Author Topic: 1991 Jetta 1.6 NA questions  (Read 3509 times)

May 26, 2010, 02:32:23 pm

forced2bcheap

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1991 Jetta 1.6 NA questions
« on: May 26, 2010, 02:32:23 pm »
Hi,

I've got a 1991 Jetta with a 1986 Golf engine in it, that has about 320,000 miles on it (80k on the engine, if I can believe the PO).  I've had it for a couple of years, but I still have more questions than answers.  This is my first diesel and I've been lurking here and at vwvortex for a while.  Poking around has given me a lot of good information, but figured I ought to just sign up and ask you guys straight out.

It's got a greasecar kit installed in it, which makes the hoses under the hood look like a plumber's nightmare.  I ran on wvo for a little while, but other non-veg parts started failing so often I lost touch with my wvo sources.  For now, I just want to get it reliable enough to be a good diesel daily driver.

I should say that the problems I have had are not really enough to keep it off of the road, it's just that I don't get a lot of time to tinker, so a bad rear wheel bearing had the thing sitting in the driveway for a month instead of an afternoon.

1. Right now, the downpipe has rotted and broken in two.  I've rigged a really awful temporary patch, but in my dreams I'd like to do something like what clbanman did here:

http://www.vwdiesel.net/forum/index.php?topic=20427.0

Trouble is, I've never welded anything before.  I've thought about buying something like a 2.25" system for a 91 gasser from germanautoparts.com - which looks like it would probably fit, but I'd still be stuck for a downpipe.  Does anyone know where I could get a "storebought" 2.25" downpipe?  Or is the whole thing a bad idea?

2. I'd like to run a diesel purge through the system.  Like I said, the hoses are a nightmare so I've been afraid of touching them and starting a leak because they're also old-looking and may be about to fail.  I've bought some new hose and some clear hose from mcmaster-carr and I'm working up the courage to tear into it.  

The reason for the purge is that the car runs fine, but misses at high rev.  I tried doing the next best thing to a diesel purge by filling a new fuel filter with seafoam and running that through the engine.  Like I said, at low-to-medium rev (no tach - just guessing by sound) everything runs smoothly.  When you step on it, you hear a miss followed by some black smoke belching out of the tailpipe.  Does that sound like a purge would help, or do I need a new Giles pump?   ;D

3. Black smoke also happens on hills and on-ramps - probably because I'm standing on the accelerator begging it to go faster.  Someone suggested using Mann filters, which seemed to pep it up a little bit.  The PO has a shop vac hose sucking air from the inner fender, so I was wondering if there was a better way than that to get more air - and if that would help.  Should I ditch the Mann for a K&N?  I haven't measured the I.D. of the shop vac hose, but it fits nicely into the air filter housing.  I've been pondering cutting a bigger hole in the housing and piecing together a Spectre system.
  
4. I'd like to replace the injectors, but they look so rusty that I'm afraid I'll break them off.  Someone told me that impact wrenches actually snap fewer bolts because they give a little extra vibration that helps break things loose.  It seems crazy to take an impact gun to something like an injector though.

I saw a post where someone had gingerly tightened and loosened their injectors by hand while marinating them in some kind of penetrating oil, eventually getting them out.  That seems more reasonable, but I do have a history of snapping bolts so what do I know?

Any help would be greatly appreciated.

Thanks,
-Bill


Reply #1May 26, 2010, 07:57:34 pm

8v-of-fury

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Re: 1991 Jetta 1.6 NA questions
« Reply #1 on: May 26, 2010, 07:57:34 pm »
Clbanman has the right idea going on. There is no need for a different type of downpipe-to-exhaust connector, that one works just fine. It will not be difficult to fab something up to work I shouldn't think.

Diesel purge will be good even if it doesn't fix your weird higher rev miss. It can never hurt to purge it. Do you know by any chance what the injector pump is timed at?

