Running rich?

[Alex Pakhotin]

Got the following graphs last week:



The guys at RG said it's running rich, but it's kind of normal for the stock cars.
After some reading I tend to agree it's rich, as most DSMs seem to run usually with AFR at around 11, not lower than 10.
What AFR do you guys have?

If it's rich, what are the standard points to be checked? Spark plugs, O2 sensors, MAF, boost leaks?

As I mentioned in my other thread, I had CEL with error P0170 "Fuel trim bank 1". Does it give any clue? It appeared previously, I reset it and haven't seen for a while.

I have an OBDII reader (Bluetooth ELM327). Can it help to diagnose the problem? What software could I use and what parameters should I check?

I continue searching the DSM forums, but any useful information will be appreciated.

[Rob Armstrong]

Check for boost leaks. You need to know that first.

[daniel Dee]

Hack your MAF to lean it out.

[Jason Harwood]

The code means your long term or short term fuel trims are off.

Do basic maintenance, plugs, etc.

If that fails - buy a chipped ECU with a map from Jeff G so its leaner and get more power.

When I had my 2G it was super rich to begin with.

After an ECU it was 11.7's after tuning... 12.2 afr's.. so a little leaner. But it was still safe on my setup.

[CamWeiss]

You mean Jeff O?

'Cuz he's done with making chips.

[Vlad Busta]

Check if one of your O2 sensors is toast. Yes the stock fuel tables are rich. I believe the 1g maps can go as soon 9.6afr in some spots stock.

Later, Vlad.

[Alex Pakhotin]

Check for boost leaks. You need to know that first.

OK, this was already on my ToDo list, so I started with the leak test. Constructed a boost leak tester as described here, and did some tests today. Found that my MBC was leaking like crazy. I heard many of them leak by design, which is not a good thing I guess. Mine is a cheap "Made-in-Home-Depot" one:



Well, removed it for now, back to stock boost.

I didn't have a good compressor, only a small 12V-powered from CanTire. Apparently it's too weak - it doesn't have enough performance to push the pressure to more than ~5 PSI. But at least I haven't found any other apparent major leaks.

Need another dyno test now.

[John Hartman]

the small leak at the side of the body of the controller is normal and has to be there.  that little won't cause much of an issue if at all.

borrow a better compressor and test it out.

[Alex Pakhotin]

the small leak at the side of the body of the controller is normal and has to be there.

OK, I knew it's kinda normal, but wasn't sure how much leak is allowed to be there.

that little won't cause much of an issue if at all.

I don't know what is considered little. It was a very noticeable blow. Anyway, I've removed it to try, and haven't yet found any other leaks comparable to this one at MBC.

borrow a better compressor and test it out.

Yeah, I'm planning to find one and do a proper test just to be sure.

[John Hartman]

the little hole in the boost controller is like the size of a sewing needle.  Thats it.  If its leaking from any other part of the system its bad.  Only that little bleed hole.

[Vlad Busta]

Remove the boost controller when testing for boost leaks. Then put it back in afterwards. The leak. In the boost controller is normal. That bleed hole prevents the wastegate from being stuck open between shifts I think.

Later, Vlad.

[Lowell Foo]

A lot of boost drop off on your graph.  I boost leak test at 50% higher than system pressure, so a car that runs 30psi, I will test at 45.

[Alex Pakhotin]

OK, found some leak here:





What is that thing? Ignition power or something else? Can someone tell what leaks there, and what needs to be fixed? Is that some kind of an insulator, which needs to be replaced?

[John Hartman]

the round thing with the two prong connector is a fuel injector.  The leak is from the lower seal.  They are fairly cheap, but to change them, you need to remove the fuel rail(silver tube that goes across all 4 injectors.  Not super hard really, but there will be a fair amount of fuel spilling out when you first open it up.

[Alex Pakhotin]

the round thing with the two prong connector is a fuel injector.  The leak is from the lower seal.

Aha, I see. Are there seals in the manifold, plus O-ring seals on the injectors themselves? I guess it's better to replace all of them.
Thanks!

They are fairly cheap, but to change them, you need to remove the fuel rail(silver tube that goes across all 4 injectors.  Not super hard really, but there will be a fair amount of fuel spilling out when you first open it up.

Yeah, I already guessed it will be pretty time consuming and dirty job.