16v Digfant II FAQ

[snowj420]

what is a "Digifast Chip from vw pilot on the tex"? i'm about to do a swap and this is the only thing i can't figure out from your post. everything else is crystal clear. thanks for posting this in such detail. it's going to make this little dream of mine come true finally, a hot little 16v (from my 87) into a beautiful 91. i can't wait to post pics of it when it's done.

[rychas1]

vw_pilot@hotmail.com just ask for a chip. best $ ull spend on this swap.

[GutlessLump]

agreed, it really smooths everything out, just dont expect a hp gain. i really didnt notice anything other than better drivability.

[MFZERO]

just wanted to throw these in here, dyno'd my swap with just a header, 264's, stock digi2 everything else, removed the inlet fom the air box and deleted one muffler:

[rychas1]

nice power.

[MFZERO]

thanks! everyone there was impressed when I hit that. I think the car may have been off for all of about 5 minutes after i drove 40 minutes to the dyno then I went right in and was strapped down. i think it might be a little higher if it were cooled off. need to chip it to get the a/f better

[Jankenstein]

Nice Thread you guys got here. i havent had time to read the whole thing but i did happen to find a few people that have been expieriencing similer idle issues at start up...but have found little in terms of a solution?

let me start by mentioning that i completed my swap 2 years ago this spring. i kept mostly everything stock with the excpiton of a chip and the standard breathing mods. and i must say it was by far the most simple way to put a 16V into a late mk2! Everything went Smoothe and with the excption of having my feed/return fuel lines swithched somehow ...

the car started/ran/revved and pulled hard off the first crank. the only issue that had me purplexed was that of a serious bogging when i gave it full throttle from idle. i thought it was an ignition issue but with everything set up to the book the hesitation was quite evedant.
after alot of playing around, trying slightly different settings of timing Air/fuel mixture and idle i finally got it to idle just over 900 rpm and rev up smoothely right from idle...to 7000(as far as ive taken it)....

However it comes not with out SACRAFICE.

since clearing this hesitation up it has the worst time finding an idle for about the first 30 secconds after start up. it revs up and dies off back and forth seemingly hunting for a specific range. it always settles down and is problem free with great idle and strong accelleration.

i havent tried setting back to exact spec because its only been taken out slightly.

As for that problem ill keep plugging away at a few ideas that i have to solve this and ill keep updatad.

But one thing i have been curious about is my crankcase breather hose. Should that be meterd air or not ive seen people run it both ways. into the intake pipe, into the bottom fo the air box and not at all with just a little cone filter on it. whats standard? id like to hear any input on this.

other than that i couldent have a more reliable fun to drive mk2 for the money i have into it!

thanks for reading
cheers

Modified by mikejank at 10:29 PM 2-13-2007


Modified by mikejank at 8:05 PM 2-16-2007

[ryansux]

unplug your isv, and set the idle manually....yay I hate those isv's

[Jankenstein]

ive done that before and it wont start when its cold that way.....or maby its when its warm..i cant remember. dident work for me

agree on the hatred for those POS ISV's!

[gruvismalt11]

iv never had a problem with my isv being unplugged in fact it seemed to clear up idle issues. i would not suggest using a cone filter this method has proven to be dirty

[8mann]

If I didn't know any better, I would have thought I wrote your message. I have the exact same idle issues you describe. I have tried a number of things and can't seem to resolve them. Maybe my next move would be to remove the ISV.

I am curious to hear what people think on the Crankcase vent. I have had it vented into the intake and also floating loose. Didn't notice any difference other than the build up of oil in the intake. My current setup is just floating the hose into the bottom of the filter box.

[rychas1]

my crankcase vent is routed into the intake. i took it apart recently when i did my timing belt. for 2 years of beating the snot out of this PL, i had very little oil on my throttle body. ive seen filters slapped on the end, but why fix what aint broke

[GutlessLump]

Quote, originally posted by 8mann »

. I have had it vented into the intake and also floating loose. Didn't notice any difference other than the build up of oil in the intake.

put some steel wool in the top of the vent line to catch the oil...works fine. just make sure that it doesnt have a way to get into the engine. i just crammed some in there and it never moves and still breathes just fine.

i've ran my vent open to atmosphere and back to the box, noticed no difference in tail pipe emissions or performance either way.

[vdubmike2]

if your swapping digiII into a cis 16v car do you have the change the fuel pump? i know the cis unit runs about 70psi while the digiII unit runs only about 30psi, would it wreck the fuel pressure regulator or is it fine the way it is? thanks

[rychas1]

it has been done before, but i cant recall the results. scrape this thread real good. its in here.

[MKII91'GTI]

ok with this swap....is there a good difference...or a bad difference.....more power....less power.....etc.....i know if i were to do this...i have the opition of boost....but is there a huge change in anything.....cuz to tell u the truth...im tried of mine....cis-e motronic..

[vwpat]

Quote, originally posted by MKII91’GTI »

ok with this swap....is there a good difference...or a bad difference.....more power....less power.....etc.....i know if i were to do this...i have the opition of boost....but is there a huge change in anything.....cuz to tell u the truth...im tried of mine....cis-e motronic..

Good difference, more smoother power but I would not boost with digi II, it is not digi I.

[RDM]

heres another semi successful swap. definitely going to swap to MS in the future.

[91GolfGL]

What wiring harness can you use the 8V , 16V or either one?

And what would you have to due to switch a digifont 2 car over CIS or what the 16V came as?