Black smoke will happen when unburnt diesel is making its way through the combustion process and out your tailpipe, like when you mash your go-go pedal on a hill and the engine cannot bring its revs up to deal with the amount of fuel you want it to burn. A larger intake will help a fair amount with the smoke, as it will allow the engine to suck in the necessary air in order to burn the fuel. A larger exhaust will also help with this. There have been a ton of speculations floating around, I don't find K&N does anymore than a good quality paper filter... I have a Mann filter and stand by it. Plus I'm not paying $50 for the filter and $20 for the kit to "Recharge" it... I'm "forced2bcheap" as well lol.

A good dose of penetrating fluid on your injectors in a couple of hour intervals and then a turn out, turn in, two turns out, turn in procedure of going back and forth has been said to reduce the amount of breakage, but anything can happen. Just make sure you push your cheater/breaker bar towards the head as to not put all that force on the tiny little boss of the injector at the bottom.. It will crack..

Got any pictures of your ride? :)

Good luck with this.

Reply #2May 27, 2010, 09:49:28 am

morgoon

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Re: 1991 Jetta 1.6 NA questions
« Reply #2 on: May 27, 2010, 09:49:28 am »

A good dose of penetrating fluid on your injectors in a couple of hour intervals and then a turn out, turn in, two turns out, turn in procedure of going back and forth has been said to reduce the amount of breakage, but anything can happen. Just make sure you push your cheater/breaker bar towards the head as to not put all that force on the tiny little boss of the injector at the bottom.. It will crack..

Got any pictures of your ride? :)

Good luck with this.

8v-of-fury is always right on, and a no BS source of knowledge..I haved notice in my short time here…

The only thing I would like to add in my very limited brand new experience is when I took the injectors out of my 1.6 core motor…I had to be very patient…work at a pace that won’t let you get too “rammy”, cause that is my thing at times.

When I got my injectors out of the head it was with great effort…I finally had to goose it  with an extension on my cheater bar :o for the last one (pushing just as 8v said) I never got to the one turn/ two turn stage till the injector was dang near out of the hole…I started with a fractional forward..(by feel more than sight it was that hard to see at first) then back, then forward and repeat with penatrant often.

Progress was slow, and hard to really measure at first, I did make up a T shaped cheater bar as suggested by the good people of this forum to even the torque applied…

I made mine out of round pipe welded to heavy fence T bar, so it would slide over the handle of my breaker bar

I bought a 12 point 1 1/16  deep socket to go over the injectors, Snap on as I understand it has a special one..I have to hog out the shoulder of my socket to clear the nipples on the injector…3 came out without damage..the 4th one was a REAL>>>>>>>>>> Bugger and I did bend them inward a bit

Here is my thread on the experience…

http://www.vwdiesel.net/forum/index.php?topic=25521.0

buy the best penatrant you can afford..

More patience, this forum and having to just jump in and try it, were the most important things for me….Good luck!!!!

Reply #3May 27, 2010, 12:12:59 pm

forced2bcheap

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Re: 1991 Jetta 1.6 NA questions
« Reply #3 on: May 27, 2010, 12:12:59 pm »

>Clbanman has the right idea going on. There is no need for a different type of downpipe-to-exhaust connector, that one works just fine. It will not be difficult to fab something up to work I shouldn't think.

I would reuse the broken connector and just cut out a 2" hole at the bottom of the bowl.  But then I have to teach myself how to weld!   :o   Also, I would have to locate a welder to rent, or buy a harbor freight cheapie:

http://www.harborfreight.com/welding/mig-flux-welders/90-amp-flux-wire-welder-98871.html


>Diesel purge will be good even if it doesn't fix your weird higher rev miss. It can never hurt to purge it. Do you know by any chance what the injector pump is timed at?

No, I haven't the slightest idea.  Is that where you stick a dial gauge into the front of the injection pump and turn the engine over by hand?  I'm not that guy yet.   ;)

>Black smoke will happen when unburnt diesel is making its way through the combustion process and out your tailpipe, like when you mash your go-go pedal on a hill and the engine cannot bring its revs up to deal with the amount of fuel you want it to burn. A larger intake will help a fair amount with the smoke, as it will allow the engine to suck in the necessary air in order to burn the fuel. A larger exhaust will also help with this. There have been a ton of speculations floating around, I don't find K&N does anymore than a good quality paper filter... I have a Mann filter and stand by it. Plus I'm not paying $50 for the filter and $20 for the kit to "Recharge" it... I'm "forced2bcheap" as well lol.

