Boost Leak and now Horrible Idle

[SoonToBeDSM06]

ok i got this tsi about 2 weeks ago and been fixin stuff ever since.. i kno i kno i bought a DSM... But i was going through a whole tank of gas in like 100 miles which i know was horrible. i started to wonder what could be causing this. the car came with a SAFC and i set the tables to zero. I then put it on Karman and it runs like shit when i do. The car like bogs out when i accelerate and goes nowhere when i am cruising. So i put it on Hot-wire so i can at least drive it. I can smell gas everytime i start the car, at a light, and when i stop it. I then look at the inaccurate A/F gauge that the guy hooked up to the ecu and it read lean all the time. so i start the car one morning and splice the 02 sensor wire with the voltmeter. read .25 the whole time and no matter what little adjustments i made on the safc it still read that. Well i went to autozone b/c they used to help me on my Z24. The guy was wondering how i could use this 6 bolt with my 95 ecu . And we both found the problem at the same time. The guy that had it before me put a dejon upper and lower IC pipes in and left the intake pipe a complete mess. There were like 3 little flex pipes cooupled together and they both came loose. So i had shit loads of unmetered and unfiltered air coming in, screwing up the maf signal, throwing about 4 codes and sucking down a lot of gas. So i fixed it and i also fixed the leak that was coming from the MBC. i start the car up and it runs better. it idles at like 1000 rpms though and doesn't go down. I rev it and it goes up and as it comes down it goes ALL the way down to zero on the tach. The lights dim, radio shuts off and engine dies for like .1 seconds and then it comes back up to 1K again. Well it only does this when the SAFC is set on Karman. It never drops under 1K on any of the other sensor types. I took it out for a drive and it does the same thing when i push in the clutch and press the brakes to turn. And then it bogs a little when i drive it. I'm starting to think the SAFC is either screwed up or the idle motor is bad b/c i had a code for that. Please help b/c of these rising gas prices and 7 mpg it doesn't help me.

 

[SoonToBeDSM06]

after reading the vfaq for idle surge i have a symptom of it. the car almost stalling out when i hit the clutch and brake. so do u guys think i'm right or is there more to it?

 

[ddavisaf]

I would start with the codes. If your ISC is throwing a code you should replace it. Check your plugs and wires. Do a compression test. Sounds like your o2 might be acting up as well. What codes were coming up?

 

[SoonToBeDSM06]

idle speed control malfunction, EVAP Code but when the guy installed the 6 bolt he took off the emissions stuff, MAF malfuntion

there was more before i fixed the leak but they haven't came back yet.

 

[ddavisaf]

A boost leak will cause a MAF malfunction. Replace your ISC. I would take a look at your o2 also and see if that's bad. Unfortunatly I don't know to much about the SAFC's so I can't help you there. But I know hundreds of people have had similar problems concerning them, so just do a search for help with that.

To recap for both our benifits:

You found and fixed all the boost leaks in the car.
Car idles around 1k and tries to die with clutch and brakes engaged.
You're throwing a CEL for your ISC, MAF, and Evap?

correct? Am I leaving anything out?

 

[mramc3]

I had the same problem. I tested the resitance across the ICS motor and it tested fine. But there was an internal mechcanical malfunction inside that eventually led me to replace the ICS. I was able to clean the throttle body and check the BISS screw to see if it lost the rubber O ring. Everything ran smoothly after that.

 

[SoonToBeDSM06]

I had the same problem. I tested the resitance across the ICS motor and it tested fine. But there was an internal mechcanical malfunction inside that eventually led me to replace the ICS. I was able to clean the throttle body and check the BISS screw to see if it lost the rubber O ring. Everything ran smoothly after that.

thanks for the input u guys. and yes that is correct i'm not leaving anything out.

