General SAFC out of tune?

[talontsi9095]

Well about 3 months ago i had a bad boost leak cause my intake mani. gasket was bad so i took it to my friends shop and we replaced it well i left it over night there and come back the next day to pick it up well ever since then when my car boosts to 1bar and it hits around 4000 rpms it feels like it studders really bad like i hit a wall sort of like a fuel cut. Well i got to lookin at my afc and my cor. on it i think has changed cause it goes down from 24% at 3000 to 23% at 4000 and about 20% at 5000 and it keeps droping from there at high throttle. Now is that wrong because i thought it should go up at higher rpms. I dont own a pocket logger right now and ill be getting one soon to tune it, but i was wondering if that could be my problem. The guys i had helping me with my car was messing with my afc for some reason i dont know why. Also the car boosted fine when i had the boost leak it would just leak after getting to full boost at about 1.4 bar.

 

[bmwisthekey]

your settings are probably too rich, youve got injectors, fuel pump and a fmic that should keep knock down pretty good on a 16g, get a logger and see where you stand and figure out if you need to take some fuel out of the high settings on the afc thru the rpm range, also wouldnt hurt to test for boost leaks again.

 

[1993eclipseGS]

If you tuned the car, While having boost leaks, And then fixed the boost leaks.... Your tune is now off.

 

[talontsi9095]

No the car was tuned by the previous owner. I need some extra cash first before i can buy a logger so when i do ill let yall now somthing.

 

[1993eclipseGS]

Either way, If the car was tuned without a boost leak, But has one now, The tune is off.

 

[talontsi9095]

Ok guys this is a wierd one? I have been having a problem with my car that started after i fixed a boost leak which was in may. Well my car wouldnt boost over .7 bar after 4000 rpms it felt like i was hitting a wall i guess it would studder and not gain any more boost. Well tonight it is around 50 degrees outside and i got in my car drove about three miles down the road. I gave it boost and at 4000 rpms i floored it and it went to 1.3 bar and held! So my car was running great the entire time i dorve it tonight??? But i still cant figure out why the entire summer it was having the problem it had? Heres the link to one ofmy posts on the problem i had. http://www.dsmtuners.com/forums/showthread.php?t=236480

If anyone has a clue let me know thanx.

 

[talontsi9095]

Well another wierd one for yall! Today i went to school and in the morning when it was cool it boosted fine but later on when it got into the mid 70's it started having the problem again!!!!!

 

[kelvinb]

you said the car was tuned by the previous owner....did the previous owner not live locally by chance? may need a retune..

 

[chickmagnet]

Different weather will need a different tune.

 

[talontsi9095]

Well i the car was tuned before i bought it last summer i drove it all summer and winter until i got my tranny built then my intake mani gasket went bad causing a major boost leak well after it was fixed my other problem started happening it doesnt feel like a normal boost leak it feels more like the BOV is kicking the car around but it will hold boost past 4000 rpms but if i give it more than .7 bar it will studder really bad. But last night it hit full boost with no problem and i made a couple of passes up and down the street. Then again to day after it warmed up it started up again?? The guy i bought it from lives about 600 miles away and i dont think its the tune really. Oh when i mean studder it feels like a fuel cut kind of it hits that wall past 4000 rpms.

 

[talontsi9095]

Well i think im goin to do another boost leak test but if yall have any other ideas then let me know.

 

[slipstream808]

I hate to be the bearer of bad news, but if a problem just "fixes" itself, than we wont be able to help you if you have no idea what was wrong before.

You my friend need to get a datalog up. Or even better yet, get that DSMLink.

We're gonna need more info. How's the boost controller? I'm guessing you have the stock MAS?

 

[crankbender]

A little more information would be helpfull.

What gage are you using for boost?

What does the stock gage read?

What is your throttle like?

When you say the car stutters what do you mean? Does the car just stop? Does it stop giving more power? Does it litteraly stutter and lurch?

This will help us a bit.

 

[talontsi9095]

A little more information would be helpfull.

What gage are you using for boost?

What does the stock gage read?

What is your throttle like?

When you say the car stutters what do you mean? Does the car just stop? Does it stop giving more power? Does it litteraly stutter and lurch?

This will help us a bit.

Im using a greddy boost gage that reads it in bar. Stock gage i have no clue what it reads. the throttle is normal i guess i can give it full throttle until it gets up to 4000 rpms and when it gets close i have to let off until im only giving it .6 bar of boost. If i go above .7 bar thats when it starts to stutter. Well when the car stutters it only happens around 4000 rpms and the car hits .7 bar it will not go above .7 bar and and the car literally just stutters at that point if you take your tongue and make a stutter sound thats the best way to describe the sound. Like i said though at night when it cools off to 50 deg it started running more normal it would boost all the way up to 1.3 bar? The boost controller is a manual under the hood and it works good and it does have a stock mas. Well hope this is enough info for some help but if you need more just let me know.

 

[talontsi9095]

Here is the bolt on mods to my car.

RC 550 Fuel Pump Hawn upper intercooler pipe Griffin front mount intercooler Custom forcedperformance lower pipes Poly motor mounts Greddy Type S BOV Ingen intake 16G Turbo RRE down pipe RRE test pipe Thermal 3 Inch cat back Apex AFC Greddy Turbo Timer Greddy Boost/EGT gauges Ported 2G exhaust manifold B&M Short throw shifter Welded center diff ACT 2600 ACT Street light flywheel and now a TRE tranny with galant 1st and extended 5th gear

 

[slipstream808]

Well then. I'd say check your plugs and wires.

No boost leaks I'm guessing? Take that leak test up to 25psi.

 

[talontsi9095]

I have done changed the plugs and the wires and checked the gaps all was good there i need to make a trip to lowes to build a boost leak tester.

 

[talontsi9095]

bump still need help

 

[redeclipse7782]

It appears your car is running too rich. I love how people have cold air intakes, and intercooler but don't understand the principles of how they work. Colder air means more oxygen, more oxygen means more fuel, more fuel and more oxygen means more power. So when its cold out you have a better air to fuel ratio because you are sending more air into the engine to burn with the amount of fuel you are sending. When its warm outside you are sending less air, but still the same amount of fuel so you are running rich. You are still probably running rich when its cold outside, just not as much.

Too much fuel you loose power, too little fuel you loose power, this is why tuning is so important. If you don't know how to tune get a wideband and learn, if you are too lazy to learn bring it to a dyno and have them do it. People are amazed how much tuning makes a difference through power increase and smoothness of the engine.

"All cold air intakes operate on the principal of increasing the amount of oxygen available for combustion with fuel. Because cooler air has more density for a given volume, cold air intakes generally work by providing cooler air from outside the hot engine bay. However, the term "cold air intake" is often used to describe other methods of increasing oxygen to an engine, which may even increase the temperature of the air coming into an engine."

 

[talontsi9095]

Well i wasnt having this problem last summer and it still has the same tune. Though would running to rich cause the problem with it stuttering like it does??