SR20DET Performance Problems

[eXc]

Gday Guys, I am posting this up for a friend (username Footy) As he doesn't have net access at work, and wants to get some ideas so he can fix the car before the weekend.

93 180sx sr20det

with usual mods: zorst,pod, cooler, and a few others.

basically it has no power, turbo boosts fine guage shows heaps of boost in the manifold, but the car just doesnt pull hard. heaps slower then a standard 180sx when i am running .9 bar. it bogs down slightly after u shift but after that revs normally but is just gutless, doesnt miss or spluter doesnt blow noticeable amounts of smoke.

things i have tried:

replaced fuel pump/filter and fuel reg.

check intercooler pipes for leaks etc.

replace ego sensor.

replace afm.

compression test engine 150-160psi on all cylinders.

replace spark plugs.

adjust ignition timing.

clean air filter.

i am starting to think it could be a ecu issue. do these have a limp home mode or something like that which it could be in and if so how can i reset it?

i have a stainless zorst manifold which i have wraped with heat insulating tape, has anyone heard of this causing bad performance? i cant think of why it would.

any other suggestions?

thanks

Chris.

[slow13dude]

Hi,

Try posting on www.nissansilvia.com

[psybic]

My celica was similar to this when I first got it converted to 3SGTE. just ran like a dog for no good apparent reason. 62KW at the wheels in fact. on 7psi with exhaust and small front mount.

Microtech goes on, fixed up mixtures and got rid of standard dump pipe and AFM, but mostly due to the good tune possible once microtech was on...

125kw@wheels on 9psi.

so double the power, due to a better fuel mix. Have dyno sheets.

I'd be getting the fuel mix and timing checked out.

If you get someone who knows what they are doing to install a power FC, it will make ALL the difference.

The old ECU probably just is too old, some sensors are probably not running how they did stock, stuff like that, good tune will save the day and u need good ecu to do that.

[eXc]

Nissansilvia.com -> In my experience it's more hassle than it's worth. He is also a member there, I will leave it to him to post up there if he wants to.

psybic->

As far as I know, he has been running the car fine on this setup for atleast 1 year (closer to 2 I think)

He recently change the exhaust manifold, but I am pretty sure the rest has been the same for a long time.

So it is a problem that has just occured, seems wierd that its a fuel mix issue...unless the puta crapped itself.

Either way, I'm sure he will see your post tonight and consider it. I know he wanted to get it on the dyno, but didn't get the chance as yet. And we have the motorkhana on Saturday, so trying to sort that out, as ATM it stuggles to spin wheels in a slide apparently.

Cheers

Chris

[97Sky]

You cant seem to post anything at nissansilvia these days without every tom dick and harry bagging you out for something. Not worth the time IMO.

My 2 cents

[paulr33]

try ecu reset (disconnect power to car and pump brake pedal a few times).

try turning the boost down as well and see if that helps. 0.90 bar is a lot for stock ecu

[eXc]

try ecu reset (disconnect power to car and pump brake pedal a few times).

try turning the boost down as well and see if that helps. 0.90 bar is a lot for stock ecu

He had the battery disconected for a day, So I am guessing that will reset it? To my knowledge, he DIDNT use the brake pedal in this time.

I am pretty sure he has the issue on standard boost aswell...But I will let him respond to that.

If anyone has ideas, just throw them at us, cause we will try everything we can tonight as the motorkhana is tommorow.

[BHDave]

Check the cat. If the car has been lowered and the exhaust hits things then there's a chance the honeycomb is smashed and causing a restriction in the exhaust.

It could also be past it's used by date too and clogged up.

edit: I haven't seen an sr lose power with a SS manifold installed ever and i've seen a few installed.

[eXc]

Yeah we can't see the manifold being the issue, just it's the only recent mod he has done (Cept suspension, but one would hope that doesnt effect the engine! haha)

I never thought of the Cat. We'll have to check that out. THanks

[YBSLO4]

Check the knock sensor... its a common overlooked issue. Run an ECU diagnostics check... if it throws a code 34 then its farked. I've fixed a view after people have had the same problem you stated, and have tried changing everything like you did. If the sensor is rooted, it tells the ECU its constantly knocking and will retard your timing when below 4K as the sensor only works until 4k, then it will take off like it should after 4k rpm. Make sure you do the ECU test correctly as if you don't you may accidently reset it before you do the test and it wont throw the code if you do that, and you will think its fine. Nissansilvia has a articles section on how to do an ECU check.

[YBSLO4]

Moreover, check that the base timing was set correctly and not to retarded. If you don't disconnect the TPS while car is idleing, and then rev it passed 2k rpm 3 times with it disconnect, the ECU wont go into 'set timing' mode and you wont have the right timing. When doing it to, don't use the timing loop its useless, you need to pull out coil pack number 1 and run a spark lead from the spark plug up into the coil pack and connect the timing sensor to the lead to get an accurate reading.