Hi,

I have dont a couple of minor mods recently and now my engine
splutters at higher boost pressures of 15psi.

I wired in the 4.7v zener diode mod ... part no (Zener 1W 4V7
1N4732/BZX85C4V7) it is 1 or 1.3 watt part. Is this the right
component?

I wired the zener from signal BLUE/BLACK (L-B 3) to ground BROWN (BR
1) with the band facing the signal wire.

I next turned up the boost on my turbosmart pneamatic boost
controller to 15psi.

Now when you drive the car it splutters and coughs once it gets to
15psi ... up until usually 14 psi it is ok. Its not like what fuel
cut used to be like but it aint good.

I just wanted to make sure that the fuel cut mod I did was done
correctly.

So what does everyone think .. mabey the air fuel ratios are messed
up now at higher boost (leaning out) and I should wait until I get
aftermarket engine management before I run higher boost or that fuel
ratios should still be reasonable seeing its only a few extra psi and
my fuel cut mod is not working properly.

Any advise appreciated.

Supras particularly JZA70 are a bloody good performance buy!

Check your plugs And wires... I had that Happen and thought it was fuel delevery, but after looking further into it, it was a bad plug wire.

http://64.4.18.250/cgi-bin/saferd?_lang=EN&hm___tg=http%3a%2f%2f64%2e4%2e18%2e250%2fcgi%2dbin%2fgetmsg&hm___qs=curmbox%3dF000000001%26a%3dc833421f5a520550fec36aa8d87ef404%26msg%3dMSG1046142196%2e72%26start%3d556804%26len%3d73069%26mimepart%3d3%26disk%3d64%2e4%2e18%2e67_d111%26login%3dj_300z_92%26domain%3dhotmail%2ecom&hm___login=j_300z_92&hm___domain=hotmail.com&hm___ts=1046142355&hm___ha=fffc94429621a2fbd617092030b0773a&domain=hotmail.com

Try gapping your plugs to 27 and see if it still does it.

Id aggree, its plugs.

adi
1992 original JDM JZA70 2.5tt 'Limited' - Decat, hybrid turbos.




http://www.jzasupra.com

Yeah, I fixed the problem ... I just pulled all the plugs out,
cleaned the head where the plug sits of oil, dirt etc, cleaned the
silicon boots for the plugs, and the stems of the coils then reduced
to gap on the plugs to just over 0.8mm and problem gone.

The plugs Im running are pretty new. The are NGK R Laser Platinum BCPR6EP-11 3350 units about $20.00 AUD each.

Now it runs hard and smooth all the way to red line with 15psi .
Plugs showed no sign of overly lean mixtures and fuel cut mod appears
to be working fine. Its all good.

By the way the car is a 90 model JZA70 Supra and the engine the 1JZ-GTE with the stock twins.

Supras particularly JZA70 are a bloody good performance buy!

quote:

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Originally posted by BLKMGK:

quote:

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Originally posted by jts94N/A-T:
Check your plugs And wires... I had that Happen and thought it was fuel delevery, but after looking further into it, it was a bad plug wire.

http://64.4.18.250/cgi-bin/saferd?_lang=EN&hm___tg=http%3a%2f%2f64%2e4%2e18%2e250%2fcgi%2dbin%2fgetmsg&hm___qs=curmbox%3dF000000001%26a%3dc833421f5a520550fec36aa8d87ef404%26msg%3dMSG1046142196%2e72%26start%3d556804%26len%3d73069%26mimepart%3d3%26disk%3d64%2e4%2e18%2e67_d111%26login%3dj_300z_92%26domain%3dhotmail%2ecom&hm___login=j_300z_92&hm___domain=hotmail.com&hm___ts=1046142355&hm___ha=fffc94429621a2fbd617092030b0773a&domain=hotmail.com

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Dude, why the heck do you have a link to your HotMail INBOX as your sig?!

1995 Supra TT, T-78, FMIC, AEM ECU tuned by ME

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Sorry it was a pic of my car..... I couldnt get the pic to post...