Na gen 2 problems eating fuel and running like a pig

Re: Na gen 2 problems eating fuel and running like a pig (Reddtarga)

Wed, 15 May 2013 08:57:22 GMT

EssDub
1100rpm hot idle... 15 degrees base timing will do that, without adjustment at the throttle body. Pull that back to 10-12 and leave it there. You're probably detonating the **** out of the engine too. Although I can't recall if the gen2 GE engine utilized a knock sensor, it's a fair bet that it'd be picking up massive knock under load and pulling the IGN timing and dumping extra fuel to compensate and try to eliminate the knock.

+1 Set it properly to 10 BTDC
And the gen2 3SGE does have a knock sensor BTW.

With reference to:
"The only thing I keep going back to is my sensor that plumbs into the intake
Is hanging in my engine bay, so maybe it's running very rich that would explain the fuel and the bad power"
No, that would NOT explain your problems.

Is the ACIS working properly?
The butterfly shaft and can seize up due to rust, and if it was frozen in the open position it would cause a loss of torque at lower revs.
While the turbo uses TVIS, the 3SGE intake intake manifold has an ACIS setup that uses spring loaded butterflies that are open when the motor is stopped but close when the motor is started.
Check to see that works ok, first with the motor stopped and then with it running.

Re: Na gen 2 problems eating fuel and running like a pig (wiz)

Tue, 14 May 2013 20:56:07 GMT

EssDub
1100rpm hot idle... 15 degrees base timing will do that, without adjustment at the throttle body. Pull that back to 10-12 and leave it there. You're probably detonating the **** out of the engine too. Although I can't recall if the gen2 GE engine utilized a knock sensor, it's a fair bet that it'd be picking up massive knock under load and pulling the IGN timing and dumping extra fuel to compensate and try to eliminate the knock.

Other thing is, take off your MAP vac line and clean it out with a compressor gun. Also check the AC Idle up lines for leakage.

As for the clutch, is there any play in the pedal at all? Just undo the hex nut on the back of the shaft and wind it back in a bit to take the bite point a little further down the pedal. Works a treat.

+1. N/A SW20's certainly do not like the timing played around with especially if it is over advanced. These are a high compression motor and the computer and timing are designed to get the max out of it in standard form.

I don't know about the other problems you are having but the advanced timing would certainly account for increased fuel consumption and poor performance.
From memory correct timing is 10 degrees TDC.

Re: Na gen 2 problems eating fuel and running like a pig (EssDub)

Mon, 13 May 2013 23:06:38 GMT

1100rpm hot idle... 15 degrees base timing will do that, without adjustment at the throttle body. Pull that back to 10-12 and leave it there. You're probably detonating the **** out of the engine too. Although I can't recall if the gen2 GE engine utilized a knock sensor, it's a fair bet that it'd be picking up massive knock under load and pulling the IGN timing and dumping extra fuel to compensate and try to eliminate the knock.

Other thing is, take off your MAP vac line and clean it out with a compressor gun. Also check the AC Idle up lines for leakage.

As for the clutch, is there any play in the pedal at all? Just undo the hex nut on the back of the shaft and wind it back in a bit to take the bite point a little further down the pedal. Works a treat.

Re: Na gen 2 problems eating fuel and running like a pig (dasic1)

Mon, 13 May 2013 22:40:39 GMT

Reading all this im thinking you didnt even look at the car before you brought it.

Re: Na gen 2 problems eating fuel and running like a pig (purple5ive)

Mon, 13 May 2013 22:10:41 GMT

pressure sensor , what exacty are you reffering to?? are you talking about a vaccum gauge ?
the O2 sensor should fluctuate between rich and optimum or whatever your says when driving at least. its quite annoying, if you want the proper reading you will need a wideband one.
cant remeber off the top of my head now if the N/A had the TVIS. if so is it working properly? if not that could be why its low on power down the bottom end.
also coolant not heating uo means cars still running rich on cold start, so until the coolant reaches optimum temp, the ecu wont let it rev hard and dump fuel to be safe.
do a diagnostic check on the car , find the diagnostic port and connect the pins (cant remeber which ones now i think its T1+E and look for error codes) then if there is any look up what they mean an go from there.

