ABY help?

[kenkawtf]

Well, I posted before and still have problems.

This cars spec;
Chipped
Garret T04E
Bosch 465cc injectors
Extractor exhaust manifold
3" DP
1,5bar WG spring
1,8t coils
Bigger ic

I bought this car after it had a fire in the cable harnesses. Most of the cables was connected to the MAF connectore, the rest im not sure of. Cut them and fuse everything together. Changes the hoses for the canister and cleaned everything up. Started the car and everything was fine except it was running fat and couldn't do more than 3/4 throttle. Maybe in limpmode? I found that the MAF also was burned - probably due the fire. Changed the MAF and it give me the right voltage. 1,5v with egnition on and around 2,5v when the car is idleing. Ride when I give it more throttle.

Still the car is running very rich, but when I disconnect some vacuumhose in the back in inlet manifold the car is running better. Put back the hose and the car runs ok, but still a bit rich. Disconnect the O2 sensor don't do anything at all.

Have pressuretest the susyem twice and can't find any leaks.

Can someone give me some hints please, this make my hair goes grey

[macspring]

One of the members on here or other I5 forums who lives near you and who has the ability to read the fault codes may be a good option to help you make progress. You'd need to check the test voltages on the lambda probe and the various other items to establish if they or their respective section of the wiring loom is 'intact' and working.

Going through it methodically is the best way forward but the least easy especially when it turns out to be the last thing you check.

Hopefully, others can post some more informative replies.

Check the 'engine map' on quattroworld - it covers all the individual items in detail and allows you to drill down on each 'device'.



Thanks from all of us to Dave and Greg for this invaluable facility.



As a matter of interest, has anyone checked the availability of an ABY engine loom from Audi Tradition notwithstanding the likelihood of the prohibitive cost and their credit card payment 'difficulty' that's been going on for months and months.

Best wishes.

[kenkawtf]

One of the members on here or other I5 forums who lives near you and who has the ability to read the fault codes may be a good option to help you make progress. You'd need to check the test voltages on the lambda probe and the various other items to establish if they or their respective section of the wiring loom is 'intact' and working.

Going through it methodically is the best way forward but the least easy especially when it turns out to be the last thing you check.

Hopefully, others can post some more informative replies.

As a matter of interest, has anyone checked the availability of an ABY engine loom from Audi Tradition notwithstanding the likelihood of the prohibitive cost and their 'credit card payment 'difficulty' that's been going on for months.

Best wishes.

I waiting for the 2x2 adapter to arrive and then I can pull all the codes luckely.

One more thing - it's a pretty big leak between the turbo and downpipe. The v-band can't secure enough, can that make this problem? Before I bought the car and of course before the fire the car had no problems at all.

I think it's impossible to find the loom for this one ;/

[kenkawtf]

I just pulled the codes, and beside the speed sensor i get just N75 fault and after i checked i dont even have the N75. Before the engine is warm it runs so bad that it almost stalls.

Btw - the battery i have installet is old like my grandmother - Can't start the car without starter cables from another car - can it really be that simple?

[LSG]

Shouldn't really jump your car from another car coz S2's have so many electronics that can be harmed.I think i'd Just get a new replacement bosch or a varta battery. What ever you do with the car its going to need a new battery fella and at least you know the battery isn't the problem. Good luck with fixing it. regards Lynn

[K Simmonds]

Silly question, are you 100 sure you have repaired the wiring correctly? Has the car got the correct fuel pressure regulator fitted for the software and injectors?

[kenkawtf]

Silly question, are you 100 sure you have repaired the wiring correctly? Has the car got the correct fuel pressure regulator fitted for the software and injectors?

Yes, I'm sure the wires are good. The regulator look like it had seen better days but as I said, the car had no problem before the fire. Funny thing is that if I disconnect the MAF the car runs smooth. What about the N75? Not the pressurehośe is just connected to the wg, and I can't find the N75, just the connector hanging loose

[K Simmonds]

The N75 should be located on the large MAF too Turbo hose with the longest of it's three connections going into the hose itself and the the other two from it going to the compressor housing and the bottom port on the the waste-gate, these need to be the correct way around. Without it fitted it'll just run whatever the spring pressure is in the waste-gate, what hose is currently connected to the waste-gate and which port? Only the bottom one is used on the vast majority of set ups.

I'd try cleaning your MAF terminal and tightening up the female connections with a fine pick, their notorious for causing problems, if the car runs better with it disconnected it suggests either a poor connection or duff MAF unit.

A couple of pic's of the pipe work in the turbo area would be useful.

[kenkawtf]

The N75 should be located on the large MAF too Turbo hose with the longest of it's three connections going into the hose itself and the the other two from it going to the compressor housing and the bottom port on the the waste-gate, these need to be the correct way around. Without it fitted it'll just run whatever the spring pressure is in the waste-gate, what hose is currently connected to the waste-gate and which port? Only the bottom one is used on the vast majority of set ups.

I'd try cleaning your MAF terminal and tightening up the female connections with a fine pick, their notorious for causing problems, if the car runs better with it disconnected it suggests either a poor connection or duff MAF unit.