 

[SoonToBeDSM06]

OK so i have been driving it for a couple days and nothing has been right ever since...... since the engine only bogs down when on the Karman setting on the AFC i put it on hotwire so i can drive it. Welll......... one of my belts is squealing bad and i tightened the power steering pulley up and it still squeals. And tonight when i pulled out of my driveway.. the low beams just shut off and i had to drive across town with the highs on and ppl didn't like that very much. I will check a fuse tomm. I had to take my grl home and when i shifted to 4th i heard like a little rumbling sound coming from either under the hood or the dash was raddling. So i shifted back to 3rd. And when i got there i popped the hood and the manifold was glowing red but i wasn't really on the boost. Well i let it cool off and then i put the AFC settings back on Karman and whenever i'm at a stoplight... the car keeps stalling when i push in the clutch and press the brakes and the rpm needle just bounces up and down between 300 and 1500 a couple times. And my wastegate seems to open up when i'm on Karman also b/c i pulled trhe screw out b/c i was getting 20 psi on a long run a couple nights ago and i believe it still has stock pump and injectors. It seems like it doesn't want to run right and i can see the gas gauge drop as i cruise down the street. Any more ideas from you guys?

 

[mramc3]

Sqeaking belt - Why did you choose the power steering belt? Does it just squeak when you turn? On a cold startup? I am thinking your alternator belt. More info on that please.

Bogging. Did you take care of the ISC yet? Basically it seems like you are avoiding the problems and hand and just trying to trick your ecu so that your car is drivable. Seriously, replace the ISC motor. This greatly effects your idle. Especially when you step on the clutch.

 

[oldman]

Questions for the thread starter. I suspect the injectors are stock 450cc, what is the purpose of the afc? Did he hack the mas? Did you perform a real leak test or just fixed whatever you can see?

 

[toojung2die]

FWIW - Last week I attacked a bunch of small boost leaks around the intake. With a spray bottle of soapy water I found little leaks at the lower injector seals, t-body gaskets, t-body shaft, BISS screw, and many vacuum hose fittings. After eliminating all the leaks I learned that a little leak + little leak + little leak = Big Leak. When I finished and started my engine the idle was almost 2000 rpm after warm up. The proper way to set the idle rpm on a 2g involves using the MUT-II diagnostic tool. Not having one I counted the number of turns the BISS screw was at (2 turns out). I slowly turned the screw in and the idle rpm dropped. I left it at 3/4 turns out. The idea is to get the BISS screw set so the ISC is in the center of it's travel when the idle speed is correct so the ISC has the maximum range available to adjust the idle rpm. Without a MUT-II I have no way of knowing if my adjustment is optimum but for a week now my idle has never been steadier. It's obvious my BISS screw had been adjusted in the past to compensate for the intake leaks.

 

[SoonToBeDSM06]

mramc3- the squeaking belt was the alternator belt... the ribs were about gone so i'm putting a new one on tonight. I tested the coils on the ISC and they all read 30 ohms and i still need to get a 6 volt battery to test the motor itself.

OLDMAN- The AFC was on the car when i bought it. I think they are stock injectors b/c they have the blue tops to them. And all the honeycombs are still in the MAF. I have to pay for insurance and registration at the same time so a little low on money but i will get pick up some parts to make a boost leak tester. I just sprayed all of the couplings with soapy water and nothing so i dunno. The guy also took the evap crap off and today i found the egr nipples open and unplugged. Will that cause the high idle? Plus the sensors that were on the 7 bolt were just left laying around in the engine like the Map sensor is just laying beside the elbow pipe. OH!!! I FORGOT. The o2 voltage is stoich when i start the car but it falls and stays at .2 volts in idle, WOT, and crusing speeds. It just stays there. There is also fuel laying in the bottom of my muffler. I was cleaning the throttle body today and the ISC motor and they were black. The new spark plugs that have like under 10K on them were also carbon fouled. I couldn't even see the tip of the plug.

toojung2die- I know i have a 2g but it has a 6 bolt motor in it so do i still need a MUT-II diagnostic tool?

The engine only does this when the SAFC is set on Karman for the sensor type. Any other choice it just idles high but it doesn't bog out.

 

[oldman]

It could be anything at this point, just too much uncertainties. I suggest going back to the basics.

