New/Current Issue:
Ok, so got the car to idle and idle fairly good. Parts that got changed were the front 02 and plugs since they were fouled beyond belief. The mechanic put stock plugs in and gapped them to stock. Issue seems to have been the hole in the UICP. Still a little rich, but have a new issue. Car backfires an hesitates slightly at idle, but is more apparent as you start to throttle up and move. Also, as a test, while logging, I put full throttle in for 1000 revs from 3k to 4k. AFR's seem to be right on with what is in the map and what is logged. Knock is around 6 counts, fluctuating from 4 to 6 to 5, etc and you can feel the hesitation and some backfiring. I know it is not safe to boost, and only trying to get a small amount to possibly see where the issue may ly. Tune wise, remember I had tuned it myself with recomendations from members here, and had it running rather stable at 22 psi. No change in the ROM has been performed yet. I am lost. More help please and thanks for the help with the initial issue.

Initial Issue:I took my car in to have the Turbo replaced(nether stocker, less miles, temporary fix) due to the bearings squeking. 9 bolts, and a couple of oil lines, am I correct? It takes them a day to due the Turbo, and finaly I get a call today but with bad news. They start my car an it runs with a 10 on the AFR... All they did was change the turbo... Now it is dumping gas in the chamber. We try to throttle out of it a little and it stumbles and fights the whole the way. Let off and it idles down to a 100-200 RPM's. Smoke is black, and rich. What could they have done, or what would cause this. Also, when they try and look at it with a scan tool through the OBD II port, it comes up giberish. I can log it with EVOScan, and looked at ECUFlash to see if the map had been messed up. The comparison ECUFlash does prior to loading stated all was fine, and the maps were identical.
Voltage on the front 02 sensor is at half a volt.04503 and goes down to .01. Thinking maybe the messed up the front 02 sinse it is part of the turbo dump housing. Any Ideas would be greatly appreciated.

Thanks in advance

 

Are you boosting the same as before the new turbo? or less boost?

 

Well what was your original turbo and what turbo did you just put on?

 

could have messed up a O2 sensor?

 

Bad 02 sensor or connection

- Bryan

 

when they replaced the o2 sensor the probably dropped it or damaged it. Does it run the same with the maf plugged in?

 

Sorry for the late reply's.

MAP for boost curve is identical. We havent even been able to go for a testdrive. The thing barely idles, and is idling with a 10 on the AFR. If you try to throttle a little, it floods itself out even more, and the engine RPM's dont increase. very weird. When you let off, the car almost dies.

I thought I stated it was the 2004 stock turbo with 9.8 hotside. New turbo is a 2005 8 MR turbo with 10.5 hotside, thought he hotside cast peice was cracked, so had to frankenstien it a little. Just swapped out the hotside from my stock turbo and put it on this used newer turbo.

I replaced the front 02 right at a year ago. I did use on of the universal 02 sensors.
This is what they are thinking on the 02, so we ordered one, but a true OEM is going to take a week to get here...lol.

We checked the MAF and don't think that is it. He checked it by taking out the Air Filter and puting his hand in front of it. Please indulge me a little more in how to check the MAF?

Thanks in advance.

 

Just checked back with the mechanic, new 02 installed, and it still runs rich.
He says his scan tool won't even read my ecu...???? why?

I have the ECU FLash Tephra V.6. Can anyone tell me why the scann tool wont read the ecu?

Any help please would be awsome.

 

boost leak. a big one.

edit... its rich at idle? maybe not a boost leak. boost leaks are lean at idle.

double edit, if a coupler is completely disconnected they usually barely run, spit black smoke out the back and you can't give it any gas without it for the most part stalling/dying. i would check for pipes anyway.

 

What couplers are we talking about?

 

+1 on the O2. Our cars do not respond to "universal" O2 sensors very well. Hit up your local Mitsu dealer and ask them for one they pulled out of another mitsu. I did this and they gave them to me for free. They have them when they swap engines...the drop in engines have new o2s already installed.

+1 Again on the couplers. If any of them are loose, especially near the MAF you will have issues. Your intake pipe must be tight too. Also make sure any plugs that are on the intake are capped and zip tied.

Check the connector to the MAF too.

 

Just got robbed in the shorts, $350+ for one, and yes, still rich, not as bad, but mechanic says it still wants to die.

Running the stock airbox with a K&N, hasn't been oiled for a while so know chance of that messing up the MAF (the oil that is).

Checked the connection to the MAF too. Plugged in tight. If the MAF got screwed up somehow would it cause this issue? How does one check the MAF? The honeycomb is solid or still intact...no clue what would be wrong with it or how to test it.

 

Have your mechanic do a boost leak test from the suction pipe (remove only the air box and MAF). Your car is exibiting nearly the same problem that happens when you blow an intercooler pipe.

 

check the following: lower intercooler pipe connection at the turbo and on the passenger side of the intercooler.

the upper intercooler pipe connection on the intercooler and intermediate connection behind the radiator fan, and last the connection at the throttle body.

all of these couplers must be tight, all the way on the pipes, and free of any tears, rips, holes.

 

I am assuming this is the section of hose that does the weird bend under the stock intake box. Kind of an L shape hose. THe radiator fan has apparently hit this hose and nicked it, small tear. He is sealing it to see if the issue gets better.

Question though, I know this would cause a boost leak, but would it cause this much of a richness problem? There is no boost at idle. Maybe I don't understand the full realm of the MAF and amount of air that the ECU senses at Idle, due to a nick or tear in the hose.

Enlighten me if you will please. I know it is a problem and have my stock hose for a replacement in the interem that I will be taking to him. Would this small tear cause that much of an issue?

Thanks again.