grr major vr6t help wont run right

[powernut 1]

2.8 vr6 turbo runing shit...e

something not right just carnt work it out , heres things ive tryed,

the engine will start with revs high and slowly come down to idiol which then has slight miss, and afr gauge will go learn then rich and engine will cut out , when trying to drive it ,it will intermitanty do a odd inlet back fire?

things ive changed,

coilpack,leads, plugs,

clyinder head removed new valve guilds and re ground valves

another maf, feul reg, crank sensor , 3 fusebox relay,crank sensor,

timing removed and checked/algined,new exhaust/inlet gaskets,

injectors, earth straps,complete engine loom replaced,

tps,lamda,thottle body and gasket,

ive perfect compression on all six clyinders,no fault codes in vag,

carnt work it out , only other things ive not changed is the alti?its chargeing but its a 70amp not a 120amp will this make any differnce

[cabrioman 6]

mapping issue ????

[UnitedMotorsport 55]

mapping issue ????

PMSL

[powernut 1]

tryed the ecu on my friends vr6t and it starts idiols fine 14.6/7 and steady 11.5 in boost , just noticed my alti is a 70amp. my freinds is 120amp , yet charges fine

[legvw 0]

It does sound like something to do with your ecu/map.

Also, if the ecu doesn't receive the correct voltage it will 'play up'. You could try to see what voltage the ecu is getting when the engine is running. And possibly try another alternator? They can do strange things when they're not working correctly.

[bungy 2]

When the car is running, what voltage are you getting across the battery terminals?

[jims13 6]

so whats the difference, between your mates car and yours, if it works fine on his car , then it points to your hardware, not the ecu ..

you need to check for airleaks, etc etc. also you say your removed your head.. are you sure the timing is correct ?

again, if the ecu works fine on your mate car, then its not that..

and it would point to something you have done or havent .

[FishWick 21]

Is that your car in your Avatar? Looks like a 24V Turbo MK1?

Changing the alternator won't make a difference if the 70A is charging. What car do you have? I doubt it will ever pull more than 70A unless you have 4 x 100W spot lamps or something.

Look at the batt voltage in VAG-COM. If it's ~14V when cold and ~13.5V when hot, it's working fine.

ECU and injectors won't start playing up until <10V is seen.

Given what you've checked and replaced, it's bound to be something simple you have yet to spot. You just need to take a methodical approach and go back to basics.

You say you replaced the entire loom. From a donor car or brand new from VAG?

[powernut 1]

replies many thanks all for theadvise a these issuiese have been on going for a while , i will plug vag lead and do a small video off the settings off 001 to 007 regards ecu and wireing ive checked pin for pin so i know its correct , and tbh im getting really fed up heres the spec of the engine

hx40 turbo

46mm external wastegate

50mm blow off

wossnerr pistons

sp high beam rods

2.5 pipe work

double front mount cooler

640cc tunie,4bar

arp head /crank studs

started the car alti shows 13.8 cold and 13.5/6 warm

this engine is fitted in a mk1 caddy pickup (the pic at the side is mine which used to have a r32 hybrid

realy werid as sometimes it will start and idiol fine then suddernly has a hissy fit

checked fuel pressure this morning shows 4bar when vac pipe is removed rises at bit

then made a 4inch boost cap and pressureized the dam system hopeing to have a massive air leak again ,buggar all, so im 100percent happy engine is sealed correctly regards air leaks,timing is correct and double checked crank mark,rear gearbox tooth mark , arrow on oil pump drive and both top camshafts algin correctly ,

i just carnt think what to do ,many thanks for advise guys ill take a engine pic and vag video if it may help

[powernut 1]

so whats the difference' date=' between your mates car and yours, if it works fine on his car , then it points to your hardware, not the ecu ..

you need to check for airleaks, etc etc. also you say your removed your head.. are you sure the timing is correct ?

again, if the ecu works fine on your mate car, then its not that..

and it would point to something you have done or havent .

