Is My Car Running Too Lean?

Discussions relating to Turbochargers, Superchargers, Induction, Engine Mods, Exhaust Mods, and other items specifically to make your MX5 or Roadster put out more power.

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SkilletKid
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Is My Car Running Too Lean?

Post by SkilletKid » Thu Feb 27, 2014 12:03 pm

Pulled out my spark plugs to check them after my mechanic friend mentioned the car felt like it was running lean.

I put these in new around 1648 kms ago around the same time I did a Timing Belt job. I have a suspicion that my timing belt might be a bit off. Opinions?
Attachments
2014-02-27 10.35.10.jpg
From Left to Right: 1 2 3 4
2014-02-27 10.35.22.jpg
1 2 3 4
2014-02-27 10.36.02.jpg
1 2 3 4
2014-02-27 10.37.17.jpg
"Yes, you got that, 16 years of [MX5] ownership and you too can become the Obi-wan Kenobi of not giving a s**t." - Moti

SLYDIT
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Post by SLYDIT » Thu Feb 27, 2014 6:34 pm

"felt like it was running lean"?
is it missing?
if it is missing it ore likely to be leads/coils or plugs. the fuel system is pretty robust.
RED '90 TURBO.
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WideOpenThrottle
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Post by WideOpenThrottle » Thu Feb 27, 2014 9:02 pm

1989 NA 1650
1998 NB 1800
2005 NC 2000
1990 Landcruiser
Surfboard
Push-bike
Hiking shoes

Snapfrozen
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Post by Snapfrozen » Fri Feb 28, 2014 5:20 pm

Is that oil on the thread?

SkilletKid
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Post by SkilletKid » Fri Feb 28, 2014 7:15 pm

Cheers for the replies guys;
@SLYDIT
It's got a slight hesitation and a fair amount of vibration on quick, small blips of the throttle from idle if that's what you mean but no misfire that I can hear.

@WOT
Cheers for the link! After reading through it, it seems I've got too much timing (#4 is the best indicator with the others not even having a colour change on the ground strap). And what might be evidence of detonation on #1.

@Snapfrozen
No it's not oil; just some antiseize that I put on there (might have put a bit too much looking at it now).



I'll be redoing the belt tomorrow and probably put some fresh plugs in to do another check after it's done.
"Yes, you got that, 16 years of [MX5] ownership and you too can become the Obi-wan Kenobi of not giving a s**t." - Moti

SLYDIT
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Post by SLYDIT » Sat Mar 15, 2014 10:47 am

any news on this? what was the outcome??
RED '90 TURBO.
SCARING PRIUS DRIVERS SINCE 2002

SkilletKid
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Post by SkilletKid » Sat Mar 15, 2014 12:33 pm

Double checked the timing belt, took it off the cam gears and realigned everything. Put in new plugs as well. Set the ignition timing to 10 for now (was on 11/12) to try and reduce how many changes I'm doing that could possibly be causing the issues.

Waiting for a bit more mileage on the new plugs before I pull them and check them again. Will update this once I have pics etc.
"Yes, you got that, 16 years of [MX5] ownership and you too can become the Obi-wan Kenobi of not giving a s**t." - Moti

SLYDIT
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Post by SLYDIT » Thu Apr 17, 2014 5:18 pm

still waiting....
RED '90 TURBO.
SCARING PRIUS DRIVERS SINCE 2002

SkilletKid
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Post by SkilletKid » Fri Apr 18, 2014 12:46 pm

This is after 1307km of driving;
From Left to Right is 4-3-2-1
Attachments
2014-04-18 12.19.03.jpg
2014-04-18 12.19.08.jpg
2014-04-18 12.19.25.jpg
2014-04-18 12.19.35.jpg
2014-04-18 12.19.40.jpg
"Yes, you got that, 16 years of [MX5] ownership and you too can become the Obi-wan Kenobi of not giving a s**t." - Moti

WideOpenThrottle
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Post by WideOpenThrottle » Fri Apr 18, 2014 1:34 pm

Would be interested to know what plug type and gap,fuel type and timing you are running?
1989 NA 1650
1998 NB 1800
2005 NC 2000
1990 Landcruiser
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Teamjelly
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Post by Teamjelly » Fri Apr 18, 2014 4:52 pm

I wouldn't worry about those plugs too much
There's no sign of detonation
The BKR7E plugs used to look exactly like that in my Turbo NB, to the point I was running the full load mixture at 11.0:1 and the high boost timing at only 11' BTDC to see if that would help
It didn't.....
I solved it by fitting a set of NGK V-Power 9 Racing plugs, Part number R5671A-9
And straightaway with no alterations to the tuning, the plugs are always a beautiful light Tan colour. I can run the timing quite a bit more advanced than before with zero detonation, which has increased the power quite a bit too.
I think the plugs were just running a bit hot and burning off any deposits. :)
Sticking feathers up your butt does not make you a chicken

SkilletKid
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Post by SkilletKid » Sat Apr 19, 2014 2:37 pm

Been running 95/98 (not E10).

NGK BKR6E11; gap was 1.1.

I set the timing to 10deg after I switched to these fresh ones since the last time I took a picture. Just find it a bit weird that the porcelain is that clean near the tip. And mind you Jelly, this is without a turbo haha.

Edit: And it seems odd that the ground strap is that clean considering the stock ECU is known for running quite rich.
"Yes, you got that, 16 years of [MX5] ownership and you too can become the Obi-wan Kenobi of not giving a s**t." - Moti

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