T/D-N/A injector swap

[Rabbit TD]

Can the 1.6 T/D injectors be switched to the 1.6 N/A injectors just for diagnosing a possible leaking injector problem and if they can be how will it affect any long term running of the engine?  It has no more than about 11 psi boost right now but it seems hard to start after I shut it off and this is a new engine with plenty of compression, timing at 1.0 m/m and no leaks at the pump right now and the glow plugs and advance lever work fine.  It does this after just sitting for maby 15 min in the garage but the engine runs great with no smoke at all to amount to anything.  I was thinking about putting the N/A injectors in which I know are in good shape just to see if it made any difference.  I did take the T/D ones apart and clean them and lapped the surfaces and they do not leak externaly.  The pump settings have not been touched.  The engine only has about 1 hour on it so far but runs great in all other respects.

[jtanguay]

Can the 1.6 T/D injectors be switched to the 1.6 N/A injectors just for diagnosing a possible leaking injector problem and if they can be how will it affect any long term running of the engine?  It has no more than about 11 psi boost right now but it seems hard to start after I shut it off and this is a new engine with plenty of compression, timing at 1.0 m/m and no leaks at the pump right now and the glow plugs and advance lever work fine.  It does this after just sitting for maby 15 min in the garage but the engine runs great with no smoke at all to amount to anything.  I was thinking about putting the N/A injectors in which I know are in good shape just to see if it made any difference.  I did take the T/D ones apart and clean them and lapped the surfaces and they do not leak externaly.  The pump settings have not been touched.  The engine only has about 1 hour on it so far but runs great in all other respects.

so you believe the injectors are leaking into the cylinders???  :shock: yea its best to get that fixed right away! getting them pop tested would be a good way of testing for that.  the N/A injectors should work okay.  vw engineers increased the breaking pressure to ensure a 'safe fuel atomization."  i think with really cold fuel, the extra breaking pressure might help atomize it better.

[Rabbit TD]

Can the 1.6 T/D injectors be switched to the 1.6 N/A injectors just for diagnosing a possible leaking injector problem and if they can be how will it affect any long term running of the engine?  It has no more than about 11 psi boost right now but it seems hard to start after I shut it off and this is a new engine with plenty of compression, timing at 1.0 m/m and no leaks at the pump right now and the glow plugs and advance lever work fine.  It does this after just sitting for maby 15 min in the garage but the engine runs great with no smoke at all to amount to anything.  I was thinking about putting the N/A injectors in which I know are in good shape just to see if it made any difference.  I did take the T/D ones apart and clean them and lapped the surfaces and they do not leak externaly.  The pump settings have not been touched.  The engine only has about 1 hour on it so far but runs great in all other respects.

so you believe the injectors are leaking into the cylinders???  :shock: yea its best to get that fixed right away! getting them pop tested would be a good way of testing for that.  the N/A injectors should work okay.  vw engineers increased the breaking pressure to ensure a 'safe fuel atomization."  i think with really cold fuel, the extra breaking pressure might help atomize it better.

I think it might be a possibility, I just thought I would stick the injectors from the other engine in to see if it makes a diference in starting as that motor starts as soon as you hit the key, doen't turn over 1 time after it's warm.  This engine is brand new with a 1 notch gasket which I checked the projection wth the new pistons installed.  These pistons were .005 shorter than the originals which allowd me to surface the block a few thousandths and I ended up with a 1 notch when it was all said and done.  This motor just seems to tke a long time to start even when it's warm.  You have to crank for at least 10 seconds straight before it fires.  I checked this morning before I started it and removed the inlet banjo and the pump was full to the top before I did anything.  I checked for voltage  at the glow plug bus and it was there and the plugs were good when I put them in.  Timing is set to 1.00 m/m same as the N/A.  I haven't done an actual compressin test yet but will tomorrow when I switch injectors but hand turning the engine feels as good as the other engine with a ratchet.  I did notice some erosion on the piston on the old pistons when I tore this motor apart which I never heard run, junk car.  I don't notice any smoke to amount to aything when it starts after a 10 second grind, I would think there would be some after that wouldn't you?  After it starts which it does on all 4 it runs fine and I can't believe how little smoke there is from this engine which doesn't have over 1 hour on it now and really pulls good for no more than 10-11 psi boost.  I don't know how they act with leaking injectors but I figured it wouldn't run near as good as it does if they leak but there was erosion at the edge of most all the pistons in the recessed area that were in it which I think is a sign of bad injectors isn't it?  The engine or at least the speedometer in the old Jetta showed 432,000 and really other than the rings worn to nothing and some erosion on the pistons the motor didn't really look to bad for that much mileage.  I took the injectors apart {1 at a time} and  cleaned them spotless, lapped the surfaces and torqued them after puttig together and torqued putting in the engine and no leaks are showing.  I'm hoping it's just old injectors as them and the pump  are the only things not rebuilt, Maby it takes a while for them to build enough pressure or something before they pop after sitting.   I will find out tomorrow :roll:

[Rabbit TD]

The lower breaking pressure will cause the timing to be overly advanced.  Use the N/A timing spec and it should be ok.

Andrew

I have the timing set to 1.0 m/m on both egines which I am going to double check tomorow on the T/D before I change the injectors which this seems to point to after my checks today showed everything else Okay other than an actual compression test but hand turning with a ratchet it fealt pretty close to my N/A on the floor beside the car which is a great little motor.  If I do switch jectors which I probably will I will do a compression check while they are out for future reference, the motor has about 1 hour on it now and runs great other than the slow start and I can't believe how clean the exhaut is mostly just a little gray when you give it some fairly heavy throttle trying to help seat the rings, which makes me think it's not getting enough fuel but I haven't touched a thing on the pump other than the throttle stop for idle speed.  Any other information or thoughts would be appreciated as always.

[Rabbit TD]

Can the 1.6 T/D injectors be switched to the 1.6 N/A injectors just for diagnosing a possible leaking injector problem and if they can be how will it affect any long term running of the engine?  It has no more than about 11 psi boost right now but it seems hard to start after I shut it off and this is a new engine with plenty of compression, timing at 1.0 m/m and no leaks at the pump right now and the glow plugs and advance lever work fine.  It does this after just sitting for maby 15 min in the garage but the engine runs great with no smoke at all to amount to anything.  I was thinking about putting the N/A injectors in which I know are in good shape just to see if it made any difference.  I did take the T/D ones apart and clean them and lapped the surfaces and they do not leak externaly.  The pump settings have not been touched.  The engine only has about 1 hour on it so far but runs great in all other respects.

so you believe the injectors are leaking into the cylinders???  :shock: yea its best to get that fixed right away! getting them pop tested would be a good way of testing for that.  the N/A injectors should work okay.  vw engineers increased the breaking pressure to ensure a 'safe fuel atomization."  i think with really cold fuel, the extra breaking pressure might help atomize it better.

I wonder how long it takes for a leaking injector to start eroding the pistons and glow plugs and such.  But I still can't imagine why it wouldn't have a lot of smoke on start up after cranking so long and also run as good as it does clean as can be compared to my N/A and which runs perfect , and starts just bumping the starter unless it's cold.  I guess I'll find somthing tomorrow when I swap some things and do the compresion test. I didn't bother doing one putting it together snce It wouldn't be a fair test with brand new rings anyway.  It does feel pretty much like the N/A turning it with a ratchet right now though.

[burn_your_money]

If it was my car I would do a voltage drop test on the wires from the battery to the starter. Does the car fire up fine when it's cold?