Rebuilt Injector Pump + New injectors = Fail --Please Help--

[CorradoZilla]

Hi,

This will be long, but I am trying to be as complete as possible. In advance thanks for reading, any help is greatly appreciated.

I'm running a 1.9 TD from a 93 Passat (Eco) with an injector pump from a 94 Golf so I have an LDA and am using a CHD tranny in an 86 Scirocco with a 2.25" exhaust straight pipe back, new air and fuel filter, compression tested before rebuilding the pump and the turbo is/was hitting .6 bar (8.5 psi +/-). Have been running this set up for many years now, and after doing so I have always wondered why people would want the much slower TDI rather than a TD. My pump finally started leaking and also I finally couldn't stand to listen the the monkey's with hammers under my hood any longer (nailing if you want to get technical about it). So I dropped my pump off at my local Bosch service center (just now reading about Giles work, damn 20/20 hindsight), and ordered rebuilt Bosch injectors. I went the stock route because at this time I was happy with current performance and economy.

To start, the injectors on my car being the first 1.9 were the small single spring injectors, and the ones I ended up with were the larger body 2 spring injectors. I tried finding any information I could on compatibility and found little, however what I did find said they are hot swappable, they will help quiet and smooth the engine at idle so I went with it. (old had 155 bar vs new at 150)

I got my pump back (with a slew of new and used parts installed into it) and installed my new injectors and pump. I performed the timing procedure to a T (using the cam lock and dual feeler gauges etc) and checked it twice to verify the correct setting (.80 mm book and mine is .81mm, idle speed is set for 900, high idle 1050 and the electronic advance is always on). Attached the cold start at this point and adjusted so it hit it's 4 stops. Primed and bled the system and let warm up. Now the problems:

Right off the bat, I had these probs and also a further leak, so I had to take it off the car again and take it in. They fixed the leak and said the pump checked out, but the issues remained.

First off the idle is crazy rough. Now I did just put in brand new motor mounts, which will definitely account for harshness through the cabin, but this thing shakes the entire car like a leaf. It smooths out somewhere between 1000-1100 rpm (I don't have a tach in the car, but a reflective dot on the flywheel and laser tach for static adjustments in the driveway). No amount of bleeding will change this roughness.

Secondly the car is wayy down on power. From idle there is no pick up, until the turbo kicks in, it has a very dramatic lag and spike (I'm used to pretty quick and uniform acceleration from before). The turbo is a T2 .48 so it used to be a very lively boost right from the get go but would definitely flatten out in certain areas.

As for the top end, 5th is useless. Now before you say 5th is an overdrive, before the rebuild I would rarely downshift on the highway, just put the foot down and go. It would pull very steady from 110-180 kmh where it would run out of juice. (*Disclaimer* I do not recommend anyone perform indicated driving on any stretch of highway for testing purposes. This was a figure I had arrived at a few years ago before smartening up). Now on the highways 5th is painfully slow from 110-120kmh and with open road barely wants to make 140kmh. I find myself cruising in an using 4th constantly as it mimics the performance I had in 5th. Before under full throttle there would be a little puff of black smoke until the turbo caught up where now the only time I ever see black smoke it on cold start up leaving me to believe the pump may have had some adjustments before.

And as for cold starting, I used to start without fail down to -25 Celsius. It was quite remarkable, however now even around -10 it will start and die, then I'll glow again, where it may start and die or miss for a few seconds until all cylinders catch.

And the icing in the cake is my fuel economy has gone from and average of 5.8 L/100km (41mpg) to about 7 L/100km (35 mpg). I know it's winter, but i have been driving this car for years and my figures usually only hit the mid 6's on the worst of weeks every since I've been tracking economy.

With all of that being said.....Does anyone have any suggestions of what is up? I know I can tune it for more power, but I would like to get it running well baseline, first then tune. I will concede maybe the pump was tuned before me, but I did pull it off a bone stock 4 door golf. Also the re builder changed the cam plate. Is it possible he used cam plate of a VE pump, but not one for a 1.9 so the profile is different?

Thank you so much for reading. Again any input is greatly appreciated.

Adrian

[coke]

.81mm? Timing spec for TD is 1.05mm I believe.

[Vincent Waldon]

My very first thought is that your timing, although technically with-in spec, is very retarded from a performance/power/economy perspective... and lucky it will be an easy thing to try!

The factory AAZ timing is particularly slanted towards the emissions side of the fence.. on your engine 1.0-1.05mm likely to be a much much happier number for you.

5th gear should be completely usable, with good passing torque for the highway... it just really sounds like you're so down on power at the moment the car just can't twist hard enough.

Try 1.00 or there-abouts and see if things are noticeably better.... I don't see anything obviously wrong otherwise with your setup.

One last thing... is your turbo configured to be full time, or defeated most of the time as per the Passat eco config?  To confirm, look for a second vacuum hose coming out of the turbo's wastegate that goes to a small solenoid valve and then on to the vacuum pump hose.  If so, you can easily convert the turbo to full time which will also improve drivability... vent the hose going to the wastegate to atmosphere in a way that water won't soak in, and then cap the other end of the solenoid and unplug it.

[Vincent Waldon]

.81mm? Timing spec for TD is 1.05mm I believe.

Eco Passats have a really really conservative spec.

[coke]

Didn't know they even made an ECO passat Vince, till I saw this writeup. I still can't believe the spec was .80mm, give or take.  Judging by his rough starts and low power, first thing I thought was retarded timing.

[Vincent Waldon]

I agree with your instincts.   

Yeah, the early 1990's were wacky from an emissions perspective.... early Canadian Passats got the tiny pump (8mm), part time tiny K03 turbo, very retarded timing, and a catalytic converter.