1. If you're sure the injectors are 450s and the maf is un-hacked, physically remove the safc out of the car instead of just zeroing it out. When troubleshooting, it's best to keep the system as simple as possible. Again I stress, make sure they're 450s.

2. Soapy water during idling can only possibly (not very effective) detect vacuum leaks between TB and head but not boost leaks because there are no pressure air to leak during idle. Perform that long overdue pressure test.

3. Perform dry and wet compression test. since the car is new to you, let's make sure everything is covered.

edit: BTW are you venting the BOV?

 

[SoonToBeDSM06]

no i'm not venting the blow off valve. Plus it seems like my wategate isn't working either b/c i can only stay under 4K or else boost will rise higher than i want (20 psi+) I have the MBC screw backed out all the wayi can and it still won't open. Its a little rusty down there and the wategate actuator looks a little rusty too. Maybe some PB Blaster?

EDIT: I tested the ISC today and tried to power the coils with 6 volts like it says on the site and it doesn't do anything so its bad.

 

[oldman]

no i'm not venting the blow off valve. Plus it seems like my wategate isn't working either b/c i can only stay under 4K or else boost will rise higher than i want (20 psi+) I have the MBC screw backed out all the wayi can and it still won't open.

You have boost creep, rare with T25 but still possible. You have a very complicated issue here, possibly multiple problems everlapping. Take my suggestions seriously and start from the basics, it's time for spring cleaning. In the mean time, keep all WOT to only during test runs until you figure out this mess.

I tested the ISC today and tried to power the coils with 6 volts like it says on the site and it doesn't do anything so its bad

The motor should turn if done properly, double check your procedure.

 

[SoonToBeDSM06]

well the funny thing is that the idle is only like this when i have it on the correct setting on the SAFC. So i'm thinking wired it wrong. And i have a 14b. Could it be i have a bad MBC? I never heard of boost creep on a stock car. And the car sucks down gas like crazy but it also could be the gas gauge since i have a 2g AWD i heard those were reading wrong

 

[toojung2die]

toojung2die- I know i have a 2g but it has a 6 bolt motor in it so do i still need a MUT-II diagnostic tool?

Since I don't know what the differences with a six-bolt swap involve for certain I won't speculate. The MUT-II is the Mitsubishi diagnostic scan tool used by dealers. Very expensive and not available unless you pay the dealer or have juice with a Mitsubishi technician.

 

[boostedgst2984]

OK dude ill be your Saviour. I just went threw the same exact problems as u with my 6bolt. And i couldn't figure it out for the life of me and my friend. Your idle is surging and dropping because their is a vacuum leak and when it hits a certain rpm it seals the leak and drops back down. And does this over and over and over. I made a boost leak tester and found out my injector insulators were bad and the intake manifold gasket had 2 big holes in it. That fixed my problem. I would take out the safc first if you have stock injectors. You dint need the map sensor or the crank sensor either.

Do you have a CAS on your cams. If so i would double check to make sure that is wired up correctly. And make sure it is not 180 off time. But check the wiring of the cas first and leave changing the sensor to 180 degrees as last resort after checking everything else.

Also check to see if he has rewired the ecu by changing the injector firing order. Or check the spark plug order on your coil. Because u have to compinsate with the 6bolt and the 2gn ecu. You have to change the firing order.

Get back to me on that stuff

 

[SoonToBeDSM06]

Will a blown headgasket create some of these problems? We were testing it today and there is white smoke comming from the exhaust. I have a clear tube for the coolant from the cap to the tank and it had some foam in it. There is a little part of the HG showing on the side and it looks oil soaked. There is oil laying on top of the oil filter housing. And when i bought it the guy said there was low compression on 2 of the cylinders ( like 110psi) and a mechanic did the test. I still need to find a compression gauge i can use b/c i'm dead broke now so i can check it. I have an ajusa head gasket b/c it came with the car and the spare 6 bolt. Would this conclude this prob?

