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Discussion Starter #1
just wondering because that's what I was shooting for.

hopefully I don't sound like an idiot. but if I do, I'm sorry. and I have already searched this site and others for my situation with no real answers. so I thought I'd ask here. right now it's bucking when I hit higher boost (since I don't have a boost gauge, lets say anything over 5-8lbs). car runs fine otherwise. drove it probably 50 miles when I first got it, and about 100 miles after the new parts. I'm thinking that the maf is freaking out and or motor is running lean.

here is some history: I bought this car to be a family wagon (98 1.8t tip) and didn't want anything crazy. after reading about the sludge problem and having an oil light on. I tried the auto-rx. got about 50 miles before I blew the turbo (not sure if it was related to the oil pump because it looked like a rock got into it)



anyways I did the oil pump, tb kit w/waterpump and thermostat, and k04-015 turbo from ebay along with a forge dv, new pcvs, vc gasket and new plugs ngk bkur6et. (a big THANK YOU to PW members for all the diy stuff) car fired right up and idled great. no leaks. awesome! take it on a test drive, everything seems to be working. I'm super happy with it, and decide to see how she boosts. WTF? the motor feels like it wants to jump out when the boost starts getting higher (or remember when you were learning to drive a stick? bucking back and forth. kinda like that) car will drive fine and hold some boost, as long as I don't push the pedal past 15% throttle. if I do, no matter what gear I'm in, it will buck then run fine after letting up. I can rev it in neutral fine, but not under load. and if I down shift it, it will run fine at higher rpms as long as I don't spool up the turbo too much.

now onto the question. can a stock aeb run a k04-015 turbo on stock software? I've heard of it (not sure if that was an aeb though), the damn ad on ebay said "bolt in, nothing extra needed". but the more I look into it, sounds like an aeb will run lean with the smaller injectors. but would that cause my bucking and jerking? or do I have other issues to address? do I have to get a chip and injectors for it to run right? how about a 5bar fpr? I've read about an mbc. but never got my answer on that thread. I really just wanted a stock running car to haul my daughter around in. I already have my fun car. I know it's a honda. but it's a turbo'd rt4wd. heres some pics of it.



I did get the codes cleared. had a few, can't remeber them all. but one was the maf getting too high a reading, and another was misfire in cyl 4. those ones caught my eye. I didn't even think to write them down. (I know I'm a dumbass) I will next time for sure.

thanks in advance and sorry about the long post. hoping someone can help or if this has happened before to someone else.
 

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Superbad
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1) Get a Boost Gauge (very important)
2) Yes you can run K04 on "STOCK ECU" has to be AEB w/ ECU Ending in 557P and stock injectors.
3) To fully take advantage of the K04, i would match Proper Hardware with Appropriate Software.
4) Post your location, so someone with a VAGCOM close by can help or scan your car. ( *edit just saw Portland, OR)
5) Go to autozone or use a generic OBDII scanner, post your codes about the MAF and the misfire.
6) If misfire, blinking CEL, check your plugs (make sure correct type and correct gap), also could be your ICM (how many miles?), also could be your Coilpacks (have you tried musical coilpacks yet?)
7) You need to do a TBA (throttle body adaptation via VAGCOM) if your idle is bouncing or not stable.

Please report back after checking a few items on what i listed above.
 

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Discussion Starter #3
1) Get a Boost Gauge (very important)

on it's way. been looking around for an old autometer I had. friend is bringing one over tomorrow.


2) Yes you can run K04 on "STOCK ECU" has to be AEB w/ ECU Ending in 557P and stock injectors.

awesome. it does end in 557p. do I need anything else to do that? I do understand that I will have to sort out my problems that I have now. but glad to hear that it's possible.


3) To fully take advantage of the K04, i would match Proper Hardware with Appropriate Software.

maybe down the road. thought about chip, trans chip, injectors, and cat delete and exhaust. but for now, would like a stock like car. car did come with a k&n drop in. so for now would be the k04, k&n, and forge dv hopefully on the stock software. along with anything else that is necessary.


4) Post your location, so someone with a VAGCOM close by can help or scan your car. ( *edit just saw Portland, OR)

no worries, going on thursday or friday to visit the vagcom. still no cel right now since being cleared. haven't driven the car since yesterday. still have the airbag light on though.


5) Go to autozone or use a generic OBDII scanner, post your codes about the MAF and the misfire.

shouldn't need this since the vagcom. right?