A couple of pic's of the pipe work in the turbo area would be useful.

The MAF is brand new. The old one was shorted under the fire I guess. I was pretty sure that the N75 should be connected between the pressureside of turbo, bottom connector at the WG and before the turbo inlet, but as you can see by the picture nothing is there. I don't even know why they connected the bleedervalve on the top of diaphragm. When I connect the vcds the chip is from t+s and seems to be RS2 setup. Can also find the text (min 1,6bar)

[K Simmonds]

Right, that's helped quite a lot, sorry to blunt but that's a bit of a mess you have there! Your missing the N75 as far as I can see and it looks like someone has tried to fit a bleed valve in it's place to control boost and done a bizarre job of it, as I said nothing should be connected to the top of the waste-gate as a rule, it's a breather port. TS RS2+ chips are pretty good, I ran them in my S2 for a while and had no problems with them but that was with an N75 in place and stock pipe work, I used to see 1,8 bar max maybe a touch more with a K24 7200.

To start with I'd get an N75, fit it correctly and do away with all the blue pipe work and the bleed valve which is a total bodge and makes my eyes hurt. The ECU will then be able to control boost properly once more, it might not fix the over fuelling issue but the car will run miles better for it and it'll be a good start to getting it going correctly.

It doesn't look like you have a diverter valve fitted either, I can't see the vacuum pipe that's supposed to run to it and your oil breather system is open to the atmosphere which while it won't be causing the rich running both are issues that need sorting.

Are you able to pull fault codes?

[_ShurikeN]

Garden water hoses to carbon canister under the wing are worth criticizing too.

[kenkawtf]

Right, that's helped quite a lot, sorry to blunt but that's a bit of a mess you have there! Your missing the N75 as far as I can see and it looks like someone has tried to fit a bleed valve in it's place to control boost and done a bizarre job of it, as I said nothing should be connected to the top of the waste-gate as a rule, it's a breather port. TS RS2+ chips are pretty good, I ran them in my S2 for a while and had no problems with them but that was with an N75 in place and stock pipe work, I used to see 1,8 bar max maybe a touch more with a K24 7200.

To start with I'd get an N75, fit it correctly and do away with all the blue pipe work and the bleed valve which is a total bodge and makes my eyes hurt. The ECU will then be able to control boost properly once more, it might not fix the over fuelling issue but the car will run miles better for it and it'll be a good start to getting it going correctly.

It doesn't look like you have a diverter valve fitted either, I can't see the vacuum pipe that's supposed to run to it and your oil breather system is open to the atmosphere which while it won't be causing the rich running both are issues that need sorting.

Are you able to pull fault codes?

Thanks alot for your answer. Need to find a N75 so I can fix that issue. I don't know about the diverter, need to look after that to.

Yes, the only codes i got was of course the speed sensor, didn't start the car and also N75. But wouldn't the car be in limpmode if I have this code?

The bleeder valve is wrong for sure, already disconnected it from the top.

One thing to mention is that the car is running pretty fine when the temp is up. Revs like it should but when I release the throttle the car is rich again for awhile. Also have a leak at the connection between turbo and downpipe, can that also be a issue?

About the hoses for the canister so isn't it permanent I took what I had at home. Old ones had melted.

[K Simmonds]

No problem I like to try and help where I can, and your car needs a lot of help by the looks of it!

I'm not sure if an open circuit code on the N75 will cause the ECU to go into limp mode, it might do as that's what controls boost and a fault that causes excessive pressure could be catastrophic, I'm sure someone more clued up with electrics and the intricacy's of he ECU will be able to chime in and give an answer, I'm more of a mechanical problem man though I can do electrical work if I really have to.

That bleed valve arrangement is horrendous, they are always rubbish but that has got to be the most 'special' installation I've ever seen, an N75 will make the ECU a much happier little box and you'll have more safety for the turbo. On the subject of the turbo...It's not a unit I know anything about, do you know what size the turbine and compressor wheels are or have any reference material on it?

You can get away with no diverter valve but it considerably shortens the turbos lifespan as the comp wheel has to fight against already highly compressed air when you lift off the throttle, there should be a vacuum pipe running from the back of the inlet manifold and along down the (airbox side) inner wing to it and I can't see one in the pic for the life of me. Fitting one can only do good, it doesn't even have to be an Audi one just one that works properly, vent the excess charge back to the inlet before the turbo. Don't be tempted to go atmospheric for the sound as the MAF accounts for all the air that passes through it and a sizeable amount will be missing if it's just dumping it into space, that will cause the engine to run a little rich but not severely or all the time.

The exhaust leak isn't ideal, how much it's leaking will dictate how much of a problem it is, a slight leak shouldn't make much odd's but the noise alone would drive me nuts, you could simply try tightening up the fixing on the V-band for now and that may sort it, if not take it apart and clean the flanges until they're spotless and try refit the band, if it still leaks after that you need a new band and possibly flanges if their distorted. If it's a major leak then it will cause other running problems as it will seriously disturb the flow out of the turbo and can even cause problems with the waste gate

Just a thought but if the car runs fine when up to temperature that would suggest a problem with a temp sensor, the multi-function one located on the water manifold quite often causes problems but the one that gives the ECU it's critical info on an ABY is located on the back of the head and is normally very reliable, the 3B also has this sensor but the multi function one can cause reduced boost on these early cars, however I don't think this applies to ABY's. You need to sort out the plumbing before doing anything else as that arrangement could be causing all sorts of problems, once that's all working properly then you can start fault finding and it'll probably be something simple, it may even be that pipe work that causing your running issues.