Here are a couple of pictures of the shop vac cold air intake.  It fits so nicely, I want to believe its stock.  What do people use to make a bigger hole - just a rasp?, or is there some grinder that wouldn't get all gummed up with melted plastic?:





>A good dose of penetrating fluid on your injectors in a couple of hour intervals and then a turn out, turn in, two turns out, turn in procedure of going back and forth has been said to reduce the amount of breakage, but anything can happen. Just make sure you push your cheater/breaker bar towards the head as to not put all that force on the tiny little boss of the injector at the bottom.. It will crack..

I use Aerokroil because I heard it was the best from a few people.  Now I see some people are using something called Plusgas, but it looks like a UK-only product.  I also found a test that some magazine did where they decided that a 50/50 mix of power steering fluid and acetone worked best.  I haven't tried that one yet...

>Got any pictures of your ride? :)

Just a couple more of the engine.  I'll post some exterior shots as soon as I can.  She's not pretty, but I'm not done yet either!   :)

Here's a picture of what are supposed to be clear tubes.  Like I said, they may start leaking when I try to replace them:



Here are the injectors:




Do these stains mean my IP is leaking, or is that just normal on an older engine?:



Lastly, is this how the diesel filter is supposed to be set up?  There's a 5/16" hose going in from the fuel tank and one coming out and going (eventually) to the IP, but this other small hose goes in a loop.  Is that something creative the previous owners did, or is that really supposed to just loop to nowhere like that?:



>Good luck with this.

Thanks, I'll need it.

Reply #4May 27, 2010, 12:36:09 pm

forced2bcheap

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Re: 1991 Jetta 1.6 NA questions
« Reply #4 on: May 27, 2010, 12:36:09 pm »

Here is my thread on the experience…

http://www.vwdiesel.net/forum/index.php?topic=25521.0



This is the thread I was referring to in my original post.    ;D

Patience always pays, but it's hard to remember that in the heat of battle.

Thanks for the replies guys!
-Bill

Reply #5May 27, 2010, 01:00:33 pm

vanbcguy

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Re: 1991 Jetta 1.6 NA questions
« Reply #5 on: May 27, 2010, 01:00:33 pm »
The 'loop' in the fuel line is eliminating the circulation valve on the filter. 

From the factory, the return line from the pump would have gone in one end of that white valve and then the return to the tank would have come from the other.  The idea was that when the engine is cold that white valve would be open and would circulate fuel back directly to the fuel filter, hopefully warming it up.  Maybe it's the modern fuel but it seems to be unnecessary these days.  It's a complete PITA if you have any air in your system - it'll just keep circulating air bubbles back through the filter and in to the pump again which is more than likely why it's been bypassed.

Kind of a weird way to eliminate it, but you're probably better off without it.  There are some filters out there that don't have the valve at all, when you replace your filter you might want to find one of those.  Or better still get a nice spin-on filter!
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #6May 27, 2010, 08:01:06 pm

8v-of-fury

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Re: 1991 Jetta 1.6 NA questions
« Reply #6 on: May 27, 2010, 08:01:06 pm »
Your intake system is, other than the tube, stock pretty much. The stock Mk2 N/a air tube went to the passenger fender.

Do you have any room up beside the radiator on the mk2? I can't recall as I rarely frequent them unless my gf's breaks down. lol What I plan to do on my mk1 is a sort of ram air ducting. It will be that whole area beside the rad in a rectangle intake, and it will slope down to the 2.25" (dunno about pipe sizing yet) pipe and that will aid in the "ram air" and increase velocity as it tries to squeeze its way down the small tube from a large intake. It should work out nicely :) Making a bigger hole in the air box? I find a Skill Saw cuts the plastic nicely. What will you do once you get a bigger opening? Graft on a new tube? its quite easy to graft plastic with some steady hands behind a blow torch :P

Your car looks to be in good condition. Known time of last timing belt change?