[/quote'] your right but what ive not not a friggin clue

only differnce i can see on his is the turbo sits opersite way with the maf intake pipe going right around the engine to were the battery usely is on a mk3 golf,

[powernut 1]

his car has idenical 4bar emmprom with same engine spec including injectors, large maf houseing ,and same thottle angle in vag ,ill have to try another maf , yet this seems to be working with no fault codes showing as i just checked this moring ,

[powernut 1]

right guys , here a pic of the engine

ive done a few short video clips off the mobile , first idea was start engine remove battery lead and blue exciter wire from the alti yet this is what it shows , is this normal, ignore my noisey tappits awaiting for new set to arrive ,,

View My Video

[mikey 0]

Just a thought but are ur leads arcing out to ur inlet manifold found that to be a bit of a prob on mine ?

[powernut 1]

ive tryed 2 sets first set were red and now these black ones which i carnt see any arcing at night under the bonet , im thinking ive a wireing alti fault at mo , as im sure the alti should not charge withthe instrument blue wire disconected from the alti , yet when i removed mine im showing showing odd voltage in vag and on the car, bloody confused

[FishWick 21]

That's a nice short runner intake you've made there, well done fella.

My guess is the MAF is too close to the turbo. Do you have any stainless mesh over the 4" tube to straighten the air? Pre-MAF element end of the tube.

Think of the turbo compressor creating a whirlpool as it sucks in air and the middle of the whirlpool has less air than the edges, which is where the MAF element sits. In the middle, getting less air!

Does it idle OK with the MAF plug pulled?

As a suggestion, try the stainless mesh, then move the MAF and filter as far away from the turbo as possible, then try a new MAF. Brand new, not a s/hand one.

Where are you based? There might be a VRT owner near by who could lend a hand. Someone else might spot something you haven't seen. Sometimes you can't see the wood for the trees!

Regarding your Alty, has it ever had a new diode pack put in it? They come with excitor resistors these days, where as the original did not, so if the blue wire is unplugged or the dash bulb fails, it will still charge.

[powernut 1]

hi kev many thanks for taking time out and help , i replaced the alti today for a 120amp one from a 4motion golf charging better ,but hasnt made any differnce there , but i know the alti was fine from adonner engine , next thing , egards the airfilter , odd thing is , ive run this in the past with no afr issuises etc in the past , but do think its a problem , ive tryed getting the maf sensor away as mutch as i can due to room issiuses, and adding a air flow straigher airfilter which are supose to help ,

if i start the engine it will rev up to around 1500/2000rpm then steadly drop to idiol dose this cold and warm , i know the mafs working as its showing 14.5/7afr if i unplug the maf while idioling its dosent make mutch differnce other then revs slightly rise and runs a bit richer around 10/11afr , ive seen new ones at 43,00 on ebay so i reckon worth trying one just to be safe , as i never tryed my filter on my friends car tbh , so youve a good point there , id like to have a long intake pipe re routed again theres no room , due to way its been piped and were exhuast runs , plus in a mk1 theres a little less room ,if u can work any ideas then fire away im all ears ,lol

[DanH 1]

cant help but sure ive seen this engine bay before? if its the one im thinking of LOVE IT! home made hotside and exhaust exits out the wing

[powernut 1]

yep thats me ,

ive have the engine idioling like this not so long ago , changed alti made no differnce ,, grr so stressfull

http://tinypic.com/r/nmdruh/7

[FishWick 21]

Is your engine OBD1 mate? Well you certainly know what you're doing and have covered all the bases, so it's difficult to know what to suggest next!

If the AFR changes when pulling the MAF, that means the ECU was using it to meter the fuelling and hadn't bypassed it, so that's a good sign.

So after the idle valve has done it's thing and the revs drop down, that's when it all goes to schitt?

