The Unichip was tuned on 98RON BP Ultimate, so I'd stick to 98RON fuel if you can. If not, disconnect the factory boost soleniod which will bring the boost down to about 5-6psi until you can get the Unichip re-tuned to the lower RON fuel.

I wasn't aware of the cracked exhaust manifold :( The tuner that I used to service her never picked it up either :rofl: Must have been in a hard to see spot or something, but let Phil know that I wasn't aware that it had a crack...

I hope that helps, I'm happy to help out anyway that I can.

Cheers

J

Ahh, just re-read your post. Missfire was before the service. Yep, check the earth wire that I discribed above and make sure your using 98 RON fuel. Even though it uses the Unichip it still uses the factory knock sensors, so if your using 90/95 RON fuel it'll knock/ping and go massive retard on the timing..

Disconnect the factory boost soleniod and it'll revert back down to the 5-6psi and I dare say that the flat spot won't be as bad.

A retune of the Unichip (for lower RON fuel) should only be $200 or so, they'll just need to pull some timing across the whole range etc..

J

Cool, yeh i didn't really get to have a good look at it in the dark last night, but ill check all those things on saturday... yeh he got the plugs back, was just something the mech tried...

yeh the exhaust manifold was cracked on the inside so something you can't pick, luckily i had a spare at home...

id say 95RON fuel 'may' have something to do with it but more likely loose earthing and so forth

Must say its a really nice neat car otherwise, hadn't really looked at one before!

Thanks for your help

Tim,

No worries Tim.

I remember the tuner telling me that he gave it a heap of timing when he tuned the Unichip (fairly aggressive tune), so I'd say that's is fairly advanced and may cause problems with the 95 fuel.

The safety retard on the Stagea ECU's is very very savage, massive loss of power. If you disconnet the boost soleniod and run stock boost and the flat spot goes away or reduces right down then I'd say it's cause of the fuel.

But also make sure the plugs are gapped down to 0.8mm.

Sooooo the first things I'd do is;

1. rip the plugs out and make sure they are at 0.8mm.

2. if that doesn't stop the flat stop, unplug the boost soleniod and see if helps.

3. get the Unichip retuned.

If the Unichip get's retuned, think about getting it tuned on 90 RON fuel, he'll be down a bit in power but at least he'll be able to use just about any fuel so he'll save money in the end.

J

No worries Tim.

I remember the tuner telling me that he gave it a heap of timing when he tuned the Unichip (fairly aggressive tune), so I'd say that's is fairly advanced and may cause problems with the 95 fuel.

The safety retard on the Stagea ECU's is very very savage, massive loss of power. If you disconnet the boost soleniod and run stock boost and the flat spot goes away or reduces right down then I'd say it's cause of the fuel.

But also make sure the plugs are gapped down to 0.8mm.

Sooooo the first things I'd do is;

1. rip the plugs out and make sure they are at 0.8mm.

2. if that doesn't stop the flat stop, unplug the boost soleniod and see if helps.

3. get the Unichip retuned.

If the Unichip get's retuned, think about getting it tuned on 90 RON fuel, he'll be down a bit in power but at least he'll be able to use just about any fuel so he'll save money in the end

i may have a a stock manifold for sale!! what are they worth?

Ok i forgot to update this, but anyway

Took it all apart, which turned out to be a royal pain in the arse, few bolts were stripped so spent ages taking them out... anyway

Gapped the plugs

Checked and cleaned all coil packs

checked earths

took for a run, and there was no change.

unplugged solinoid, hardly any different.

put it all back, scratched our heads... ended up cutting the wires to the UniChip and wiring it all back to factory, but still be able to plug the UniChip back in.

Took for a spin and no more mis mis, well till real high in the rev range, which we later discovered was due to it only having 91RON fuel in it!!!!!!!!!

So plans are to get it down to hobart and put the UniChip back in and have it tuned to 95RON, with more sedate timing :P

G'day Tim,

Sorry for the late reply, been up in Forster for a week holiday. Got back yesterday and the forums have been upgraded and I can't post under my old user name :( PM box is also totally full so can't receive PM's !!

Yep, I'm 100% sure that it's cause of the fuel. Going from 98RON down to 91RON on a car that has lots of timing pumped into it will definatly cause problems.

Like you said, leave the Unichip out until you get a re-tune. Re-tune should only cost you $200 or so, just remember to get them to pull the front drive shaft out if they only have a 2 wheel dyno.

J

Car running a bit better now, still missing high in the rev range. Been running either 95RON or 96RON with the unichip off, even starting to backfire higher up in the revs, cheers for the help so far. Tassie is so shit, no good fuel!

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