Crankshaft Timing alignment 6' BTDC and lacking power

hey

So, got a GTI DX engine - trying to work out why all of a sudden it started running like trash - happened all of a sudden so not sure what caused it to start.

on the job-sheet today was setting all the timing, including distributor. got the gearbox inspection plug out by smashing it to bits with a long chisel as it was stuck fast. - used the guide at http://www.cabby-info.com/Files/AdjustingTheTiming.pdf

Anyway, I found the TDC mark but NOT the 6'BTDC mark - I rotated it a few times to check and confirmed against cam gear timing marks etc but it's not there?? (i found the dot, not the V cut)  - anyway, I went ahead and proceeded to re-set the distributor to TDC and then I planned to do the rest by ear and by guessing from looking at photos where 6' should be it should be.

unplugged the vacuum from the advance, and tried to turn the revs to 800/900 but even with the idle adjuster I could not get it below 1000 - so went ahead anyway and plugged in my timing strobe - When I had it set to TDC it sounded TERRIBLE, it was misfiring and wanted to shake itself out of the engine bay, so I moved it to where 6' looked like it should be and it sounded a bit better but still rough, then I rotated what I would guess was twice the distance from TDC to where the 6'BTDC mark should be and it sounded great. - but it's so far advanced you can't even see the TDC mark at all.

took it for a spin and it was much better BUT it feels like its lacking acceleration now, torque feels fine, rides well and I cant feel it missing any beats but it's just not picking up the revs and it seems to slow its pickup substantially past 3000 revs.

Any advice on what to try next? - I was going to play with the mixture a little by ear to see if I can get it running a bit smoother by ear then at some point I think i might have to take it to a garage to get it on a CO meter test done on it and set it up properly.

whats your thoughts? - any other bits that might be causing power loss? i have yet to test the injectors but would this cause power problems past 3000? i would have expected if they were blocked then they would cause problems constantly?

so far to try to fault find my engine running problems I have;

• changed fuel filter
• changed all fuel lines from tank to pump (8mm and 10mm reinforced type)
• tested lifter - 500ml in 10 seconds!
• tested fuel pressure in the engine bay - 92psi when engine running then holds 44psi for 5 mins after it's off.
• blown out all fuel lines with compressed air and checked every single fitting for blocks etc
• I put in a brand new fuel tank about 1 month ago
• repositioned and cleaned out swirl-pot
• pressure tested - results;
• Dry test135-115-110-135Wet test145-130-135-155

any advice welcomed!!! it's driving me nuts
  

Are you using fresh high octane petrol (97+ RON) such as Shell VPower 99 RON. When new the timing was designed for 4 Star 97 RON petrol not todays 95RON unleaded. Also if the fuel in the tank is 6+ months old it probably gone a bit stale.

 

When I read this I remembered reading somewhere that new flywheels don't have the timing mark, you have to put  one on yourself to match the engine, according to Haynes 6 deg equates to 12.5mm which seems right.
Have a look at the plugs, if they're all a decent colour I would double check your timing belt, also 92 psi fuel pressure seems high.

hey - thanks for the replies.

Yep, it's running on premium unleaded and it's brand new fuel sitting in a brand new tank and also going though brand new lines.

fuel pump if i remember right on the injection models shoudl be rated for 120psi ??? so i think the 92 might be fine.??

fly-wheel, i was thinking it might be new and that's why - thanks for the advice on the Haynes i will check mine now to see what that and the Bently say as to distance from that first TDC mark.

the timing belt has been checked three times in the past week - as in both covers off, re-timed , tensioned and checked by turning by hand and by taking it for a spin and checking its not somehow slipped a tooth - all fine - checking the marks when it's running with a timing light also confirms its all timed correctly.

went for a long drive today, pulled over a lot with a 13mm spanner and a 3mm t-bar hex and had a fiddle with the dizzy position and fuel mix a bit then drove for a bit and did the same again, I can't say it made any improvements.on what i had done by ear on the driveway

the bit I am struggling with is it's not missing a beat, all cylinders firing, nice smooth ride - no noises, idles fine, starts up the first time, exhaust gasses look and smell fine, fuel pressure is good - the only thing i am thinking now is air, but i have just cleaned the whole manifold and throttle body so i can't see that being the issue??

thanks for the thoughts - i know its not an easy answer but hearing your thoughts and opinions helps me decide what to try next!



