Help me get my VR running right

[PhatVR6 0]

Getting p1ssed off with this f*cking thing now.

 

Right, here's the story. When I first got it running, it was only running on 5. number 6 injector wasn't opening (took me ages to find that out!!!) . put another one in, car ran mint and pulled really strongly throught the rev range, with a noticable kick up in power coming in at 4500rpm.

 

I gave my mate his AMD ecu back and I've just got a standard one on there now. I've noticed a slight flatspot at 4000rpm since I did this, and obviously it doesn't pull aboue 6500rpm anymore

 

After about a week I strted getting an intermittent misfire. the car would run fine from start up, but after a short whille and a couple or prods on theloud pedal it would start to splutter a bit under load. then it got worse. it'd idle fine, and run fine at part throttle, but if I booted it it'd sound like it was dropping onto 5 cylinders. I though this was uel delivery related, as the pump had been whining it's knackers off after I installed the engine and I'd had it in bits a couple of times, so I fitted another one, but it made no difference at all. then it dropeed onto 5 permanently. after about a fortnight of driving it like a bag of spanners (yes, I know, but I couldn't find the fault) I noticed that number 6 plug lead was arcing out on the head. I changed it, and got it running on all 6.

 

I thought it was running alright (after driving it for 2 weeks on 5), but went to york dragway and ran a feeble 14.9, getting worse throughout the day. The more I drive it the more I notice it's faults. It takes a lot of cranking to start, and usually stalls stright afterwards too. It cuts out regularly when slowing down. theres no throttle response, when you floor it it hesitates then goes, then theres the big flat spot at 4000rpm, but the power just doesn't come in above that like it used to, it's as if it gets to about 160bhp then hits a wall and won't prudce any more power no matter what the revs are doing?

 

I had vag-com on it and it came up all clear, but can't check it at the moment as I haven't got it anymore.

 

coil pack and plugs are brand new, I've tried a different MAF, blue temp sensor is brand new.

 

VGI isn't on at the moment. and I have an early passat manifold on it, so the intake temp sensor is unplugged (ECU defaults to 60C).

 

Go some new leads and injetors coming next week, other than that, what else can I check or change? I'm completely at a loss as to why it isn't producing power like it should? so much so, that I've given up on the car and decided to do my mk2 golf up again.

[Kevin Bacon 5]

Are you anywhere near a rolling road? Might be worth running it on the dyno with the VAG-COM measuring blocks screen at the same time (or VAG-Scope) to see if you can suss out what's going on?

 

Apart from checking the fuel pressure at high rpm and injector flow rates, I can't think of anything else as you've rebuilt the engine from the ground up........

 

Gotta be something silly. As thorough as you have been, you may have overlooked something. I know I do all the time.

 

Those symptoms are what you get with a dead MAF and/or lambda probe but you've been down that road already. Worth trying brand new ones? At least you can them back if they make no difference.

 

K

[h100vw 0]

Take it to Kershaws mate, you know they'll fettle it.

:mrgreen:

Gavin

[24V Renshaw 0]

Haven't really played with the VR much, but is the ECU vacuum fed? As that is exactly the symptoms I had on the G60 when the vacuum pipe to the ECU was tired.

 

Doubt it, but it may help.

 

J

[PhatVR6 0]

nah, not vacuum fed.

 

I'm going to replace the PFR and it's vaccum hose to see if that makes a difference. I think it's fuel related as it stinks of fuel when you slow to a stop, and it's doing crappy MPG too.

 

didn't really want to resort to taking it to a rolling road place just yet.

 

haven't got vag-com anymore, it was on loan.

 

haven't got a fuel pressure guage or a compression tester either.

 

need to wire up my A/F gauge and see what that' reading.

[h100vw 0]

Not much to go wrong with an FPR unless the diaphragm has got a hole in it or it's the wrong FPR all together. Might be worth buying a fuel pressure gauge.

 

I don't use mine often since getting rid of all my K-jet motors. I did use it most recently after making my 3.5 BAR FPR from std one. My guess work was spot on. :mrgreen:

 

You say it cuts out on the overrun, does a VR have a closed throttle switch, maybe that's gone??

 

Gavin

[PhatVR6 0]

it only has a throttle potentiometer.

 

i think the stalling might be due to the flywheel, it's so light that the revs drop too fast for the ISV to kick in. sometimes it keeps the engine running, sometimes it stalls. that's no big deal though, it's the power loss that's bugging me.

[h100vw 0]

Could be that the throttle pot is bad then. If you haven't checked that with a DVM you should. No idea what it runs to/from but if there are dead spots on it that could be causing some of your snags.

 

You need to check that it increases or decreases from closed to open smoothly. Any sudden jumps to open or short circuit would indicate a problem. Bad info to the ECU that it cannot or badly interprets would make it run badly.

 

The ECU would probably expect to see a certain value represent a closed throttle. Maybe Kev knows what that is? The pot may need adjusting to get that right?

 

There is fella always selling VR6 engine manuals on ebay, I reckon it would have the right info in there.

 

gavin

[PhatVR6 0]

I have another throttle body actually, I'll try that.

 

already got a russek manual, doesn't tell you stuff like that I don't think.

 

but I do have a genuine vag manual for the engine and the motronic system, so I should be able to check.

 

f*ck me, I haven't even checked to see if the throttle cable has slipped or something as silly as that.

[Kevin Bacon 5]

Even VRs with the stock flywheel stall Paul, so I doubt the Fidanza is causing the stalling.

 

The throttle pot needs to be at 14 degrees or less for idle and 90 degrees for maximum throttle. I think overrun kicks in at around the 15-16 degrees mark, so the transition is very tight and I personally think that's why a lot of VRs stall....bad programming. Sticking ISVs doesn't help matters either as they seat right above the exhaust manifold absorbing tonnes of heat.

