My 91 GTI 8 valve to B4 1Z TDI swap

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
A flashing glowplug light should register a code of some sort. Make certain your brake lights are working and also make certain that the cruise control works properly in vagcom. Reference this: http://forums.tdiclub.com/showthread.php?t=253443
Yeah I am almost certain that it is related to the column switches..the brake lights work fine, the pedal switches are all out of the passat donor...almost all the original switches are acting funny due to resistance from tarnish on the contacts..the turn signals are intermittent as well as the high beam/low beam.. I have rebuilt these switches before in my coupe and friends cars..it is a PITA but I think still better than the cheapo aftermarket replacement ones..The GTI sat for literally ten years so I am not surprised by the issues that are surfacing.
 

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
Took the GTI for its first long test ride last night. Drove to Hyannis to meet up with the local VW guys, had no problem keeping up with my buddies 16V GLI! I am so excited about the fitment of the mk3 cluster in the mk2 dash, I will have to upload some pictures of how I modded the bezel. It literally looks like it was meant to be there! I occasionally get a flashing glow plug light that comes on while driving or even after it has been idling for a while. Goes out on its own after I slow down. Brake light/clutch switch issue as G60ING advised I am assuming.. But what is more of a concern to me is the intermittent lack of power I am experiencing. It will seem to get it back after a little driving or especially after stopping and restarting. Seems like a whole different beast after restarting actually. I am definitely pleased with the performance...when it is performing! This lack of power situation doesn't seem to correlate to the glow plug light flashing, and it doesn't illuminate the MIL.
:confused: The side exit exhaust is apparently quite loud outside the car but inside it is way quieter than my Coupe (which has a Bosal header/eurosport cat back)
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
MD
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
What does vagcom say?
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
MD
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
odd

boost gauge readings?
 

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
No boost gauge as of yet, I will hook up the shop vacuum/pressure gauge this evening and see whats going on. I drove it again this afternoon and its peppy as hell...One thing I haven't done yet is fine tune the pump timing via vag-com, and I still have to RR the fuel filter which I am going to after I run through this half a tank of old(er) fuel...
 

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
The power loss situation correlates to lower boost pressure..I took a ride last night with my Mac Task master scanner hooked up reading live data...MAP pressure went up to 228 KPa under full throttle when everything seemed ok, may have even momentarily gone higher...after it seems to lose power, the highest reading I get is 183 KPa..this tool doesn't have MAP pressure readings in psi, only inches of mercury and kilo/pasquales...No check engine light and no codes registered. It wont even take full throttle when it is in the situation either. Any ideas? faulty N75 would register a code right? Is my car going into limp mode without registering a fault? Any help most appreciated!
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
MD
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
Sounds like a boost deviation issue which could be a number of things. I think I'd be more concerned about the ecu not registering the code. See if you can get a new ECU or maybe post up in the mk3 forum with this problem.
 

cumminsfromthecold

Veteran Member
Joined
Oct 27, 2006
Location
HumCo
TDI
'84 Toyota 1Z 4WD x-cab
GTiTDi, the problem you're describing is the same one my boss is experiencing with his '98 AHU Jetta. Haven't yet hooked up my VAGCOM, but when I do, I will let you know what, if anything, it finds.

Dang, I am straight piping my truck to the rear passenger's side wheel with 2.75" steel and was hoping it wouldn't be that loud. Oh well... :rolleyes: maybe a little muffler on down the road.

Show that thing off a little. You should be proud!
 

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
I changed all the vacuum lines this afternoon, took off the N75 valve, reads 27 ohms which seems like normal, clicks when energized..but..it had oil residues in it, so I sprayed some cleaning solvent through it, blew it out, and noticed the click sound changed when I energized it..I shook it and noticed it may a click sound, which only happened once. sprayed some more solvent through it, then some penetrating oil, blew it out and shook some more...now it rattles more consistently when I shake it, but occasionally seems to stick...The limp mode seems to correlate to a boost spike so I am thinking I may have a sticky N75 valve...I read a post about someone disassembling one, I have a buddy with a spare so that is what I am going to do next.
 