Reply #7May 28, 2010, 08:08:16 pm

forced2bcheap

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Re: 1991 Jetta 1.6 NA questions
« Reply #7 on: May 28, 2010, 08:08:16 pm »
The 'loop' in the fuel line is eliminating the circulation valve on the filter. 

From the factory, the return line from the pump would have gone in one end of that white valve and then the return to the tank would have come from the other.  The idea was that when the engine is cold that white valve would be open and would circulate fuel back directly to the fuel filter, hopefully warming it up.  Maybe it's the modern fuel but it seems to be unnecessary these days.  It's a complete PITA if you have any air in your system - it'll just keep circulating air bubbles back through the filter and in to the pump again which is more than likely why it's been bypassed.

Kind of a weird way to eliminate it, but you're probably better off without it.  There are some filters out there that don't have the valve at all, when you replace your filter you might want to find one of those.  Or better still get a nice spin-on filter!


Thanks for finally clearing that up!  I've been wondering about that for two years.   ::)

Do you have a favorite spin-on adapter?  Does that mean that I would be using oil filters instead of fuel filters?  I did a couple of searches but they all seem to come back with something like "oil filter bypass adapter".  Sorry if these questions sound clueless, but in this case I am.   ;D

Reply #8May 28, 2010, 08:54:43 pm

forced2bcheap

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Re: 1991 Jetta 1.6 NA questions
« Reply #8 on: May 28, 2010, 08:54:43 pm »
>Do you have any room up beside the radiator on the mk2?  

I'll have to poke around a little.  The greasecar plumbing is right next to the fender mount and may interfere.  I was wondering if it might be possible to invert the air filter housing and route the hose on the driver's side.  I'll have to see if I can get past the radiator better on one side or the other.

>I can't recall as I rarely frequent them unless my gf's breaks down. lol What I plan to do on my mk1 is a sort of ram air ducting. It will be that whole area beside the rad in a rectangle intake, and it will slope down to the 2.25" (dunno about pipe sizing yet) pipe and that will aid in the "ram air" and increase velocity as it tries to squeeze its way down the small tube from a large intake. It should work out nicely :)

Ram air?  I like the sound of that.  So, you're saying that I might not have to carve up the air filter housing if I get the angle right so that air gets shoved in there better?

>Making a bigger hole in the air box? I find a Skill Saw cuts the plastic nicely. What will you do once you get a bigger opening? Graft on a new tube? its quite easy to graft plastic with some steady hands behind a blow torch :P

Yeah, it sounds like it could get pretty ugly.   :)   I was trying to cut a broken sway bar end link off of my Explorer and it had a plastic/rubber cover that melted and coated my grinding stone with black goo.  I ended up using bolt cutters.  

>Your car looks to be in good condition. Known time of last timing belt change?

If I can believe the PO, he changed it just before he sold it to me, at 61K on the engine.

That brings up another question.  Hypothetically, if the PO had rolled back the odometer to match the mileage on the engine rather than on the vehicle, how could someone "correct" that so that *they* wouldn't get blamed for it when they sold the car to the next person?  Other than just driving it until the odometer reads 320,000 could someone attach the speedometer cable to a drill and roll the mileage back up to where it belongs?  Hypothetically?

Here are some more photos.  It's up on ramps because my downpipe hack job needs more tweaking:










Oh, another thing.  If you look at the pictures, the paint on the passenger's side looks okay, but the rest of the car must have been parked facing the sun or something because it really needs help.  I found one of your old posts about something called trem-clad but it looks like the pictures are gone:

http://www.vwdiesel.net/forum/index.php?topic=21128.0

I guess trem-clad is just Rustoleum down here in Taxachusetts?  So, the short version is prep the car then get a smooth roller and go to town?

Thanks,
-Bill
« Last Edit: May 28, 2010, 09:04:16 pm by forced2bcheap »

Reply #9May 28, 2010, 10:01:15 pm

Baron VonZeppelin

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Re: 1991 Jetta 1.6 NA questions
« Reply #9 on: May 28, 2010, 10:01:15 pm »
I can chip in a few things to educate you on your car some too.

