help!!!! Why am I pulling timing???

[1fast97gsx]

Why am I pulling timing??!?! Please help me!!!! Here is a datalog:

rpm timing O2

3276 25 .96
3612 23 .96
3984 23 .94
4480 23 .94
5140 18 .96
5844 14 .94
6420 13 .92
6992 10 .92

I don't understand this at all .. I made some more minor adjustments to get the O2s closer to .92 and .94 but it still drops. My boost is at 23 psi on an scm61 turbo. I have a fmic and all other supporting mods and I'm still using the crap safc. My injectors are 780s. Full boost comes around 4600 or so. Could it maybe be an ecu problem? Everytime I launch it it just sputters and feels like I'm hitting a brick wall 50 times in a row or something. I had the launching problem as well last summer, however since then the engine has been fully rebuilt, different coipacks, plugs, wires, injectors, transmission, clutch, and a few other things. All I can relate all these problems to is the ecu. The car has some ghey "gforce" ecu on it which nobody seems to know what it does, but I'm thinking that's the reason for this?? I know the tuning is bad, but it doesn't seem like I should be getting a timing curve like that AT ALL. And I'm not new to tuning either ... I had the timing curve on my old 16g perfect and was doing mid 12s with it.

 

[98TsiAWD]

Are your LTFT's set properly? Any boost leaks, especially check the tb shaft.
What brand are those injectors, some are junk and dont flow evenly causing problems.

Are you getting knock when its puling timing?

 

[1fast97gsx]

yea a boost leak is what I'm thinking as well. I have my controller dialed in a 28 psi because that is the only way to make 23 psi. The problem is I can't find the leak ... even with the tester hooked up and 24 psi in the system I get no hissing. ( or at least I don't hear it ) My injectors are precision injectors.

 

[1fast97gsx]

not sure about knock since I have no way to read knock count, but thats what I'm assuming is why timing is being pulled. Unless its a boost leak?

 

[kpt4321]

What happens if you add fuel (and subsequently remove timing)?

 

[1fast97gsx]

I tried adding some fuel and the curve still went downhill. I don't understand ... timing is dead on and it's non adjustable ( 97 gsx ) so I can't be doing that wrong. My boost can't be too high either to be causing this since I've heard of people with higher compression even running more boost. My guess is a boost leak now, but I can't find 1. ( I have my controller set at 28 psi just so it makes 22-23 psi.

Another thought ... instead of a boost leak, is it possible that my lines running to my external wastegate are just too small??? Sounds dumb, but maybe it's opening early because not enough pressure from the lines can get in to hold it closed??

 

[1fast97gsx]

something else I though I would mention ... my intercooler piping is ghetto and small. it's 2.25 to the intercooler which should be fine, but then from the intercooler to the throttle body its only 2.25" as well and it's long route. Could this be another reason why I'm losing boost? All these problems are driving me nuts!!

 

[Turbo Monk3y]

Well i do know the long route piping will not make you lose boost if you have no boost leaks all the short route piping does is help throttle response. And if you have 2.25" intercooler piping to a 2g throttle body that mates up pefectly. If you have a 1g throttle body then i would go 2.5" from the outlet of the FMIC to the throttle body... as far as your boost problem goes i have no idea... Maybe a squirrel ran up into your exhaust and died causing you to have a restriction in exhaust flow ????

 

[ahains]

I am familiar with GForce chips from the MR2 community - they are tuned for very aggressive timing and leaned out fuel.
I would assume they do something similar for a DSM.

Given that you have very big injectors, you are probably trying to lean them quite a bit thereby getting too aggressive of timing and siginificant detonation & timing pulled.

I am still a DSM newbie so maybe I'm wrong here, but isn't your timing kind of extreme at low rpm? This isn't necessarily a bad thing in general, but just makes me assume that you are in fact doing some heavy SAFC adjustments (seems reasonable).

Why don't you turn down the boost a lot, maybe throw in some toluene while you're troubleshooting, and see what happens? I'm thinking you may need to get rid of that GForce if you want to run big injectors.

HTH!
Adrian

 

[1fast97gsx]

I am familiar with GForce chips from the MR2 community - they are tuned for very aggressive timing and leaned out fuel.
I would assume they do something similar for a DSM.

Given that you have very big injectors, you are probably trying to lean them quite a bit thereby getting too aggressive of timing and siginificant detonation & timing pulled.

I am still a DSM newbie so maybe I'm wrong here, but isn't your timing kind of extreme at low rpm? This isn't necessarily a bad thing in general, but just makes me assume that you are in fact doing some heavy SAFC adjustments (seems reasonable).

Why don't you turn down the boost a lot, maybe throw in some toluene while you're troubleshooting, and see what happens? I'm thinking you may need to get rid of that GForce if you want to run big injectors.

HTH!
Adrian

Yea actually I put in my 95 eprom ecu today and made some more safc adjustments. My timing curve looked MUCH better.

So I guess ... gforce = crap?

 

[EVIL X]

Newer Knock Sensor?? I Had A Similar Prob On My 95, And It Ended Up Being The Sensor Itsself

 

[1fast97gsx]

I knew I shoulda replaced it ... it's still my stock 97 with 63k on it. I might replace it just to be safe .. although the ecu seemed to help a lot.

 

[ahains]

Yea actually I put in my 95 eprom ecu today and made some more safc adjustments. My timing curve looked MUCH better.

So I guess ... gforce = crap?

For your application, yes.
If you are running a stock fuel system, a gforce should (probably) work great.
-Adrian