[powernut 1]

hard to explain has differnert things happerns , it always starts fine from cold and instantly revs up high then slowly drops to idiol,as the engines warming up afr starts to get worse rich/learn etc so i did assume it was maf related ,yesterday i add a 1metre lengh of 4inch tube and placed the maf inside with a mesh over each end , and didnt make one bit of differnce tbh ,something i have noticed , i removed the idiol control valve (evern thow ive bloody 5 here all do the same ) but left it pluged in to save a fault code showing in vag, and blocked both inlet and boost pipe pipes off and adjusted the tps so the car would idiol , and went for a run , and drove better but kept doing intermitant pops/backfires in the inlet and exhaust , and ramdonly cutting out at juctions, so i replaced it re set the tps trim to 12.5 and then shorted both battery leads and turned igition on and left it for 15mins before switching off re fitting then starting the engine to clear any issuises which might have been stored on the ecu , car started and revs droped , but the rough ,intermitant pops/backfitres are still there as i try to accelerat coming into boost /or attempting to pull thew it , i can see the vacum/boost gauge moveing when i get backfires etc, ended up fed up so , thew it in garage and shut door before i end up cutting it (which ive ended up in the past doing,thew temper)

like i say ive had all the valve seats,seals done, new gaskets, hang on noticed ive not checked changed the injector seals , but saying that , i carnt hear any air leaks when i tested the engine for boost leaks ,

,

the engine loom is obd1 but ive converted it to a 4pin maf instead of the useal 5pin maf as im useing a us spec ecu due to emprom tunie , (again same as my friends ) but ive not got the mk3 vr6 fusebox just the 3 relays 167 feul relay, 53 lamda relay and ecu control relay (think its called 109 rest arnt need to run the engine , only 2 spare wires left from the ecu are for the aircon pump which i dont have

also noticed say im trying to drive at 40/50mph then gear down with no thottle for a few seconds then touch the accelerator to accelerate the engine will go instainly learn 21.7afr like a flat spot then sputtler and go rich then back to normal 13/14 afr why im unsure , again everything ive checked and tested runs fine on my friends car ,

[FishWick 21]

When the rich / lean thing happens during warmup, is that at or just after 70 deg water temp?

What size injectors are you using and what is the tune set for? Is it the C2 42lb tune? I see you're running the rail at 4 bar, but should be 3 bar if it's the 42 tune. 4 bar means 15% more fuelling the lambda is having to take out at idle and part throttle.

It's just a guess but it kind of sounds lambda related.

Don't cut it up!! I'm sure we'll get to the bottom of it eventually. I've been through all this several times but in the end I just went standalone because I was fed up with MAF sensors and not having full control over the ECU and tune.

[powernut 1]

no mines has a custom tunie 560cc injector runign at 4bar equals 640cc tunie , it will do this learn/rich thing when de accelerating hot or cold , mostly warm tbh on idiol, as i also run a 70 thermostate everything idenical to my friends spec ,,

i tryed a 3bar and runs too learn , i know it carnt be the tunie, injectors fuel pressure as all run well on the other car , wireings been checked pin for pin many times, ill await till the maf comes may help?

ive also a megasquirt ms2 which ive made a loom to plug into the stock obd1 loom and added a 38psi map sensor along with laranch control, etc , just not tryed it yet , as i pref a safe stock ecu as the ms dosent have knock sensors ,,

[FishWick 21]

640cc, going for some tasty boost pressure then!

Yeah OK, let's see what the MAF does then.

With your setup I'd probably be using the MS anyway tbh. You can kill an engine just as easily with Motronic as you can a standalone!

I've done 4 years and nearly 60K miles with standalone and no knock control. No pitting on the piston crowns. If you get the timing right, you don't need knock :-) Obviously you'll need a second map for 95 unleaded but that's no problem.

[powernut 1]

640cc' date=' going for some tasty boost pressure then!

Yeah OK, let's see what the MAF does then.

With your setup I'd probably be using the MS anyway tbh. You can kill an engine just as easily with Motronic as you can a standalone!

I've done 4 years and nearly 60K miles with standalone and no knock control. No pitting on the piston crowns. If you get the timing right, you don't need knock :-) Obviously you'll need a second map for 95 unleaded but that's no problem.

[/quote']

yep ur right ive managed to knacker a few in the process , are u runing ms2 on yours?i removed it as unsure regards getting everything set correct

[FishWick 21]

I'm running DTA S80 mate.

If you want to run your standalone I can send you some numbers that I know to be safe and work well.

Any progress with your running problem?