Over revving on start up and stalling for no reason on a 6MGE

**Johnzoku** · 12-02-2007, 07:21 PM

Over revving on start up and stalling for no reason.

After I did my manual conversion ive noticed two things that have come to my attention

No. 1 – on start up especially when it’s cold my engine will rev around 1200 to 2000 RPM apposed to the normal 650 – 800 RPM. But later on when its warmed (half way up the meter) it idles normal. Is there anyway of fixing it.

No. 2 – when I first started driving the Soarer after my manual conversion it would stall when you slow down around 20 – 30 kms before a stop. At first I thought it was just me since I didn’t bleed the clutch right and wasn’t used to the clutch just yet. But ive bleed the clutch since then and it still happens and today on the way home from work it done it about 5 or 6 times. I tried rolling to a stop in neutral, slowing down using gears to keep the revs up till I stop and ive come to the conclusion that it isn’t me.

so could this problem have something to do with an incorrectly installed clutch or might it be in the fuel delivery department? Fuel pump, fuel lines, etc… I haven’t changed the fuel filter and I think its over due but apart from that I cant figure it out.

Any help would be much appreciated 

**Screamn_Sleeka** · 12-02-2007, 07:31 PM

Are you using a Manual ECU?

**Johnzoku** · 12-02-2007, 07:32 PM

auto ecu

**thechuckster** · 12-02-2007, 07:56 PM

1- aux-air valve needs looking at

2- TPS needs adjusting - the idle switch in it is not triggering (ECU uses the IDL switch to know when your foot is off the throttle so it wont decell fuel-cut at low rpms) OR the dashpot valve thing on the throttle is not quite right (it slows down therottle closing over the last 2-3mm of travel so the throttle cast slam shut and starve the engien of aior - particularly when the aux air valve has shut of escess air to control idle speed.

a read of the TSRM for MarkIi supra will help
http://www.cygnusx1.net/supra/librar...KII/index.html

you should bookmark this site now.

**CrUZida** · 12-02-2007, 11:20 PM

Originally Posted by thechuckster

1- aux-air valve needs looking at.

That would be the ISCV.
It needs cleaning.
And you need to make sure the throttle plate closes 100%, not 95%.

And set the TPS to IDL like chuck said.

After that, it should all be good.

1200-1500 on dead cold startup is normal, probably for 20 secs or so.

2000rpm on startup is not.

**Johnzoku** · 13-02-2007, 09:12 AM

thanks guys, ill have to check them out on the weekend

i do have the TRSM booked marked tho i jsut find it difficult diagnosing the problem but i guess thats what the troubleshooter is for.

also i know ive got a crack in my piping between the AMF and throttle body as well so im guessing thats contributing for my bad tune.

**thechuckster** · 13-02-2007, 10:15 AM

Originally Posted by xcedricx

ive got a crack in my piping between the AMF and throttle body as well so im guessing thats contributing for my bad tune.

fix that first - it will compound the problem and make you run lean.

**CrUZida** · 13-02-2007, 10:29 AM

It cost me about $50 to replace every bit of rubber on top of the motor.
Also clean out the TB, the ISCV, and the oil pressure regulator.

After you do that (and adjusted the TPS), the motor will run like its brand new.

**Johnzoku** · 13-02-2007, 10:37 AM

was that all new parts, or from your local pic and pull? i was thinking of getting one of thoes rabid chimp intake piping kits but 50 bucks is the better option

ive read the ISCV thread and it makes a lot of sence, my engine is more grese than engine. ill get stright onto that on the weekend... is INOX ok on the oil pressure regulatior and TB as well?

would this imporove my fuel econo,? cuz at the moment im around 8km/L and when i had the auto i was on more like 10km/L.

big thanks, ill let you guys know how i go.

**CrUZida** · 13-02-2007, 10:42 AM

I used carby cleaner to clean everything.
I don't know how well INOX would work.

That was all new parts, obivously nothing genuine. Just a matter of taking the existing hoses into the shop and matching them up with something cheap and generic.

I found my manual used a lot less fuel than the auto, except on the long country runs (revs higher in top gear)

**Johnzoku** · 13-02-2007, 11:36 AM

50 bucks worth of genuine wouldnt even get you one hose, haha... but thats a good idea, ill check that out... where did you go to get the parts? supre cheep etc... or a hose place.

and im pretty sure i should be getting better fuel eco. with my manual but i guess its jsut the engine tune ATM.

**CrUZida** · 13-02-2007, 12:18 PM

My local auto parts store (proper auto parts store, not a chain).

**Johnzoku** · 18-02-2007, 08:43 PM

cleaned my ISCV with carby cleaner yesterday and today I replaced the coupling between the accordion piping and the throttle body with one of those "Monza" silicon intercooler bits from supercheep, good fit and seams to go all right although im not sure how well it will hold up over the top of the motor with the heat but it works none the less.

this is how the old coupling looked, I dear say this would of played a part in the bad tune... the other couplings are in better shape but im going to replace the parts with some copper piping and those silicon intercooler piping bits.

The start up rev is around 1200 now and the stalling has happened only once since I did the work. So once I fix the rest of the inlet piping and adjust the TPS it should go a lot better.

Thanks guys.