Fj20 Multiple Dyno Problems, Wastegate Issues To Down On Power

[Gareth87]

Hey Troy,

Thanks for your input, i have been extremely pleased with turbosmart and how they have handled the issue with my gate. I have yet to road test it, but when i put the gate back on yesterday and pressure tested the system again, there was not even the hint of a leak from where it was leaking previously, so for that i am very grateful. However, i will give you feedback as soon as i drive it again.

I will pm you a link, which i am keen for you to read, not for my benefit, just an interesting read.

Now as for the AFR's. That is a valid point you have raised about the plug fouling. however, i will call the dyno back and get them to checkup what AFR it was running, but from memory it actually leaned off after 7k rpm. nothing richer than 11-11.5. The one thing that i do recall, which i no doubt feel is a problem, was just as it was being backed onto the dyno, the engine was stalled and took a lot of cranking to start again. When it did, it smelled very fuelled up. So i can only guess it fouled a plug before the first run. The plugs came out when i comp tested it and we cleaned them there and then. It proceeded to make normal power again.

The plugs im using are NGK racing competition B8EGV. They are a fine tipped plug.

In addition Troy, those runs are layed over each other, but are from 2 weeks apart. Before i noticed the issue and then after.

My concern in all of this is im worried about what consequences this may have on the 4th pot. I know the plenum design isn't great but like i said before, it have had plugs running the same before.

G

[Gareth87]

I just re checked the leads for resistance and moved them around and found the following.

#1 - 12-13

#2 - 15-16

#3 - 18-19 (up to 20 depending on how i hold the lead)

#4 - 13-14 (up to 16, 17)

G

[ISL33P]

Gareth - congrats on building something like that - the plenum i mean - at the age of 16...there are plenty out there (and on here that have never done anything apart from bolt on an air filter or intercooler and think they know it all.

The plenum would cause the rich mixtures in cylinder 4 as you are experiencing. The turbelence created at the rear of the plenum is the reason for this - turbulence or air pockets reduce flow and result in the rich mixtures. This is typical of that style of plenum. Strangely all the top 2jz race teams, here and in the US run this style but also have the luxury of adjusting fuel mixtures per cylinder to overcome this....personally not the ideal way, but whatever works for some people is enough.

Simply run mixtures that air safe for cylinders 1-3 and that will bandaid fix that issue.

[T04GTR]

dont run b8egv's its not a rotor. you need to use plain old bpr7e's, you will find it will feel much stronger the whole way thru.

and with your plenum. much of muchness. getting a stock one will yield gains. both off and on boost.

it may pay to have your "end of injection" timing looked at, i mean they should fire at a closed inlet valve to get the best mixture and stable combustion.

also, this may sound funny but all the injectors are wired in corectly? in firing order? not 1234 but 1342 at the ecu. aka inj output at ecu,1 to 1, 2 to 3, 3 to 4 and 4 to 2?

[ISL33P]

only thing is that the stock plenum suffers from the same, or well at least to a simlar extent, as does the one there now. cylinders 1-3 flow quite evenly but 4 is just over 10% less than the others