coolguycooz

Ok my friend asked me to check out his evo because he said he was only boosting .7, so the first thing i figure is ok .7 bar is 11 psi must have something to do with his lines. ( no restrictor pills), well sure enough they were messed up ( person before him ran a MBC on the car most likley), so he decided to order a MBC.

also i decided to log his car, his TPS sensor never went up to 100%, it started at like 60 and slowly climbed up as the rpms went up,

Also another question is, he was getting ridiculous amounts of knock, his rom was not messed with all stock timing and fuel,

so what i want to know what was up with the knock? i couldnt be because he was only boosting 11 psi, or the fact that his TPS was messed up?

also with the foot off the pedal the tps read 13.3 exactly where it should,

Ill post the log when i get my lap top out of the car.

MalibuJack

iTrader: (5)

With the MUT loggers, I think 13% is about right, it should associate with .7volts measured with a voltmeter at the sensor.

How are you measuring boost BTW?

coolguycooz

with a boost gauge, its only getting up tp .7 bar plus the highest load calculated was like 174,

now i know load isnt correlated directly with boost, but higher loads have an indirect relation with boost,

so i know it has to be the lines from the compressor housing wastegate actuator and BCS

now that thing that bugs me is i was able to feel no restriction pill in the line to the BCS, and it is hooked up, i reaad that staright line no restriction is 11 psi, But the bleed off was still hooked up so i figured it should go past 11 psi,

also why was it knocking so bad, it cant have something to do with the TPS signal, and fuel delivery can it?

MalibuJack

iTrader: (5)

Initially It sounded like the solenoid isn't working, however with all that knock your complaining, the ECU could be protecting itself and not allowing the car to boost over wastegate pressure. However look at my additional information below..

A few things to check..

The restrictors in the lines, if their missing or hooked up backwards, you will only see 11psi or so.. Its likely the restrictor is on the side that goes to the actuator and not the boost source, this is the most common error in reinstalling the lines after they have been removed for whatever reason, and this is the typical cause for having wastegate pressure no matter what.

The DV could be blowing open, I've seen this happen when the line was pinched or the diaphragm was damaged, Generally there are other symptoms other than that though. The vacuum source could be disconnected or the line has a leak or cut.

A torn/cocked/loose intercooler coupler or pipe, this one is tougher to find as its sometimes not obvious when it came loose.

Now the knocking.. Its essential to get a wideband on the car, the knocking is likely due to a lean condition, and a lean condition is likely due to one of the above problems, that is, Unmetered air bypassing the MAF..

Also check all the vacuum lines for cuts or leaks..

My guess is the car was tampered with, and put back together and never tested to make sure everything worked right, or something came off (a vacuum line) or any number of things.

Is this a new car for him, that he purchased used? Had he been driving with the car for some time before he had a problem? This is the type of information you need to find out.

coolguycooz

ok, its not the BOV because i put mine on his car, it didnt fix it, its none of the piping couplers because i examined them all,

this is what i found to be weird, he told me when he first got the car, he would boost to 1.3, so i asked him if he messed with the lines. or if anybody else messed with them sense then. he said "No".

so thats whats bugging me, now when you say unmetered air passing the mass air flow sensor, he does have one of those mushroom style intake filters on.

i'm going to pull that and make sure it still has the honey comb, and throw my stock air box in just to test it and see if the knock goes away.

ok so boost and knock, im assuming are solved.

Now what about the TPS? MJ i remember you saying it was adjustable or something? but i dont see how. also the weird thing is its not cutting out or anything, it just seems as if it takes forever to get to 100 %, like if you go WOT at 2k rpms in 3rd it will slowly start coing up from 50 to 100%, and it wont hit 100% until like 5500 rpms.

MalibuJack

iTrader: (5)

The adjustment for the TPS sensor is a few screws holding it onto the throttlebody. Since the idle % is about 13%, and the TPS value is rising slowly, then I would suggest maybe replacing the TPS sensor or checking the wiring to it..

Monster knock and other things can actually occur when the TPS sensor is reading low and the actual throttle position is higher (its similar to getting unmetered air)

For TPS to slowly rise, I have never really seen that before, I would take a look at the throttle plate and see when he hits the pedal if the plate opens and closes quickly.

I have only heard of two people with bad TPS sensors of all the cars I've ever looked at, but if you can't find anything else, then at least have that tested or replaced.

coolguycooz

Thanks MJ, ya thats what i figured too, if the TPS signal is low while the throttle plate is actually fully open. Thats most likley whats causing the knock.

ill probably tell him go buy a new tps sensor from the dealer, then get his boost fixed after that.

evil mechanic

iTrader: (11)

let us know if the new sensor fixes it.

coolguycooz

ok this is weird as hell

The UNOS MBC came in, i hooked it up for him, right off the bat with it fully turned to the left, least possible bleed off in the MBC, the car hit exactly 1.4,

so i went to log and this is what shocked me,

his TPS signal was 100% all the way through after hitting the pedal ( all i did earlier was examine the wires to the tps, might have slightly wiggled them).

And the thing that bugs me the most is , 0-3 counts of knock vs the 10-12 he was getting at 11 psi, and thrown off TPS signal.

Now to figure out why, either the thrown off TPS signal was causing knock do to a partial control of fuel delivery? (im assuming TPS regulats like 10% of the fuel delivery?), or because the car was underboosting it was getting knock.

if thats even the case what fixed the TPS? i doubt me wiggling the wires slightly did anything, they looked clean, the casing still on them,

either way, we did pulls for an hour straight tps was perfect, boost was perfect knock never past 3 counts, and all i did was hook up a MBC up to the car.