Recently finished a 2.0 conversion on my Mk2 using an ADY bottom end, new gaskets belts 1.8 dizzy with TSR adapter etc. All the timing marks & TDC set, got a great spark & fuel but she refuses to start?? Any suggestions greatly appreciated as i'm not sure what to check next. thanks D
ok, areyou sure the dizzy is lined up to tdc properly? it will spin freely when the timing belt is loosened. does the fuel pump prime for a couple o seconds when the key is turned 1 click?
the dizzy spins freely, even tried rotating it slightly while turning her over, the best I got was a cough then a back fire then nothing. Local mechanic dropped by to double check timing etc, everything spot on. Fuel pump is priming & replaced the dizzy cap arm & leads - no improvement. really appreciate your help!
wait what, it spins freely with the belt on? I think I know what you've done. Have you fitted the dizzy adaptor ring but left the original dizzy gear on? because if so, that wont work you need to fit the 2.0 dizzy gear if you can find a MK3/Passat 2.0 8v 2e dizzy, that will drop right into your block and work with the MK2 managment
i didn't explain that very well, i mean the dizzy body turns freely. rather than batter the pin out & change the dizzy drive wheels over i swapped the whole shaft over including the drive wheel from the 1.8 - could this be the problem? i know this isn't the usual way people do it but all the measurements are the same & it saves your knuckles..
erm, maybe that'll work. only thing is are you sure the oil pump slot is fitted to the dizzy ok? I'd spin engine over with rotor arm off too, if the rotor spins with engine then you know its ok, but the oil pump drive needs to be double checked still. Also double check the rotor arm lines up with the dizzy housing notch when cam is at tdc, plug #1 lead in where the rotor points and set the firin order to 1342. since it ran ok before i guerss the sensors should be all ok, but if not done before the blue sender is worth replacing with a newun from vw.
cheers john but i've done all you've advised previously except the blue sensor. where is it, whats it do & why would it stop it starting please?
cool, sorry if i sound patronising but its worth mentioning the blue sensor is in the plastic flange on the front of the block (or its a white threaded one if you have the earlier digifant with a metal front flange) This sensor tells the ecu how hot the engine is, if its bust it will stop the car starting as ecu thinks engine temp is higher/lower than it actually is! My sensor went in a really dodgy way, 1st turn o the key it would never fire, no matter how long you held it on starter. It would always fire without fail! New sensor and all was well.
no offence taken, any advice is more than welcome & i know you chaps are clued up. i used to have a Passat Gt that developed similar simptoms overnight, ended up parting with it for peanuts outta frustration because no-one could it get it going - i'm not doing that again!! I'll change the sensor & see what happens, cheers
remember reading about bad ecu earth causing similar symptoms.. easy check just take board out and look for scorching
hmm, have a look at the spark plugs maybe? did a head swap on a polo and it wouldnt fire. all the plugs were gunged up, they were fine before I took the head ok, I'm guessing general crud buildup in the bores when I was cleaning everything fowled them up.
did a compression test today & all was o.k but, checked the oil which stank of petrol. after trawling through the threads i'm presuming that the ECU has blown causing the injectors to stop open - is this correct & has anyone got a spare ECU? cheers
go through on ebay for 20-30quid so check first. youll need to remove seven small screws on casing(think 3 on plug side 4 on opposite) +then board will slide out from back. never found a picture of said scorching but apparently pretty obvious if its gone. also not sure what path the ecu earth takes? maybe check earth ribbon from bulkhead to rockercover
turn the key 1 click. if pump runs for a few seconds & stops, ecu is prob ok. if pump just runs continuous then ecu is blown due to bad gearbox earth.
close to giving up now & putting it on ebay. fuel pump primes, ecu o.k, temp sensor o.k, timed correctly, new plugs dizzy leads etc - don't think theres owt else to change or check
bit of a long shot but apparently timing can still be out with all timing marks lined up correct when flywheel bolted on in wrong position.. check piston 1 def at tdc with screw driver down plug hole. also i once mistimed my engine by setting flywheel to 6degs btdc mark rather than tdc mark to right of it. wouldnt think its a fueling prob as top end is basically as it was before conversion but check all stuff youve disturbed ie fuel lines arent leaking, any plug wires havent got split. but if theres fuel and strong spark and cam timing is correct your only really only left with ignition timing. wot about dizzy work you did? maybe switch back to original shaft + change drive wheel... a job that can be done on kitchen table which is big bonus in this whether
could still be the ecu i guess, one thing you could check is the wiring to the fuel rail. it gets 12v from the fuel pump relay and is earthed via the ecu, if the earth wire has shorted to ground the injectors will stick open or perhaps the ecu has shorted inside? give the gearbox earth a good going over, maybe upgrade to the later earth location if yours is an earlier digifant. some time around 1990 the box earth was moved to a stud on the rear gearbox -> engine bolt, previously it was connected to the gearbox bracket.
I've been having this problem too, but on a standard 8V 1.8 engine (posted on here a while back for advice, but car still not going). Any resolution to this yet Dink? I ended up changing a load of sensors, tried three different ECU's and ignition modules, but the car still refuses to start. I tried it with easy start a couple of weeks ago and it tried to run on 2 cylinders, but once I hooked up the fuel supply again it didn't want to know. It's currently in the garage with the cylinder head off, while I give it a recon. The compression was a bit rubbish on two of the cylinders, but no obvious sign of a head gasket failure once the head was on the bench!!