[CorradoZilla]

Thanks for the input.

.80 was the spec for my motor according to the FSM. My first pump was an LDAless pump with no idle increase or anything. just bare pump. The new pump has the vacuum idle increase and then the useless idle advance solenoid. I have been doing some reading about setting the timing to .95 +/- .5 for a much more fun drive. This will be my first attempt at picking up the pump, since is it is now supposed to be at stock.

The turbo is a T2 with only a single vacuum line from the compressor side to the waste gate. I'm looking at getting a proper boost controller to reduce the lag.

Questions: My pump head and cam plate were replaced with ones from a parts pump they had at the re builder. Should I be inquiring about what engine they were from, what specs they are? As I understand it, if for some reason they used say a 1.6 plate, although I could set my timing, my overall fueling would be down. Also I guess it would be interesting to know whether I have the tiny 8mm or the reg 9mm found in most 1.9s.

Also has there been any known issues with genuine Bosch rebuilt injectors?

Thanks again for the help.

[CorradoZilla]

As has been said, advance the timing.  If it still behaves poorly, swap your old injectors back in.  The injection pump plunger is different for the dual stage injectors (has an extra channel and a couple extra cross-drill holes).  The injectors should match the plunger.

That's unfortunate for me. I had a feeling about that and I had actually kept my injectors for about 2 mo after buying the rebuilt injectors, however after spending $1500 on parts, I had to cave and claim the core charge for my injectors. It was just to big a hit at the moment to hang onto any longer 

[Vincent Waldon]

My vote... try the obvious and easy (timing) before sweating the more sublime and expensive (matching pump plunger to injectors).

And don't be scared to try past 0.95... you can't really hurt your engine with more advance than optimal.. it just gets noisy and harder to start.

My AAZ with 150 bar injectors ran the best at 1.05... *with* a Giles pump that already has tons of dynamic advance already. 

[Vincent Waldon]

Ah Andrew...are you admitting to having your head in the clouds??!! 

<duck>   

[smutts]

you can't really hurt your engine with more advance than optimal.. it just gets noisy and harder to start.

All my injector nozzles went a nice blue temper colour from being overheated by my messing around with my tranfer pressures, (too much advance at higher rpm). this probably was not good for their hardness either.
They look very pretty though!
Moral of the story............Don't use Hagars transfer pressures, they are too fierce for the SB engine.

[CorradoZilla]

Some headway has been made! It's been a long time coming but I finally had the time to play.

I timed the motor to .95 drove it for a day to see how it felt then properly set up the idle, high idle, residual and max rpm settings. The low to mid range much closer to the way it was before. There a reasonable amount of get up and go off the line and around town. Still feels like it's lacking a bit, but the butt dyno isn't known to be that accurate. However it is still lacking greatly in the upper gear acceleration. As I've noted before, there is no longer a puff of black smoke under full throttle acceleration, so I'm thinking my boost pin may be installed incorrectly, and/or my max fuel screw could use some adjusting. I will drive it around this way until my pyrometer comes in and then play some more.

Another win is that the cold starting actually seems to be better and my idle is smoother. So all in all a sucess.

Thanks for the help, I'm going to keep tuning until it's back to tearing up the highway, or it consumes more fuel, whichever comes first.

Thanks

[R.O.R-2.0]

Some headway has been made! It's been a long time coming but I finally had the time to play.

I timed the motor to .95 drove it for a day to see how it felt then properly set up the idle, high idle, residual and max rpm settings. The low to mid range much closer to the way it was before. There a reasonable amount of get up and go off the line and around town. Still feels like it's lacking a bit, but the butt dyno isn't known to be that accurate. However it is still lacking greatly in the upper gear acceleration. As I've noted before, there is no longer a puff of black smoke under full throttle acceleration, so I'm thinking my boost pin may be installed incorrectly, and/or my max fuel screw could use some adjusting. I will drive it around this way until my pyrometer comes in and then play some more.

Another win is that the cold starting actually seems to be better and my idle is smoother. So all in all a sucess.

Thanks for the help, I'm going to keep tuning until it's back to tearing up the highway, or it consumes more fuel, whichever comes first.

Thanks

thats because its timed right.. (well, closer to right)

[CorradoZilla]

Actually my cold starting is amazing! For the last few days I haven't needed to use the glow plugs for temps hovering around 0 C. I have never been able to start my car without the glow plugs, even in the summer months.

Question for Vincent or any cold weather guys. Vincent you said that you have your pump timing up to 1.05 (I'm currently at .95) and you said more advance will cause hard starting. What do people find about running pump timing at 1.0 or higher in cold winter temps. And by cold I mean -20 C (-4 F) or colder.

Thanks for the input.

PS R.O.R What do you mean closer to right? Are you suggesting a move to 1 and above?

[Vincent Waldon]

you said more advance will cause hard starting. What do people find about running pump timing at 1.0 or higher in cold winter temps. And by cold I mean -20 C (-4 F) or colder.

I'm in a climate that regularly sees -25C and with my particular pump and engine 1.05 is right on the edge of too much advance for optimal cold starting.  I know this because adding even more advance (by pulling out the cold start handle) makes the car bog down and *not* start.  I therefore start the car with the cold start handle in, and then yank it out as soon as the engine catches.

I got to 1.05 by experimenting... at 1.00 I could pull the cold start handle and not impact starting speeds whereas at about 1.08 the engine started very hard in cold weather.  With too much advance the overly-early fuel ignition at starter RPMs pushes against the rising pistons at an early crank angle and slows down the engine.

I say "my particular pump and engine" because the dial indicator measurement can't take pump wear etc into account, so the actual optimum value is going to vary a bit from car to car.

In other words, YMMV!