High EGT's

[bacalhau16]

I just installed my FMIC, I was taking it for a beat run on the highway, and the EGT's got pretty high. I had to let off because my EGT guage went to 9k C. It seemed like it was running a little lean, but the autometer Air Fuel guage isnt exactly accurate. I tried to add fuel with the S-AFC, but didnt seem to do much. At one point the check engine light came on, and the car would not boost. Just not very excited about this. The car was not overheating and idle ok after the check engine light shut off.

 

[joe]

Have you done a boost leak test yet? also find out why your check engine light came on

 

[knochgoon24]

I doubt you hit 9k C. Steel melts at 1.5k C.

I think you mean 900 C.

 

[bacalhau16]

Sorry, yes I did mean 900C. 9000 would be pretty high. I cant believe that the car could actually be running lean. It has 660cc injectors, a walbro fuel pump, AFPR, and only a 14b at 15lbs of boost. I will have to do a boost leak test I guess, but I really dont think it is. I couldnt see how. I know all my couplings are tight.

 

[snox135]

What are you using to control the bigger injectors? If you are not using anything your egt's may have been reading high cause you are running extremely rich.

If you were creating boost when it was running the high egt's and you have a boost leak. Then you were running rich at that time. Which could also cause the egt's to read high from the unburnt fuel burning in the exhaust manifold.

 

[bacalhau16]

I have an S-AFC to control the injectors, and a 2g maf. Im not following though. If I had a boost leak, would it not be reading a lower boost. Im still running the same 15lbs of boost that I was running before I installed the FMIC.

 

[snox135]

It may or may not affect your boost pressure, depending on the size of the leak.

 

[2gGSX]

Many things affect EGT, with timing being a bigger factor than AFRs. The shift from 9.5:1 to even 12.5:1 does will not compare to knock and/or base timing being off. If timing is retarded, the entire air/fuel mixture will be less combusted by the time it leaves the exhaust port, meaning more partial combustion within the exhaust manifold itself.

Have the CEL checked out and find out what it is.

 

[bacalhau16]

The CEL shut off while driving home. It was sluggish for a minute or two and bogged like crazy if you got on the gas hard, but it went away. No CEL now, drives fine. I havent really gotten on it too much since then, havent had the time. I want to go dyno this week. Hopefully this will have most of my answers.

 

[bacalhau16]

This high EGT thing is pretty annoying. I can not complete a 4 gear pull without my EGT reading 900C. Im just not entirely sure that it is actually going that high. I have 660cc injectors, a fuel pump, and an AFPR, so I really dont think I could possible be running out of fuel.

Perhaps it is too rich, but I tried taking away some more air, but it did not seem to do much.

 

[TjPhillips36]

In your first post you mention you have an autometer air/fuel gauge? I'm assuming this is a narrowband? If so trash it and get a wideband to measure your air/fuel ratio. From the sounds of it your are running real lean. Do you have any sort of logger to help show some data on what is going on in your engine? If not, I would invest in some sort of logger too.

 

[Team Addiction]

Dont waste your time tuning with a narrowband its pointless!

Also EGTs can be very tricky as high EGTs often have little at all to do with fuel. Im assuming the 4th gear pull is WOT? therefore you are under high load and probably need to pull a little timing.

Point is dont always look at fuel when EGTs get high as timing can very often be the real culprit. Although in this case attempted narrowband tuning may be the real cause.

 

[bacalhau16]

I dont put any real trust in the autometer guage, I know its garbage. I actually do have a datalogger for my car, but the batteries dies in the palm pilot, so now I have to go and redo the whole thing.

My thing is, if I go to the dyno, I should pretty much be all set. If it reads rich, then I will pull fuel. If its lean, then I will add. But if Im right around 11, then I need something to take back a little timing.

I just cant see that adding a FMIC really changed my setup THAT much, where I can just mess with the fuel a little with the S-AFC.

 

[TjPhillips36]

What kind of turbo are you using?

It's possible before the front mount was installed the car was pulling timing due to knock, but after the front mount the reduced intake temps helped reduce knock and now you need more fuel.

The only real way is to check data logs. And just going to the dyno and adding/subtracting fuel with a air/fuel meter is not going to help if it is something to do with timing. Go get some batteries and run a log and see what is happening inside your motor.