6) If misfire, blinking CEL, check your plugs (make sure correct type and correct gap), also could be your ICM (how many miles?), also could be your Coilpacks (have you tried musical coilpacks yet?)

not blinking. at least not yet. I did replace the plugs with ngk bkur6et plugs (i will double check them though) I read about plugs and everybody has their own opinion about them. I was going to get the ngk pfr6q plugs but got what was already in the car instead. there was a big price difference also that made me choose what I got. I'm always willing to hear others opinions also.

car has 138k the icm looks newer but not sure if it's the original. it is a hugo.

thought about the musical coil packs, but haven't done it yet. sounds dumb I know, but I couldn't figure out the plug on them when I changed the plugs. I also didn't want to hurt the wiring. so I was going to do that when I figured it out. or if someone can tell me.


7) You need to do a TBA (throttle body adaptation via VAGCOM) if your idle is bouncing or not stable.

idles great. no problems there. but will ask about the TBA when it gets scanned again.



and thanks vwblackb5 for your help
 

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Discussion Starter #4
I know I have to sort out my issues with this car first. but if everything worked the way it should, what is needed to run the k04 on the stock ecu and injectors? fpr, maf, mbc? or all of the above?
 

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I know I have to sort out my issues with this car first. but if everything worked the way it should, what is needed to run the k04 on the stock ecu and injectors? fpr, maf, mbc? or all of the above?
You shouldn't need anything to run the k04-015 on the stock ecu. You just won't get the full amount of power out that the turbo is capable of, but if there is nothing wrong with the car other than the k03 going out, then you can bolt on the k04 and it should be fine.
 

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Discussion Starter #7
I have to say that is one cool Honda! Never seen anything like it before.
thanks, it's a really fun car. it's an 1988 civic wagon rt4wd



You shouldn't need anything to run the k04-015 on the stock ecu. You just won't get the full amount of power out that the turbo is capable of, but if there is nothing wrong with the car other than the k03 going out, then you can bolt on the k04 and it should be fine.
so nothing else is needed? other than fixing my issues that I have now. I did just take the car out to the store. seems to be running fine, no cel. probably going to take it out on the freeway later to see if that holds true.


and a big THANKS to you guys for the help.:thumbup:
 

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I wonder if the N75 is functioning properly or if the waste gate adjustment on the Chinese turbo isn't set right?

Sounds like as soon as it gets under load and starts to boost, things go crazy. Perhaps a boost control issue? Perhaps over-boosting? I know the AEB has no charge pressure sensor, but it still has a MAF and if too much air is being sucked in, the ECM will know about it and take action. Post up the boost you're seeing on the gauge when you get it installed.
 

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What happened to the nut that lives on the end of the turbo shaft?
I bet it, and the shredded compressor blades are lining the inside of your oily charge pipes and intercooler. You may want to remove those parts for inspection and a good flush. Those debris will work their way through the intake and into the cylinders eventually.


 

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Discussion Starter #10
just took it out and still has the herk and jerk under load. I can ease the wagon to 70 on the freeway. just not with a higher boost (I know, I'm getting a gauge tomorrow) I did try to push it, but heard some pinging getting onto the freeway when it was still somewhat cold and holding some boost. after that I just drove it normal. car did do awesome around town where the speed limit is 25 or 35. and on a good note, this thing spools up nice and quick. for a knock off, seems ok so far. still no cel either. I'm hoping the vagcom see's something. figuring it's like you said steve, overboost freaking the maf (how would I know if its the n75 or wastegate actuator?)or lack of fuel would be my other guess. could be both. or one causing the other. hoping to see something with the boost gauge tomorrow.

yeah that nut did some work for sure. you should see the rest of it. the shaft sheared in half between the housing and making it all go wobble wobble. now it's just a paper weight. I wonder where that nut went? only time will tell. maybe an excuse later for a cat delete. wait I don't even remember seeing it when I replaced the turbo. so who knows. anyways I'll get some pics of the turbo later.

I'm wondering about some stuff I read in other threads about a 5bar fpr, theres another thread about using a mbc? I wonder if either one would help. some input here would be cool.