 

[SoonToBeDSM06]

i did a compression test and here is what i got

Dry: 90-90-110-110

Wet: 110-115-120-120

so my rings are shot

 

[oldman]

i did a compression test and here is what i got

Dry: 90-90-110-110

Wet: 110-115-120-120

so my rings are shot

Hard to say. Assuming the compression test was done correctly, car fully warmed up and full throttle applied, I suggest double checking the tester by using another one. If the compression numbers stand, only a leakdown can tell for sure what is causing the low compression numbers. You should have done a compression test before you pay the guy, maybe you can call him and demand for some kind of compensation, I think he probably knowingly sold you a lemon. Besides the compression issue, you still have possible turbo, boost leaks and possibly crank pulley issue since the ps belt is squealing even after you tighten it. The only thing you can do now is to take them one at a time.

 

[SoonToBeDSM06]

i did a wet test and the numbers were 110-110-115-115 so i think the rings are gone and i do have another block i can put in that has 20K miles on it. The PS pulley was wrong and the alternator belt ribs were almost all gone so that problem is fixed. The bogging was from the plugs being carbon fouled again which i can go through a set of plugs in 3 days. Its running really rich and its fouling out the plugs. I have a guy that has a boost leak tester and will do that soon. I do hear a hissing sound at the throttle body at idle and i believe its the gasket b/c its pretty loud. I do also get 3 codes that always come back no matter how many times i reset the ECU. 1. Random Misfire (need DSMLink) 2. Emission stuff (totally erased from system except the EGR valve) 3. Idle Speed Controll Malfunction (Cleaned the TB and sensor and checked for resistance 28 ohms ) so i need a new ISC motor. Gonna get a rebuilt one. Anything else i could be missing?

 

[booosting92tsi]

Your idle is surging and dropping because their is a vacuum leak and when it hits a certain rpm it seals the leak and drops back down. And does this over and over and over. I made a boost leak tester and found out my injector insulators were bad and the intake manifold gasket had 2 big holes in it. That fixed my problem.

I had some idle surge as well, and i heard a big whossssshhhhhhh in the highway the other day. I did a leak test, and there's air leaking big time from under the INtake Manifold? Could the IM Gasket have blown? how did u get to big holes in the IM gasket??? How hard is to replace that?

 

[SoonToBeDSM06]

ok i talked to the guy that i bought the car from and he said that the guy that had the car before me had a nice tuned 16g setup. But when he sold the car to him the guy took most of the stuff out. He doesn't know what he left in it but thats why the S-AFC was included with the car because there was something. The injectors are blue on the top so i imagine they are stock. And since i zeroed the tables out it runs super rich and is fouling out my plugs and killed my 02 sensor i believed. The only way i can find out what he has is to take the pump out and see what kind it is. Is there markings on the side of the fuel pump that tells if its a walbro 255 or something like that? Plus i guess i need a logger now that i have fuel upgrades i suppose. I made a boost leak tester almost just need to tap a hole into the PVC end cap for the valve. Should i seal it with RTV? thankx

 

[booosting92tsi]

ok i talked to the guy that i bought the car from and he said that the guy that had the car before me had a nice tuned 16g setup. But when he sold the car to him the guy took most of the stuff out. He doesn't know what he left in it but thats why the S-AFC was included with the car because there was something. The injectors are blue on the top so i imagine they are stock. And since i zeroed the tables out it runs super rich and is fouling out my plugs and killed my 02 sensor i believed. The only way i can find out what he has is to take the pump out and see what kind it is. Is there markings on the side of the fuel pump that tells if its a walbro 255 or something like that? Plus i guess i need a logger now that i have fuel upgrades i suppose. I made a boost leak tester almost just need to tap a hole into the PVC end cap for the valve. Should i seal it with RTV? thankx

RTV is your best friend, if the last owner would have put RTV sealant in the IM gasket, i wouldn't have had the major leak that i have now, but nooooooooooooo!!!!!!!!! he had to be effin' lazy and save time.......it takes an extra minute to apply RTV........ do it......... it can only help!!!!!!!!!