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
Took the GTI to Dubs in the Sand yesterday, had a great time and got a lot of good comments! Also on the way I figured out my flashing glow light that would go out after tapping the brake pedal..the blue switch plunger needed to be adjusted! after that voila, no glow light...and functioning Cruise Control! man what a easy way to rack up the kilometers! (my cluster is Canadian) Everyone turns there head when I rev it up, the side exit is definitely a riot! hope it passes inspection! Also on Saturday my friend Burpod brought me a new N75 valve and Thermo-T from ID parts. No more air in my fuel line!
Mike from ID if you see this, pm me dude! I got a **** load of B4 stuff that's gonna get tossed!
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
MD
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
That it, I'm getting the red I badges...just ordered

Looks good
 

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
That it, I'm getting the red I badges...just ordered

Looks good
Thanks man! The Diesel bug has definitely gone beyond biting me, I think next up is selling all my 16V stuff to save up for modding the GTI. I was planning on building an ABF but now it seems silly. Anyone want 16V stuff?:D
 

burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
i love your car :D i want to get my rabbit swap going so bad... lol
 

cumminsfromthecold

Veteran Member
Joined
Oct 27, 2006
Location
HumCo
TDI
'84 Toyota 1Z 4WD x-cab
GTiTDi,

Another speedy swap and nice lookin'! Did you run 3" or 2.75" straight? Loud or excessively loud?

Thanks for posting the N75 info/solution - my boss will like that I can fix his similar problem (and I will like billing him for it) - kidding....:)
 

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
GTiTDi,

Another speedy swap and nice lookin'! Did you run 3" or 2.75" straight? Loud or excessively loud?

Thanks for posting the N75 info/solution - my boss will like that I can fix his similar problem (and I will like billing him for it) - kidding....:)
It's driving but far from done! It is a 2.25" exhaust, and it isn't too loud when off the throttle, but definitely loud when on it..the best part is when it returns to idle and the turbo slows down, sounds so cool!

As far as posting the solution to the N75 failure, that is just my way of trying to make this as concise and helpful as possible. Nothing annoys me more than reading through a whole thread to find out there isn't any useful solution at the end...
 

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
My GTI passed Massachusetts State Inspection today no problem, guys at the Inspection station had a good chuckle after hearing the mini-mack..a side exit with no muffler and still quiet enough!!!

Then I proceeded to Loud Fuel where I filled my tank with 50% B100 and 50% dino diesel, since my LOW FUEL! light was on! still had 4.5 gallons though!? Better than running it too low though I suppose.

After work I installed a Gates alternator decoupler pulley, and regreased the tensioner shaft. No more squeak at startup plus peace of mind.

Can't get enough of my GTI TDI! gotta love low end torque! I can't wait to see how she pulls after nozzles and a tune!!!
 

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
Loaded up the GTI and drove to Wolfeboro New Hampshire over Memorial Day weekend with my gf, had a wonderful trouble free trip! Used the Cruise Control as long as I wasn't ripping it past traffic and generally staying in the boost! Still barely used any fuel! 865 kilometers/537.8 miles on less than a tank of fuel (about 12 gal), and that wasn't even trying (speeds were often in the triple digits :)). Tore it up down some back roads, and Rallied it up on some dirt ones as well. Big modern advantage to ripping unfamiliar dirt roads...GPS!!
This was also while running a B100/dino blend, which I am told may have been better off with out the b100. Roughly 44.8 mpgs!!!

Let my dad drive the GTI. Now he wants one, as well as a friend of his, and another guy wants me to drop one into his Tacoma!!! If these guys are serious, that is adding a few more swaps to the list! They are piling up, may have to break off of my current shop and do these swaps full time.

On the way home, ran into the Granite State Euros gtg off of route 125 and got to show off the GTI some more!
 
