Need help with timing and tuning questions for a 2G

[kristmen]

Well first off, I own a 1G and I've pretty much got tuning down but my friend finally bought a PocketLogger for his 2G because it kept throwing check engine light codes and we needed to know why.

The car is question is a 1998 Mitsubishi Eclipse GSX AWD Turbo Automatic.

His car is pretty stock but has a few mods.

Big16G Ported with 34mm WG flapper, EVO 3 O2 housing, 3in turbo back with no cat, Greddy muffler, Walbro 255 LPH, AFC2, K&N air filter and a Turbo XS H-RFL BOV.

Now the engine was a rebuilt less then 10,000 miles ago and has J&E pistons. Now the owner says they are 9.0:1 and I'm not sure if they are oversized or stock bore but it came from Advance Auto. Me and my other friend who is also a 16 year machanic think this is wrong and its more like 8.5:1 but we are going to contact the rebuilder "Recon" and find out for sure on Monday.

Engine has the balance shafts removed and also the trans was rebuilt less then 20k ago too.

Ok on to the questions.

First thing we noticed was a code for the throttle position sensor which we already thought might have issues. The next code was for turbocharger waste gate but we figured this was due the fact the factory electronic boost controller is disabled.

We took the car out and made a couple pulls and the timing was like 4~10 and the EGT's were hitting 1700+. The o2's were like .96..

We came back to the house and got into the DSM channel on dsm.org and a couple people told us the issue was the car was way to rich which was pulling timing and the fuel was burning in the manifold which was causing the EGT's to be so high. Everyone awake seemed to agree we needed to lean out the high map.

We went back out, leaned it to -5% on the AFC gave it a couple more pulls and got the same results so we went to -10% from 3600 to 7600 in the high map and the car got a bit faster but this time the timing hit -4 so we went to -15%, then -20% on the afc and both pretty much still had use in the 6 to 10~12 timing ranges. Almost all these pulls had us around 1700+ EGT's no matter if we leaned it out or richend it up.

Boost is 16 PSI due to injectors still being stock 450's.

What are we doing wrong?

I will post a couple logs from tonite when I get home to my PC and maybe someone can look them over.

 

[CanadianTSi]

Amazing that you didn't blow it up....

-20% fuel with the stock injectors , If anything you need to be adding fuel.

Put the S-AFC to 0 and keep the boost at 15 or lower until your friend gets some bigger Injectors.

 

[Blk_99gst]

Amazing that you didn't blow it up....

-20% fuel with the stock injectors , If anything you need to be adding fuel.

Put the S-AFC to 0 and keep the boost at 15 or lower until your friend gets some bigger Injectors.

Yep, Canadian hit it right on the head. There's no reason for you to be leaning out the stock injectors. The stock injectors and the ecu will work fine together, so going 20% leaner using a piggy back control is not necessary.

 

[kristmen]

Still doesnt tell me what the hell is going on.

And the guys in #DSM still say too rich due to the bigger pump.

Going + correction didnt help eather. Still the timing is like 6 or so.

 

[Blk_99gst]

Well first off, you kind of need to know your car that you're dealing with. From your first post you don't even know the internals of the engine; if it's 9.0:1 or 8.5:1, if it's stock bore or oversized. If you are running a different compression ratio it can totally throw things off or things will knock easier.

And as far as the guys in #DSM saying you're running rich; you could easily search for "bigger fuel pump make me run rich" and you would get a lot of info at your finger tips. A bigger pump can cause overrun with the stock fuel pressure regulator, so some people may be rich at idle or have problems tuning at idle. But normally at cruising speeds or at wot, it's not a problem because you're using a ton of fuel and the stock fuel pressure regulator is fine.

No offense, but you don't know enough about tuning to be adjusting the safc -10, -15, or -20%. That will eventually blow your built motor. And don't do it just because some people on the internet tell you too.

 

[kristmen]

Well its not even my car. I own a pretty well modded 1G and I'm running 20 psi. I know my car inside and out. This 2G is another story. I'm lost. I finally had to get a 2G PocketLogger just to try to get an idea and I'm still lost.

You are right though. I dont know shit about this engine. All I know is that its a Recon rebuilt from Advance Autoparts. My friend seems to think its 9.0:1 but that doesnt seem right. I'm thinking maybe 8.5:1 at the most.

Yes I know high compression and high boost dont mix which is why I'm wondering whats going on with this car.

I do know I boost leak tested it and found out he has no gasket on his J-Pipe so I'm installing one and going from there.

I'm trying to figure out a way to find out the engine spec's. Prolly have to call Recon.

Also I wouldnt have thought to lean it out eather but everyone seemed to agree on trying to lean it out. I also know to lay off the boost when its leaned out so I'm not too worried about blowing it up. I wouldnt go out boosting alot until I figured out what was wrong anyway.

Thats what I'm trying to do. Figure it out.

 

[hostile]

Log TPS. If the tps isn't working fix it before you try and tune.

When important sensors like the TPS are missing the ecu will do certian things to keep the engine safe.

I bet in your case it is retarding the timing because there is no TPS signal.

Fix everything that is wrong with the car before you try and tune it.