 

From Brokevw.

There was some one that has the actual measurement of the distance between (0) stamp and the hash…. so you could use a marker to make it at 6 and know it is 6.

sounds very complex and technical mate

so why not forget about the flywheel causing
issues it has nothing to do with the timing

Hey

The flywheel was where I was going to set the 6'BTDC  but I have parked that for now as it's clearly a new one as I expect at some point it's been changed with the clutch.

Did a leak down today and all four cylinders came out with 15% and that's well within the tolerance - although I could hear the air leaking past the piston rings and coming up the oil dip stick I believe that's normal.

Had a colourtune on it today, super inconsistent burn at idle, getting deep oranges, mild yellows and nice blues .


The thing that surprised me was the mix screw, as I had the colurtune on it today I gave it a bit more of a turn than normal to try to dial in a nice blue but turning it hardly made any changes at all to how well it was running or to how well the mix was burning at idle or at high revs  - the only noticeable difference was when it was super rich it was sending out some backfires and snap crackle and pop exhaust notes that a boy racer would be proud of so the fuel was obs not completely burning up and was getting dumped into the exhaust.

Made a injector puller today so will get them out and measure the spray patterns and how much they are delivering. I also think I am going to strip down the intake and vacuum lines again to check for leaks and Its really starting to bug me now.  Even when messing again today - engine runs great, it's just lost its guts.

As much as I hate to say it and don't want to admit defeat I think I am not too far of taking it to a garage to get it on a rolling road with a old boy mechanic tinkering with it - luckily found one not far from me that has good reviews on the mini and kit car forums so if I can't get the the bottom of it then hopefully he can!

But for now, injectors are the next bit to look at….

just to double check you're setting the ignition timing to 6 degrees with the vacuum line to distributor disconnected and plugged?

as above you make your own marker if need be by measuring from the TDC mark 12.5mm. The way I did it was snap the end off an old ruler so it could fit down the hole in the gearbox, with a piece of string taped to it so no chance I'd drop it inside.


whats the part number on the distributor also, might not be a GTI one. also if its pattern part get shot and replace with genuine bosch, the pattern ones sometimes aren't made correctly

Hey! Thanks for the reply John.

Yes had vacuum off and blocked and it's a Bosch distrobuter.

I have actually just got back from a local garage (AB Garage, Harwarden) where I had a old boy mechanic look at it - he had experience of the K-Jet system ad was actually workig on one on a XR3i K-Jet the same day i was there - he works on old cars can't recommend him enough as he tracked it down and fixed it in literally 30 mins. - It was $hit in the fuel lines, I  think I had eliminated the majority of the blockages and gunk - I had cleaned the K-Jet metering head and air box etc as per the guides on cabby info, blown out and replaced every fuel line, new filter and checked all injectors and Banjo's etc.

He traced it to the warm up regulator, small mesh inside was partially blocked and it needed a clean and new O-Ring so he stripped and cleaned it, went back in and problem solved!

Had it on the rolling road with CO monitor connected and he got the fueling and timing all set - and it's running better than ever,

The only thing now is, to get it running it's best and putting down the best HP he had to set timing to 3'BTDC rather than 6 - and he couldn't get it to output more than 83BHP, and it was making quite a bit of smoke while being thrashed.

To me it's driving better and smoother than ever and it's putting power down well and feels the fastest it's been since I had it, but obviously it's missing 30 ponies somewhere and I expect it's the rings / bottom end.

So I think I am planning to take the engine out in the new year and do a full clean down, decoke and rebuild, port and polish, regrind valve seats, check bore and re-hone etc and maybe stick on a new exhaust manifold. I am not looking for mega HP but I would like it to be putting down figures in the 100BHP range