Car is laying over in 3rd....need some ideas...log attached

[krom]

I think that 8.5 AF is a problem. You have pulled 5% already and are still pig rich. Your AF was fine until 29.458 then it goes rich and stays there. Are you injecting at that point? I would take out more fuel at WOT and adjust your tps to a minimum of 4.50.

 

[trbojo]

What is your boost at when this happens? I had a similar issue where boost wasn't reaching the target that the fueling in the chip was set for... If this happens, you essentially flood the engine.... For example you spec a chip for 25psi and only hit 15... At wot the ecm is fueling for 25 therefore flooding the engine... I ask because of the header issue you mentioned....

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[Eric Stage I]

What you're seeing with the MAF is the MAF lock working. The lower reading is the actual MAF reading before its forced to 255. I don't think you have a problem with the MAF sensor.

What do you have for an intake setup? Is it possible you have an intake hose or filter collapsing?

 

[TurboBuRick]

If it were ignition related it would also make the afr's spike. Strange that the afr's don't seem to move at all. It almost appears as if something blocks off the intake. Air cleaner collapsing? Or some part of the intake?

Eric beat me too it.

Rick

 

[Amelio]

I think that 8.5 AF is a problem. You have pulled 5% already and are still pig rich. Your AF was fine until 29.458 then it goes rich and stays there. Are you injecting at that point? I would take out more fuel at WOT and adjust your tps to a minimum of 4.50.

Are you referring to Log #2 or #3?

I also assume you are referring to the ECM AFR......I am actually unsure how the ecm calculates this.......I always watch my WB AFR's which never drop below 10.3

I was under the impression that the WB AFR's are more accurate and that is what I usually tune to....am I wrong?

If I am wrong then you are right, it is pig rich and its flooding out!

 

[Amelio]

What you're seeing with the MAF is the MAF lock working. The lower reading is the actual MAF reading before its forced to 255. I don't think you have a problem with the MAF sensor.

What do you have for an intake setup? Is it possible you have an intake hose or filter collapsing?

Thanks for the explanation of the MAF Eric!

I have a 9" K&N cone and 3" aluminum piping all the way to the turbo with big heavy duty rubber connectors.....I am also running an LS1 MAF in there.

This is the setup I have been running for years.

Now a few weeks ago I replaced my alternator and then went for a drive and the problem started.......when I pulled over I noticed I left the clamp to the boot on the turbo loose.....I tightened it and it and it fixed it on the way home. I got in the car the following weekend and the problem was back.

Now I have to say when I pulled 5% of WOT fuel out, the car woke back up in 1st and 2nd but falls off in 3rd........I have had problems in the past where a rich condition makes this car a turd!

Now back to my previous statement.....do I follow the ECM AFR or the WB AFR ( which is a PLX )?

I don't want to pull any more fuel out based on what my WB is saying.

This chip is set for 18psi and as you see the car is hitting 17-18 and levels off at 16.........do you think it is just fat? If so I would have to blame that on the hot air and or the exhaust leak......would the exhaust leak cause a rich condition? I can see it causing one down low as the car see's higher TPS volts but due to loss of pressure it does not spool causing a rich condition but the car does great 1st and 2nd and by the time its in 3rd the exhaust leak should not matter as the car is spooled up....is my thinking off?

 

[aminga]

Are you referring to Log #2 or #3?

I also assume you are referring to the ECM AFR......I am actually unsure how the ecm calculates this.......I always watch my WB AFR's which never drop below 10.3

I was under the impression that the WB AFR's are more accurate and that is what I usually tune to....am I wrong?

If I am wrong then you are right, it is pig rich and its flooding out!

He may have the wideband set wrong when looking at the logs. When I read it in (with a PLX WB) it looks close

It would help to have the build in your sig

 

[krom]

I changed to PLX and the WB changed to 10.30, still a little rich. It was log 2. Your O2 also shows rich in the 820-830 range. I tune WB around 11.3 to 11.5 and O2 at 775. I would try to take some WOT fuel out. I always follow WB numbers over the narrow band O2.

 

[Amelio]

I just ordered a new set of gaskets so I am going to correct the exhaust leak at the crossover pipe this weekend and see what type of change it makes.

It very well may just be fat....since it was having an issue in 1st and 2nd until I leaned it out......then it picked.....I have never had this car be so fat that it falls off like its doing....it has been fat in the past and just spits and sputters.....it may be a very easy fix in the fact that its rich.