Injection Pump:

Those wet stains do usually indicate a leak. You can hit it with carb cleaner and let it dry good - then see if they come back. Yours looks to be leaking where the pump head mates to the pump housing - that "can" cause various performance issues.
But it may just be fuel return hose leaking and falling down there.
After you get it dry, you can inspect better.

New fuel hoses and clamps are good insurance.
If you aren't using the Grease stuff, I wouldn't fool with those - except to remove them.

That also is not the original 89-92 style Inj Pump. It is from an older model. But you just mentioned something about engine being replaced - i think. so anyway ...

Air Intake Tube:

You have several pieces missing from the original set-up. I wouldn't worry about it all though - what you have seems as good or better than what most are using (Nothing).

There was a plastic tube that mounted to the airbox that was L shaped. An adapter collar mounted to that - then a huge coiled hose covered in foam rubber type insulation. Then another adapter collar - that snapped into the plastic receptacle on the passenger inner fender. You can still buy all that stuff - but would be around $200 for all of it - New.

I wouldn't bother with a K&N filter unless you run out of other things to spend money on.

If you have good tight fit on each end of that hose - you already have a good source of force fed cool air when in motion, and cooler air at stand still. As opposed to others who just draw hot underhood air. 

Fuel Filter:

An 85-88 style filter will mount right in the factory holder you already have. They do NOT have the extra nipples for the return lines. Much less hassle than the 89-92 style. And usually a few bucks cheaper too.

A 'spin-on' is like what came on older Mk1's (84-older).
You can buy them used (filter mount/pedestal) pretty easy. And makes it easy to get a filter application at a parts store. Just say 82 Rabbit diesel (example). Filter is not same as an oil filter. And usually have a drain on bottom.

About like the one in your picture that goes with the grease system.

Injectors:

Yours look typical for Northern exposure.
A week in advance of when you want to remove them - spray them with PB Blaster 2-3 times a day. I wouldn't try an impact gun until after i had a go at them with 1/2" drive hand tools.

1 1/16" deep well, 1/2" drive, 6 point socket at Sears is about $10-11 and fits great and doesn't hang up on the injector nipples up top.

Always follow the Golden Rules of Injector Removal !

Odometer:

If you could get the past inspection records and chart mileage to find where it went oddball at - you could use that as a benchmark to reset to. Or maybe a Carfax report.

You "could" remove cluster from dash and mount a power drill in a vise - run a piece of junkyard speedo cable from that to cluster - and let it rip for however many hours it takes. You "could" also replace the cluster with a similar miled unit, or adjust mileage the way the rollbackers used to. You would be a rollerupper though.

Reply #10June 11, 2010, 09:56:49 pm

forced2bcheap

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Re: 1991 Jetta 1.6 NA questions
« Reply #10 on: June 11, 2010, 09:56:49 pm »
>That also is not the original 89-92 style Inj Pump. It is from an older model. But you just mentioned something about engine being replaced - i think. so anyway ...

It's supposed to be an engine from an 86 Golf, shipped here from Japan, of all places.

From looking at Prothe's site, it looks like an 86-91 except the front looks like it is missing a metal plate?  I hope it doesn't bite me if I try to send it to someone like Giles as a core.  I'm pretty far from that right now anyway.  I just blew $618 getting my Explorer inspected (I let the inspection/repair shop talk me into doing work I should have done myself), and I got pulled over in my Jetta for an expired registration.   :'(  Pretty bad week, car-wise.  My bad on the registration - I got behind on my mail.

Oh well, it's only money, tomorrow's a new day, we learn more from failures than successes, (insert your favorite rationalizing optimistic quote here)...

Reply #11June 11, 2010, 10:59:05 pm

Baron VonZeppelin

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Re: 1991 Jetta 1.6 NA questions
« Reply #11 on: June 11, 2010, 10:59:05 pm »
89-92 had the altitude adjustment aneroid devices.
The inj pumps had the aneroid on top (flying saucer) that makes it look just like a TurboDiesel inj pump. And a little vacuum can gizmo over on passenger fender apron.

But its nothing you can't live without by any means.
And about everyone defeats its operation anyway, unless they live in the high hills.

Prothe has his own justice on some things.

Sorry to hear about all the inspection carnages.
Some of that stuff can get rough.