2G black smoke ?

[Inkdlyfe]

What all would cause black smoke ? I noticed it only really does it when I use 93 gas not 89 but I was told not to use 89 unless I had to but there really isn't much difference in proformance... Turbo 420a with 28psi of fuel 430 injectors I believe

 

[chiefvest]

Black smoke typically means you're engine isnt burning the fuel completely. You either got some bad/dirty fuel (doubtful since it sounds like youve been getting new gas often) or have a problem with your emissions system, usually a bad oxygen sensor

 

[Inkdlyfe]

Well a bad o2 would throw a code ? I don't have a code for a 02 sensor but I also have a egr delete would that be the reason ?

 

[chiefvest]

Yes usually a bad 02 would throw a code. Do you have a CEL on at all? The egr valve recirculates exhaust through intake. Black smoke is usually a sign of a rich condition possibly amplified by the egr delete. Lower the octane again and see if it improves.

 

[lasershark]

Fill out your profile, especially on a 420a turbo build car. We have no idea of knowing anything about your car which makes trouble shooting difficult.
What are you tuned with?
28psi of what? Fuel pressure or boost?
What are your fuel ratios like? especially under boost
What is your compression ratio?
Fpr? Fmu?
Black smoke as said above is indicative of running rich, it is also not really recommended to lower the octane on a boosted car.
http://www.dsmtuners.com/threads/welcome-to-dsmtuners-now-go-create-a-dsm-profile.499707/

 

[chiefvest]

Any updates or fixes to this issue?

 

[Inkdlyfe]

Any updates or fixes to this issue?

Not much of a fix but I noticed that my car was set at 38 psi of fuel I turnt it down to 28 and now there isn't much black smoke but I've also found out that my 4th port injector is staying open which is more then likly the cause of the black smoke problem

 

[gdb1039]

Some one correct me if I'm wrong but isn't the fuel pressure on a 2g supposed to be at 43 psi? Seems like running 28 psi of fuel pressure would make your car run really lean.

 

[Inkdlyfe]

Some one correct me if I'm wrong but isn't the fuel pressure on a 2g supposed to be at 43 psi? Seems like running 28 psi of fuel pressure would make your car run really lean.

Same thing I honestly thought but when set at 38 psi it bogs down and wants to die off it actually still runs rich at 28 psi.. Thinking thats die to the injector problem leading me to this other post

http://www.dsmtuners.com/threads/perfect-injectors-for-a-turbo.502166/

 

[gdb1039]

If you have a injector suck open then you need to fix the injector. Turning down fuel pressure is a quick way to destroy your motor do to running to lean. As for your other post do you have a way of tuning the car? If not you still need a tuning device before putting in bigger injectors. If this is the case best best would be rebuild our replace with same size injectors. If you have a data logger post up a log. I'm still learning logs but I'm sure one of our more experienced tuners on here could help you out more.

 

[Inkdlyfe]

If you have a injector suck open then you need to fix the injector. Turning down fuel pressure is a quick way to destroy your motor do to running to lean. As for your other post do you have a way of tuning the car? If not you still need a tuning device before putting in bigger injectors. If this is the case best best would be rebuild our replace with same size injectors. If you have a data logger post up a log. I'm still learning logs but I'm sure one of our more experienced tuners on here could help you out more.

I know turning down the psi can harm I'm not blow the engine yes but even at 28 psi I still run extremely rich and never lean not even at a idle or a deaccel. The only time I see lean is when I hit 4k rpms it's like it hits a wall and shuts down but only at 4k. And only 3rd gear and up 5th is the worse

 

[Inkdlyfe]

So I just shift at 3.5 and it drives perfectly fine no black smoke nothing

 

[Inkdlyfe]

May I add it only hits a wall feeling while moving I can hit 7k easy no problem at a stand stil

 

[ThunderChild]

its not reading rich at that psi because you have one injector stuck open and the other 3 are being compensated for it. so they are running extremely lean. stop driving the car, fix the injector, and turn the fuel pressure back up to spec.

right now youre just band-aiding a serious issue. also, fix any boost leaks and/or exhaust leaks.

 

[Inkdlyfe]

So what is the right psi to have my fuel set to for a daily driver ?

 

[ThunderChild]

Being that you're a 420a turbo, and it sounds like you have a return style fuel system, that is a hard question to answer. Generally 38-43psi is a good base pressure with an AFPR. But it will depend on you injectors, how you control fuel and spark, and what your afr, knock and boost pressure are dynamically. Truthfully, you need to fix the problems you have, then get the car tuned. If you can't tune it yourself, take it somewhere and have them tune it.

 

[Inkdlyfe]

Alright sounds like I might just have to hop it to 38 and then fix what I have to fix. Thanks for the help man

 

[1990TSIAWDTALON]

A open injector would make the fuel pressure fall off since it is basically a hole in the pressurized system. Does your fuel pressure go to zero almost as soon as you turn the car off? Most will hold and gradually bleed down.

 

[chiefvest]

Please do. Id hate to see you blow the motor or melt a piston. Dsms already get a bad name as is haha

 

[Inkdlyfe]

A open injector would make the fuel pressure fall off since it is basically a hole in the pressurized system. Does your fuel pressure go to zero almost as soon as you turn the car off? Most will hold and gradually bleed down.

It stays at 38?? Only drops when let off the gas but only lets off maybe 5 psi then goes back up

 

[Inkdlyfe]

So maybe it's not opening ?

 

[ThunderChild]

he means does the pressure go to zero when you shut the car off, or does it hold pressure for a little while?

 

[Inkdlyfe]

See if where going to go off what your saying then the car has no problems... Like when I start the car it dies but then I start the car again right after as long as I help it warm up it don't die (iac problem I'm sure) and will stay running but seems like it might have a slight miss fire (or exhaust leak maybe) but my fpr stays at 35 psi WOT 38psi and when let go of throttle it drops to about 30 psi but then goes right back to 35psi but I have a cell for my 4th bank injector malfunction.. Another thing I noticed that is still doing it it seems to but a wall at 4000 rpms in thinking it's tied into all this tho.. Mind you when I got the car it ran very strong now is doing this

 

[1990TSIAWDTALON]

Ever thought of pulling the injector plug off of #4 when its running to see what kind of difference it makes. The CEL is trying to tell you something. You could do a cylinder drop test, pulling the injector plug off of each injector while it runs and record what the rpm drop is then move to the next cylinder and so on (something you would usually use an engine analyzer/osillascope to do but it still works the same). It would give you some feedback on what is going on.

 

[ThunderChild]

You're not understanding. After the car has been running, when you shut the car off (turn key off and remove from ign), what does the fuel pressure do? Does it hold pressure for a while or does it drop to zero very quickly?

You already know you have an injector problem, so it's either the injector itself, the resistor box thats been put in, or bad wiring somewhere.

Your idle/starting problem is another issue, and you're probably right that it's the IAC. You should test and fix that soon or first.