Last edited:

cumminsfromthecold

Veteran Member
Joined
Oct 27, 2006
Location
HumCo
TDI
'84 Toyota 1Z 4WD x-cab
1Z Wiring, MIL light

"On the Passat B4 1Z [wiring] harness, G1/9 is where the MIL signal from the ECU comes in to the fuse panel, and is supposed to come out U1/9 but the Jetta cluster harness was missing connection U1/9, because the MIL signal travels on a seperate single connector, which is a yellow with white striped wire..I took a pin out of an extra fuse panel plug that had a male single pin plug that I inserted into U1/9 and plugged into the signal pin MIL connector voila MIL

I didn't figure this MIL connection out with just the wiring diagram, I simply bench tested the cluster and started grounding the various connections until I lit up the MIL...

the spastic power supply relay and phantom tach were caused by a lack of a engine to body ground...the ground cable for the battery to the transaxle is not enough..I figured this out doing continuity tests..hooked up a jumper between the head and body and that is solved."

Thanks GTiTDi - good info.
 

clyde

Veteran Member
Joined
Apr 8, 2000
Location
confluence, Snake/Clearwater
TDI
1998 Jetta, 1959 DeSoto with leopard-skin seat covers
Color codes?

all of the gray with white stripe wires get connected together. Maybe some of these pictures will help you:




In the top image of post 49, which shows the six different four-pin "connectors" that take single pin connectors, do the colors represent different systems? If so, what color means what system?
 

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
I don't think there is any real color code to the junctions, they are just common connection points outside of the relay panel. Like wires are grouped onto a common junction. I have never noticed any color designation for these in the Bentley manual.
 

compu_85

Gadget Guy
Joined
Sep 29, 2003
Location
Springfield VA
TDI
... None :S
Each group is a specific signal type though. One of them is dashboard illumination, black is switched power. The smaller single connectors are the K line.
 
Last edited:

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
So I have been installing a Sachs VR6 clutch, a windage tray oil pan gasket and new rear main seal...the stock clutch didn't have enough hold for RC3 tune...
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
MD
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
So I have been installing a Sachs VR6 clutch, a windage tray oil pan gasket and new rear main seal...the stock clutch didn't have enough hold for RC3 tune...
I'll be installing the same clutch fairly soon.
 

GTiTDi

TDIClub Enthusiast, Macht Schnell! Vendor , w/Busi
Joined
Oct 18, 2010
Location
3 Spruce st Wareham, gateway to Cape Cod Massachus
TDI
'91 GTI CJAA swap,'02 Jetta wagon ALH swap, '03 GTI 1.8T rally car, '03 Sprinter 3500
Well the trip to Waterfest was a blast, all except for driving on illogical New Jersey roads! Jersey barriers suck especially when the beer store is on the other side of the road and its two minutes to closing time! Used less than half a tank on the trip down hammering it the whole way! Filled up on B5 for 3.79 a gallon! The truckers at the service stop were doing double takes when they heard my whistlin turbo! Put the GTI to good use jump starting my buddy Janis' 900 hp Audi S2 "the Crow" which made a recent appearance in European Car magazine. His 4 inch side exit is ridiculous, Revving it up on launch control setting at 4am brought 5 cops to the hotel, who woulda thought that would happen! :D
 

clyde

Veteran Member
Joined
Apr 8, 2000
Location
confluence, Snake/Clearwater
TDI
1998 Jetta, 1959 DeSoto with leopard-skin seat covers
That's an ingenious way to have a stock-looking system that fits the flex air inlet tube. Looks good!

What air horn did you use on the inside of the MAF sensor boss? It looks a lot shorter than the one I have…


Modified the digifant airbox to work with the TDI airflow sensor...was going to get a mk2 turbo diesel airbox but when I picked up the mk3 intercooler parts and side exit exhaust, I was shown a digi box that was cut up to fit the airflow sensor boss from a mk3/b4 airbox but it was missing the sensor boss. So after a little cutting and hot gluing, here are the results!


 
Top