Oh yeah, on reading back through this whole thread I notice you mention the battery being in poor condition, this will not be helping matters at all, change it as soon as you can and clean the earth point under the rear seat while your at it as well as the main connections, the ECU isn't very keen on low voltages and it'll be putting a load of strain on the alternator.

Good luck!

[K Simmonds]

Okay.... Just had a quick read up on that turbo and on our 2.2 I5's it's probably capable of between 450 and 500 BHP possibly more/less depending on exact spec, I suspect it's AR50 but it will say what it is somewhere on the compressor housing, their quite a common turbo as their cheap and give good bang for buck, however they are known to be very laggy. So the RS2 software your running is far from ideal and not a good match for the turbo, the injectors are a bit on the small side for the 1.8 bar TS RS2 chips should produce with that turbo, which if their the ones I think they are flow 410 CCM at three bar and 465 CCM at 3.8 bar and obviously a bit more again at four bar which I'm guessing is what your running but not really enough to support what the turbo is potentially capable of.

Obviously the set up did work but I'd hazard a guess your AFR and EGT values were far from ideal, not to mention it may being a bit much for stock rods, though as the boost comes in late with that turbo it's probably saving the bottom end, I'm guessing you use to get full boost around 4K+ RPM? The reason your only seeing 1.6 bar is that's the spring pressure of the waste gate, as soon as you hook up the N75 you should see at least 1.8 bar if not a little more which is going to really push your injectors as well as put more load on the bottom end and which I'm presuming is stock?

Really you need the correct software for that turbo or a remap, certainly if you want to get the most out of it but that will mean opening the engine and upgrading the rods, I'd get a wide band AFR gauge fitted ready for when it's running the same as when you got the car so you can get some idea what your AFR's are like. It would probably be a good idea to to leave the N75 disconnected and run mechanical boost until you know more as even more pressure might not be a good thing.

You need to find out the specs of that turbo, wheel sizes etc before trying to push it any harder with the RS2 software, it might well work okay at 1.6 bar with the injectors running at their current pressure but it's far from an ideal set up and a something of a mismatch regarding the chip set you have installed.

[kenkawtf]

Okay.... Just had a quick read up on that turbo and on our 2.2 I5's it's probably capable of between 450 and 500 BHP possibly more/less depending on exact spec, I suspect it's AR50 but it will say what it is somewhere on the compressor housing, their quite a common turbo as their cheap and give good bang for buck, however they are known to be very laggy. So the RS2 software your running is far from ideal and not a good match for the turbo, the injectors are a bit on the small side for the 1.8 bar TS RS2 chips should produce with that turbo, which if their the ones I think they are flow 410 CCM at three bar and 465 CCM at 3.8 bar and obviously a bit more again at four bar which I'm guessing is what your running but not really enough to support what the turbo is potentially capable of.

Obviously the set up did work but I'd hazard a guess your AFR and EGT values were far from ideal, not to mention it may being a bit much for stock rods, though as the boost comes in late with that turbo it's probably saving the bottom end, I'm guessing you use to get full boost around 4K+ RPM? The reason your only seeing 1.6 bar is that's the spring pressure of the waste gate, as soon as you hook up the N75 you should see at least 1.8 bar if not a little more which is going to really push your injectors as well as put more load on the bottom end and which I'm presuming is stock?

Really you need the correct software for that turbo or a remap, certainly if you want to get the most out of it but that will mean opening the engine and upgrading the rods, I'd get a wide band AFR gauge fitted ready for when it's running the same as when you got the car so you can get some idea what your AFR's are like. It would probably be a good idea to to leave the N75 disconnected and run mechanical boost until you know more as even more pressure might not be a good thing.

You need to find out the specs of that turbo, wheel sizes etc before trying to push it any harder with the RS2 software, it might well work okay at 1.6 bar with the injectors running at their current pressure but it's far from an ideal set up and a something of a mismatch regarding the chip set you have installed.

Thanks again for great answer.

I've talked with the guy who built this and he said that they did take away the N75. I didn't ask why but as you say - maybe the car will be in limpmode - but different from when I disconnect the MAF. If I disconnect the MAF I can't rev over 2500 when I open full. MAF connected it's not a problem.

About the turbo I can't say much. It's a old turbo from a John Deere. I think it's a k27? Will see if I can see the label.

The thing is that the car was running great before the fire. No problem with overfueling or lack of boost. Seen a couple of clips just before the fire.

There is no diverter valve installed, just a BOV which I know isn't ideal but can't change it right now. I do hate the sound to

Anyhow, the only difference between before and now is my lovely gardenhoses to the canister and those cables that I fixed - the rest is exactly the same. Maybe the ECU got something wrong when the cables was melted together?