I'm already thinking of replacing some of the maintenance stuff like the coils and the icm. since I've gotten this far, I figure start somewhat fresh to prevent any more issues later. (I did clean the pipe and tubes, but not the intercooler. duh on my part there) I've gotten to drive this thing like 200 miles so far. and all of them have had issues. it is getting better though and I'm still being optimistic about this wagon. I still have the trans stuff and suspension planned too. and also, now it sounds like a front wheel bearing. :banghead: is there a diy on those? maybe an alignment too. hopefully this wagon ends up good as new when I'm done. it's almost costing like one.:crazy:

anyways I'll complain to myself now.

thanks for all your help

I will post boost readings and if I get to a vagcom, those results also. that may have to wait till friday though.

thanks again
 

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If you are indeed over-boosting, you can try adding a Manual Boost Controller to see if that helps. You would want to hook it up in Parallel with the N75 valve. This way the ECM still has control of boost production (via N75) but the MBC will function as an upper limit.

A faster reacting N75 may also work. There are several versions of the N75. Some react slower (the N75 Race version) and others react faster. I don't know which versions react at what speed.

This is the theory behind how N75 reaction speed effects boost production...

The turbo waste gate is normally closed so all exhaust gasses are directed through the turbine. When you throttle up under load and exhaust flow increases, the turbo spools up enough to produce boost on the compressor side. The ECM monitors intake airflow (MAF) and on some engines, boost (Charge Pressure Sensor). When the proper amount of airflow/boost is being produced, the ECM starts sending electric pulses to the N75. The N75 is a solenoid that meters the amount of boost being sent to the waste gate actuator. Sending boost to the actuator opens the gate and allows some exhaust gasses to bypass the turbine. Less exhaust pressure on the turbine (less energy acting to spin it up) translates to less boost production.

A slower reacting N75 will get you higher boost, or an initial boost spike because the limiting action of the gate system is delayed. If it's too slow (or not working at all) you'll over boost or boost-spike and the ECM will see this and take action to correct this.

boost...
over-boost...
Warning Will Robinson, we are over-boosting and must take action!...
ECM cuts boost production via N75 and if that isn't enough I think it may also cut fuel...
boost drops back below requested boost...
ECM calls for boost again by allowing the waste gate to close...
The whole process starts over and repeats itself (surging) because the boost control system can't react quickly enough to accurately control boost production in real-time.

Another way to think of it is to image a lawn mower engine with a slow reacting RPM governor. You go open-throttle and revs overshoot due to the slow reacting governor. By the time the governor finally responds, rev's are WAY too high and governor makes a drastic throttle correction. Now the throttle is almost closed and RPM's drop. Slow reacting governor allows RPM's to drop WAY too low before it responds and governor again makes a drastic throttle correction. Back and forth between way too much and way too little, all because the control system doesn't react fast enough.

The spring in the gate actuator and the adjustment of the gate actuator rod are also part of the boost control system. If they are not properly tuned to the system, you can get erratic boost control.
 

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I have the same issue with my 98 passat 1.8t sedan. I do have a gauge and if your car is the same as mine you are hitting 13 psi and your ecu is hitting fuel cut. The car feels like it hits a brick wall for a split second. But the bucking thing is a misfire. Make sure you have the right plugs in which are bosch fr7ldc for aeb engines. Vw's are very finnicky about which plugs you are running
 

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My queston is are there any ways to get around the fuelcut anykind of diode mod or anything? I'm and electronic engineer tech so if I know exactly what sends the signal to the ecu to cut the fuel I can figure a way to tweek the signal. And I don't have a map sensor I have a maf
 

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if I know exactly what sends the signal to the ecu to cut the fuel I can figure a way to tweek the signal. And I don't have a map sensor I have a maf
Both your AEB and the newer systems are MAF based. The newer ones also have a boost sensor (not a MAP) in addition to the MAF. The ECM itself decides when to cut boost and fuel. It will make the determination based on MAF data, rpm, throttle position. I don't know of a way to modify those signals to get what you're looking for. The usual way to go about it is to modify the software.

I think it was Rusty that modified a MAF by drilling holes in it to change the way the flow was measured. I forget exactly what he was trying to achieve and if it worked or not. He was home-tuning an AEB without modifying the software. Maybe do some searches for his posts.

How are you hitting 13 psi? Manual Boost Controller? If so, you better watch out for running lean on the top end.
 

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Discussion Starter #15
I have the same issue with my 98 passat 1.8t sedan. I do have a gauge and if your car is the same as mine you are hitting 13 psi and your ecu is hitting fuel cut. The car feels like it hits a brick wall for a split second. But the bucking thing is a misfire. Make sure you have the right plugs in which are bosch fr7ldc for aeb engines. Vw's are very finnicky about which plugs you are running
I actually didn't get a gauge locally and ended up ordering one from ecs along with my control arms. but will definately keep 13 on my mind when the parts get here. steve, you make it sound like that's high. where should it be?

plug wise I went with ngk bkur6et plugs cause they were cheaper and what was originally in the car. did your car buck with the bosch plugs? or did that stop after putting them in? I'll have to look into them

so far just from searching, I have found threads on a 5 bar fpr being a fix, a mbc like steve said, and the obvious chip and injectors with a 3bar fpr along with other supporting mods, and also going with a bigger maf, possibly one from a vr6 car. but not sure on the fit. have to find out about what rusty did. all of them sound like they would work in theory. I would just hate to end up spending more on trying to keep it stock, when I could've just gone with the chip and other stuff.