Have any of you experienced a rich condition due to an exhaust leak?

If it is a rich condition and the exhaust leak does not correct it then the only other thing causing it is the hot air temps????

 

[Ttype6]

Have any of you experienced a rich condition due to an exhaust leak?

An exhaust leak won't effect wide open throttle fuel.

 

[Amelio]

An exhaust leak won't effect wide open throttle fuel.

I didn't think so....

With that being said...if all else is good and it is just a rich condition...then the only thing left to cause it would be the hot air temps.........

 

[earlbrown]

Actually, if the exhaust leak causes the boost to be low, it can affect WOT fueling. If the chip is spraying enough fuel for ''X'' amount of boost and you're flowing less, you'll end up rich. (and fat during the slower spoolup stage... which will, kill spool.... etc...)


That's why we used to tune with fuel pressure back in the old days before translators and adjustable chips

 

[Amelio]

Actually, if the exhaust leak causes the boost to be low, it can affect WOT fueling. If the chip is spraying enough fuel for ''X'' amount of boost and you're flowing less, you'll end up rich. (and fat during the slower spoolup stage... which will, kill spool.... etc...)


That's why we used to tune with fuel pressure back in the old days before translators and adjustable chips

I agree with you Earl....and I felt it would cause a rich condition especially on spool up which would slow the spooling even more.......so maybe to TType6's point....the leak has no effect at WOT but my questions is referring to your point.....what about all the fuel being dumped into the engine while spooling?

If you watch the log the car is seeing WOT for way too long before it spools....this throws off my thinking because it rips the tires off 1st and 2nd and falls off in third........however it only started to run good in 1st and 2nd after I pulled out 5% fuel.

I need to fix the exhaust leak and set my fuel back to base and see what the car does........as I said the car has been flawless for the past 2 years since I rebuilt the engine.......If its still acts up after the leaks are fixed I will start leaning it out and see what happens.

 

[earlbrown]

I'd quit tuning around the exhaust leak and fix it. You'll end up having to tune it all over again when you seal it up.


Plus if there's an underlying problem that's not the exhaust leak, you don't know it until you fix the leak.

 

[Amelio]

I'd quit tuning around the exhaust leak and fix it. You'll end up having to tune it all over again when you seal it up.


Plus if there's an underlying problem that's not the exhaust leak, you don't know it until you fix the leak.

That's exactly what I am going to do Earl......I ordered gaskets from Jason at RJC last week.....I will replace them and set my tune back to base and start over.....

I will keep you guys posted as to what the car does after I fix the leaks......thanks for all the input!

 

[Amelio]

I found the problem!!!!

I just thought I would give you guys the rundown on what I found.

I got the new crossover and turbo flange gaskets last week from Jason at RJC.....as I mentioned I wanted to fix the known issues (exhaust leaks) first.

When I was unhooking my down pipe for removal I noticed the waste gate arm felt weird when I unhooked it.

A few years back I removed the waste gate arm and puck to drill open the hole that it runs through in the down pipe....it would frequently build up and get stuck......I then welded it back up.....

With that being said the weld was starting to fail so the puck would move independently of the waste gate arm. As soon as I saw that I knew that was my problem!

As I stated the car acted like someone just shut off the power.....I went through everything on this car and could not find the issue.......

Well I replaced the gaskets at the cross over flange and turbo flange and cleaned up and re welded the waste gate arm....took it for a drive and BAM!!!!!! tire ripping spoolage!

Thanks for every ones suggestions!

These cars sure can make you bang your head against the wall but when they are right it sure is rewarding!

 

[OhioC5]

Do you mean the puck was about to fall off? Did I follow you right?

 

[Amelio]

Do you mean the puck was about to fall off? Did I follow you right?

Something like that......if you look at your waste gate arm the stem of the puck is welded to a small plate which has another small stem that the accumulator rod hooks to....... basically the puck stem would rotate inside the plate.

It was not completely broken...if it had been then zero boost would be made....it was odd in that it worked in 1st and 2nd and as the load increased in 3rd the pressure would push the puck away as the accumulator rod held it shut.

This was very hard to see, it was not obvious at all and the only reason I saw it is due to me removing the down pipe to replace the turbo flange gasket........this was a first for me....much like most of the problem I encounter

 

[OhioC5]

Ok, I was just curious because my wastegate puck fell off.