Re: Na gen 2 problems eating fuel and running like a pig (Gatesys SW20)

Mon, 13 May 2013 21:46:33 GMT

Hmm that's a good point,
I think I'm thinking to far ahead and fearing the worst
My tacho dosnt seem to be functioning correctly ATM
Works only a little
So probably a connection issue
Will have an auto elec look at it
Not the most confident at pulling a cluster out I would have no idea
What to look for, ahah so I may leave that to an auto elec
I know my combustion engines but electrics hurts my head
Ahaha

But just going off ear, it definitely does no idle at 750rpm
Idles at more like 11-1300
A semi warm.
And I would easily say 1500 cold

Re: Na gen 2 problems eating fuel and running like a pig (Mrskylighter)

Mon, 13 May 2013 21:41:37 GMT

The clutch issue I have no idea. Maybe adjustment will solve that one.

With the poor throttle response, hissing etc just wait till you have a genuine thermostat in there and the temperature where its supposed to be. You might find it will go away.
Does the car get down to its correct idle RPM? I'm not sure what that is on an NA, prob 750-800rpm

Re: Na gen 2 problems eating fuel and running like a pig (Gatesys SW20)

Mon, 13 May 2013 20:09:14 GMT

Also
My clutch literally bites as soon as I put my foot on the clutch
Now ill he adjusting that so it's kind upper middle

Could that be slightly engages whilst driving?

Also how can I diagnose a vaccum leak
I hear alot of hissing
But I mean any symptoms from throttle and revving etc
Like, it has poor throttle response and when it does pick up revs it lingers for a while longer then usual sounds a little like its hunting before dying down

I know these are novice questions
I've done a lot of work on previous mr2s myself and do have a sound knowledge on cars and how they work
Just want someone else's insight :)

Re: Na gen 2 problems eating fuel and running like a pig (Gatesys SW20)

Mon, 13 May 2013 18:43:47 GMT

Yeah I don't mean to disregard what you have suggested
Sorry if I came off as rude

Thanks for your help :)
Ill let you know how it all goes

Re: Na gen 2 problems eating fuel and running like a pig (Mrskylighter)

Mon, 13 May 2013 18:42:02 GMT

Alright then, good luck :)

Re: Na gen 2 problems eating fuel and running like a pig (Gatesys SW20)

Mon, 13 May 2013 18:32:12 GMT

There is a pressure gauge installed
It gets power and lights up with the dimmers

Just has the wires ziptied together in my engine bay
I need to install a sensor and connect it up ahaha

I really wouldn't think it would be so slow down low
With it only being semi warm I thought it may contribute

But maybe a combination of both the sensor as its not changing the mappin as the throttle opens and creates a higher velocity of flow through the intake

The cooling system

And perhaps a timing problem

All easily fixable will be sorting all this week :)
So that's fine

Re: Na gen 2 problems eating fuel and running like a pig (Mrskylighter)

Mon, 13 May 2013 18:17:15 GMT

Also what do you mean by this comment?
That may be inaccurate as my pressure sensor is connected to everything but a pressure sensor lol

And with the timing just set it at what the workshop manual recommends. Just get it running right than start fiddling with it later.

Re: Na gen 2 problems eating fuel and running like a pig (Mrskylighter)

Mon, 13 May 2013 18:09:41 GMT

Did you say the car never gets up to correct operating temperature? Only up to a 1/4?
If that's the case then what your seeing is normal. The ecu still thinks the engine is cold and is therefore running rich as part of the sequence to get it up to temperature.
The previous owner might have put a TRD thermostat in or no thermo at all due to a problem with the cooling system.

The temp probe hanging in the bay doesn't matter its still reading the ambient temp of what the filter would be sucking in (maybe a degree or 2 off)

Na gen 2 problems eating fuel and running like a pig (Gatesys SW20)

Mon, 13 May 2013 18:00:42 GMT

Hi guys
My Na newly acquired has an issue
On Wednesday I'm having the coolant flushed, filled with toyota red and bled
A new thermostat installed and gasket

The timing advanced to 14-15deg

The clutch bled

Throttle adjusted
Going to stay back at work with one of the mechanics and smash all that

But one issue I keep scratching my head at is this:

It eats fuel, but is very very slow has stuff all power down low
And kind of picks up, up top,
Now I was thinking maybe the timing is off?
The only thing I keep going back to is my sensor that plumbs into the intake
Is hanging in my engine bay, so maybe it's running very rich that would explain the fuel and the bad power
Also there is a AFR gauge installed and it reads rich all the time dosnt move but
That may be inaccurate as my pressure sensor is connected to everything but a pressure sensor lol

Anyone have any ideas?