I did order a 5bar fpr hoping it would at least compensate for the smaller injectors. thinking about a mbc also. but right now the plan is to figure out the bucking action. figure if the stock setup is suppose to work with a k04, my problems are within something else. like the plugs, coils, icm, n75 and or whatever else. question about the icm, if there is no cel on, the icm should be ok. right? I'm getting new coils just to eliminate them from the scenario. would the meyle brand be ok? since I ordered the fpr, I'll put that in to see if does anything. along with checking the plugs. figure I won't see a boost gauge till this time next week. maybe try and get a cel up to go get scanned.

here's another question that may sound dumb, are there codes even without a cel on?

forgot about the wastegate actuator. can I calibrate that somehow?


thanks again for the help guys. sorry for the questions too. but... if I don't ask, I'd end up figuring it out the hard way.:cry:
 

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OK, couple things, like Steve said, your wastegate may be set improperly leading to boost spikes. From what I read, you don't have a boost gauge right? Get one now! If you don't have a VAG-COM scanner, get one now.

Second, before you even think of trying to bypass fuel cuts and throwing on adjustable fuel pressure regulators, you need to get a wideband gauge installed. Innovate motorsports has a very well priced one at $229 for the whole package including gauge.

The AEB engine has very primitive failsafes compared to the later engines. It's narrowband O2 sensor only works during cruise and idle. Once you go into boost it just goes to the load/MAF tables and selects it's injector duty cycle from there. It can run as lean as can be and the only thing that will save you is if the knock sensors go crazy it may cut the fueling. Also, if the MAF readings are way out of whack for the RPM/load it may cut fueling as well.

At this point, you're trying to throw way too many variables into the mix without any way of measuring the outcomes. If you're going to play around with an AEB you need some way of measuring what you're doing.

Finally, regarding plugs, I find that the cheap copper plugs gapped at around .28 work well.
 

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13 psi is high for a stock AEB. It should be somewhere in the 6~9 range depending on other variables. That's why I asked him how he was boosting to 13. He may have a chip or a MBC, I don't know.

A bigger MAF is only needed if you're exceeding the capacity of the stock MAF to measure airflow. I don't see this happening on a Ko4 with stock programming.

Bumping up fuel pressure with a 5 bar regulator will do this...

More fuel injected per injector cycle.
O2 sensor reports rich condition.
ECM dials fuel trims leaner to get A/F ratio back where it belongs.
You're back where you started minus the money spent on the new regulator.

In closed-loop operation, the ECM will learn to lean out fuel trims. If trims go too far out of bounds, you'll get a CEL.

When you go Wide Open Throttle your AEB goes open-loop. It will apply the same lean trim numbers to your fueling but now it won't have any O2 feedback. Now you've got a K04 (or a K03 & MBC) pushing more air than the system is set up for and leaner fueling. When you go lean in the higher RPM's, the ECM won't know it. The AEB doen't have a boost sensor so that safety-net is non existent. Your only saving grace is when the ECM sees MAF numbers that are higher than expected and cuts boost, fuel or both.

I know a few people have re-engineered the system to get more performance on stock programming. In every case I've read about these were people that really understood the system thoroughly and did a lot of data logging as they modified things. Unless you're up to that task, and don't mind risking the engine, why not just get the proper software?
 

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Yes I have a mbc and an a/f gauge and I can run 12 psi all day and the a/f stays in rich but as soon as I let off it just bounces from stoich to rich. And I'm probably going to run with revo software and be done with it. My car has never seen lean. I don't even know what the red leds look like. Tell me if I'm wrong
 

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As long as you're monitoring it properly (sounds like you are) and staying in a safe area, it shouldn't hurt anything. What too many noobs do is pop in a MBC because they are cheep and start dialing things up with no way to monitor the results. If some boost is good, more boost is better, right? Soon enough the need for power has them dialed up to a setting that hurts the engine.

Look up the Revo website and see if they have a dealer listing.
 
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