 

VAG-COM is useful for that. The measuring blocks show you the throttle positions. Check the angle at idle and make sure it's 14 or less and shove a brick on the throttle and make sure you're getting the full 90+ degrees too. If not, check the throttle cable.

 

And err yeah, the engine obviously needs to be off when doing the above, LOL!

 

K

[h100vw 0]

That VAG manual will have the specs in it for sure. Check and set up the one that is fitted before you consider replacing it.

 

The VAG manuals have a massive amount of troubleshooting info, just need a 1551/2 for a lot of it. VAG COM should be able to give you the same info though.

 

Gavin

[PhatVR6 0]

I'll buy a laptop pff ebay today so I can get vag-com up and running for next week.

 

don't fancy taking it to germany next weekend with it running like this.

[h100vw 0]

Was it more than 95 quid? :lol: like my GT

[PhatVR6 0]

a frigging throttle pot is about £95!

[Kevin Bacon 5]

Shouldn't be. I paid £45 for mine last year. VW have superceded it with a newer version, which requires shorter bolts and aren't supplied :roll:

[PhatVR6 0]

Borrowing the AMD ECU again tonight, and fixing the exhaust. I'll see if it makes much difference....

 

going to germany on thursday night...and still no sign of the new leads :mad:

[Kevin Bacon 5]

Off topic content removed at thread owner's request......

[PhatVR6 0]

Right, some progress at last. My mate forgot to bring the AMD ECU......arse. but, another mate brought along vag-com. checked for errors, there was a fault logged for the intake air temp sensor understandable as it wasn't plugged in), one of the knock sensors (short to ground) and the engine speed sensor (implausible signal). cleared them all, none came back. went for a drive out, pinking it's knackers off. checked errors again, same. so basically what it was doing, was pulling the timing as soon as it flagged up the intermittent knock sensor fault, hence the flat performance.

 

plugged inlet air temp sensor and tucked it in amongst the injectors (there's no hole in the manifold for it). and went for another drive., it still stalled, bringing up the engine speed fault again (which I'm not too bothered about, as it's a borrowed sensor off a 1992 vr6 anyway, will put mine back in tomorrow), and I know I repaired the knock sensor as it'd been damaged (the loom was cut).

 

so, I reckon if I put my engine speed sensor in (or buy a new one), buy a new knock sensor, and get that intake temp sensor back in (i.e. when I fit the vgi) and get a copy of the AMD chip it'll be A OK. :D it now pulls a bit harder, runs a lot smoother, does 30mpg, and actually feels like it has some top end power. still not 100%, but it's getting there.

 

Should be getting my own laptop tomorrow too, so I can reset it at will whenever that fault crops up until I can get a new sensor.

 

hopefully...

[Kevin Bacon 5]

Good news!

 

The engine speed sensor is expensive, £140! I had implausible signal from my engine speed sensor too and although the engine still started and ran, a new sensor was the only way to get rid of the error.

 

You'll be pulling mid 13s again soon :wink:

 

Have you got the 268 cams on at the moment? What are they like with a stock manifold?

[PhatVR6 0]

yeah, I know the price of it..... :roll: :cry: hence why I borrowed one instead of buying one. I hope mine is OK...I guess this explains the stalling. if the ECU doesn't get a signal from the engine speed sensor for one cycle that's i, it doesn't know what to do so it cuts out.

 

268's run fine with the stock 2.9 manifold, not so with the stock chip though. you really need a specific chip to get the most out of them. luckily for me, the AMD chip my mate has was for a 1994 2.9 running a schrick vgi and 268's, so no wonder it works so well! I just need to get hold of a copy of it.

 

I think 13's is asking a bit much from the lardy old corrado to be honest with you. but a sub 14.5 should be possible. it did well to run a 14.9 running how it was, it felt flat as a fart!

 

can't wait to get the new lead, injectors and vgi on now, I'm missing that torque badly.

[Kevin Bacon 5]

Ah...a chip for a VGI and 268s you say.... just so happens I picked up a set of 268s recently...... :lol: Any chance of a copy of this map?

 

Do you lose much in the bottom end with the 268s?

 

Oh yeah, I forgot you pulled those 13s in your stripped MK2. Yeah the C is a fair bit heavier.....base model VR is 1210Kg....with leather, air con etc, that climbs to nearly 1240Kg..... lardy as you say! No wonder those Clio 172s are hard work, they're only about 1080Kg!

 

Anyway, I reckon you're almost there. Glad you didn't give up!

[PhatVR6 0]

I'll see if he can do a nother chip when he does mine. not sure what's involved with the whole process to be honest with you.

 

no, you don't lose any bottom end at all, especially not with the vgi on there oo, they are a perfect match.

 

I pulled 207BHP with the old engine, and that was just with a superchip, not the AMD one.

 

1200KG is fairly lardy. my golf will have been closer to the 1000KG mark I reckon. never had it officially weighed though, just a guess.

[Kevin Bacon 5]

If your mate has all the necessary equipment, it will just be a case of 'flashing' a couple of blank chips once the code from the AMD one has been copied to the computer.

 

I read somewhere about some people working on a way of programming the ECU 'on the fly' using VAG-COM. Apparently it's already been successfully done to an Audi. Anyway, that would be good, but a long way off yet.

 

I'll defo have a copy of the chip if he can suss out how to clone them.

 

Good news about the Schrick 268s.... just what I wanted to hear :lol:

[PhatVR6 0]

Don't you still have to have a socket soldered into your ECU though? or do they already have one?

[Kevin Bacon 5]

Yeah his and my AMD ones have already had the chip holders soldered on. Yours will need doing though. If you've still got his AMD ECU there, take it apart and have a butchers. Not a lot to it.