fiatracer

hi guys, I've just installed JDM Greddy kit on my 1600NA. It has rising rate fuel regulator, hi-flow pump, but no IC or Bipes yet. Had it on dyno, and ran into detonation, so have set timing to zero and boost to 4psi for now while I iron out a few bugs. Strange thing happended yesterday - was running well when standard crossover pipe popped off plenum, ran rough due to air leak. I reattached and all was ok, then a few miles later it started running really rich, in fact the AF ratio is over 13:1 almost all the time, and richer on boost [as expected]. Do I still have a vacuum leak somewhere..... or any other ideaS? How can AF ratio suddenly change for no *obvious* reason? cheers, Phil

PS: i am totally new to turbo stuff....

Mimime

iTrader: (1)

Try disconnecting your battery and see if it comes back to normal!

I thought all JDM kit comes with a black box instead of the rising rate.

greddymx5

iTrader: (1)

Check if the dynamo created a nice hole in the x-over pipe...Also check the harmonica...
If so, remove the airbox(@ the dynamo) on the intake and cap the hose.
(it's also a nice location to attach a bov)

Keep timing @ 6 degrees(you did adjust timing from 10 to 6?)... Maybe the boost was too high.(5-6psi of boost is a good pressure)

At 0 degrees EGT (exhaust temp) will skyrocket.... giving lots more problems in the near future.

You don't need a better fp at 6psi...Maybe there lies a problem.

Ben

iTrader: (33)

Super friggin high exhaust gas temps caused by lack of timing advance could have killed your o2 sensor. Which would force the computer into its rich limp home mode.

miataspeed1point6

iTrader: (1)

Why are the exhaust temps so high at 0 degrees?

Fergus

Yeah, set timing to 6 degrees and if the O2 sensor is blown replace it with a 4 wire one.

"set timing to zero".....no wonder it's running rich, it can't run any richer at 0degrees timing.

Ben

iTrader: (33)

because the exhaust valves open before combusion is complete, forcing the burning mixture in the exhaust

Braineack

iTrader: (62)

too advanced = high EGTs; too retarded = high EGTs, it's how you tune with an EGT gauge. sounds like a dead o2 sensors....go back to 6* base timing and repalce the o2 sensor.

Ben

iTrader: (33)

heh Luckily my parts car came with an autometer pyrometer
time permitting, I'm going to get it in tomorrow when I do the downpipe.


Since I have it on my desk in front of me still, the replacement o2 sensor is Bosch 11027, it's like $17.

greddymx5

iTrader: (1)

How did you hookup the afpr??
As i can remember, several years ago, the greddy manual had a miss in it .
It showed the return line to the tank @ the offset side of the regulator...

Did you hook it up to the vacuum at the oem fpr?

fiatracer

hi guys, thanks heaps for all the responses. I had wondered whether I may have screwed the O2 sensor. The FPR is plumbed correctly with vacuum/boost line from the plenum. I guess the sensor is burnt from the 5 or so miles when it had the bad air leak.... damn. The base timing was retarded [and boost reduced] to prevent any detonation, short term until we get FMIC and a Bipes unit for it. The kit also comes with the "make it run richer" black box, which we also have NOT fitted.

Braineack

iTrader: (62)

dont bother fitting it, it wont work well in conjustion with an FMU.

luckily o2 sensors aren't very expensive, just find a cheap universal one. you should be safe at 6°, if you hear ping, drop to 5°, but i doubt you will.

blue89turbo

Hey Fiatracer,

I like your youtube video!

Al Hounos

advanced timing will have cooler EGTs

fiatracer

there's a bunch of MX5/Miata clips on my profile.... all pre- turbo

Braineack

iTrader: (62)

correct, i was thinking about it wrong...

If you go richer than 15:1 the EGT will drop and if you go leaner than 15:1 EGT will ALSO drop, is what I was thinking...

fiatracer

decided to tackle the problem tonight. Started off with the jumper trick in the diagnostic port - no lights made themselves seen, but I wonder whether our [NZ market] cars have a Check Engine light ? Where does it usually live? Anyway, moved on to the hunt for airleaks.... remember, the crossover pipe popped off the plenum end. Voila! nice big holes in the acoustic chamber thingie, from resting on the alternator pulley - cheers to greddymx5 for getting that right. Got rid of the offending part and all's well. Runs smooth, AF ratio meter works better [has 4-5 LEDs on at any one time, rather than one or two, meaning it's easier to read] and on-boost AF ratio has settled [after a few miles of "pressing on"] at 11.8:1.... which is a pretty good safe number right? Still only at 4psi, so will look at some incremental increases and IC. thanks again all who offerred advice. Phil

Braineack

iTrader: (62)

since no IC that should be safe, if ICed I'd go leaner at that level of boost.

greddymx5

iTrader: (1)

Had that problem too... Run's like ****...

For the check engine light( the european MX5 has the same problem, no light...)
http://www.mx5club.org.nz/maintenanc...e_diagnostics/

FOUND IT IN YOUR OWN COUNTRY!!!

FHS

iTrader: (2)

What AF you tune for really does depend on how stable your conditions are. My street tuned maps shoot for around 11:5 under boost.