[rychas1]

use the 8v one. u only have to lengthen the injector harness.

[91GolfGL]

Thanks. But what if i can only get a 16V one will it still work.

[rychas1]

a 16v harness? not on digi2. different sensors.

[Andy Bro]

Alright guys, I've been having this intermittent problem that I thought I've fixed a few times, but so far I'm stumped. Its a '92 Jetta Digi 2 2.0 16v and its running rich all the time, I rev it up and I have a ton of black carbon shooting out the exhaust. The old engine that was in the car had a ton of carbon in the cylinders. I've replaced the MAF with another one I had when I had the problem a while ago, and it seemed to go away, I still had a gas smell in the oil, but the stuttering and lack of power went away. But now, with the new engine in, different CTS's by the way, I have the problem again, and its as bad as ever. I put a new O2 sensor on it, and I just checked and its putting out 300~600 mV at idle.

The CTS is putting out about 3400 ohms, and even when I jumper the connector with a wire, it still runs rich if smell the exhaust. I don't know what else could cause it?

It may be related or not, but I have a funky idle where sometimes it will idle at 1300, other times at 800, but a vacuum leak would cause it to run lean, and I don't have any other symptoms of a vacuum leak, I don't think so at least. I have another ECU I'm going to throw at it this afternoon, but I wanted to hear what you guys have to say about it.

[rychas1]

what ur ecu look like? stock? good condition?

[JetBlack16Valve]

Ive been reading thru this thread and it seems like people are making pretty decent hp gains. I have all my digi 2 stuff in boxes in the garage from when I swapped in my 16v...looking to do some tinkering and debated this before. also debated going digi and boosting. But if I can make some gains essentially for free then I might just do this to start. Whats everyones round about power gains?

[rychas1]

hard to say if anyone is 'gaining' power by using the digi2 management. after all, its not a 'power-making-easily' system. tho some have made more than stock numbers, mod for mod, over CIS-E or motronic, but again...some...few...very few. but a lot has been proven with this system, and a lot more to go for those that want to make the most of it. most ppl give up and go to something easier like msns or digi1. untuned, on basically a stock 1.8, i made 104/104 thru a 3spd tranny. not big numbers by far, other than that the power was peaked at 6300

[JetBlack16Valve]

then is it not recommended to go this way?

[Andy Bro]

Quote, originally posted by rychas1 »

what ur ecu look like? stock? good condition?

Yup, the ECU is stock, I swapped out another stock one and got the same effect. I ran about 10k on the swap so far, and I had some problems with a bad MAF that gave me a nasty stuttering problem, now I have a problem with it running way rich (a few thousand miles after the last problem). It has a new O2 sensor, CTS checks out ok, ECU wiring tests checked out ok. A suggestion I got was to swap out the FPR with a known good one, and to blast out the return line in case that clogged. Other than that, I'm honestly stumped. There must be something I'm overlooking.

[rychas1]

Quote, originally posted by JetBlack16Valve »

then is it not recommended to go this way?

if the car did not come with digi2, i would not waste time installing it. most ppl who have digi2 16v, like me, had digi2 already on the 8v. dont make more work for yourself. now, if u have digi2 already, it IS the way to go. easy swap and more power from the 16v. if ur looking for serious power tho, this is NOT the way to go. digi1, msns, standalone, etc is, especially for turbo or supercharged 16v

Quote, originally posted by Andy Bro »

Yup, the ECU is stock, I swapped out another stock one and got the same effect. I ran about 10k on the swap so far, and I had some problems with a bad MAF that gave me a nasty stuttering problem, now I have a problem with it running way rich (a few thousand miles after the last problem). It has a new O2 sensor, CTS checks out ok, ECU wiring tests checked out ok. A suggestion I got was to swap out the FPR with a known good one, and to blast out the return line in case that clogged. Other than that, I'm honestly stumped. There must be something I'm overlooking.

ECU needs a chip, but first check the fpr. other than that, if it aint a ground or vaccuum, i dont know. maybe someone else can chime?

[njnene78]

if the car did not come with digi2, i would not waste time installing it. most ppl who have digi2 16v, like me, had digi2 already on the 8v. dont make more work for yourself. now, if u have digi2 already, it IS the way to go. easy swap and more power from the 16v. if ur looking for serious power tho, this is NOT the way to go. digi1, msns, standalone, etc is, especially for turbo or supercharged 16v

my jetta was at one time digi2 but some did the swap to 16v when i bough the vehicle and now i want to try digi2 but keep the 16v what do i need.

[rychas1]

Quote, originally posted by njnene78 »

my jetta was at one time digi2 but some did the swap to 16v when i bough the vehicle and now i want to try digi2 but keep the 16v what do i need.

so ur saying the car was once digi2, then someone put in a 16v with 16v management? and u wanna go back to digi2, keeping the 16v? if that is correct, all u need is a digi2 harness and the digi2 sensors. but if the car runs fine the way it is, leave it!

[JetBlack16Valve]

hey did i hear it right when someone once said a digi 2 harness can be converted to run digi 1

[rychas1]

yea the guys at SNS here in atl figured it out. i have yet to see a running system..and i think in the end, it is still easier just to use a whole digi1 sys.

[JetBlack16Valve]

if there is no benefit to digi 2 over cis then why not swap everything in from the cis?

[rychas1]

your not swapping anything but the 16v engine. 8 more valves and tons more high end power. for example in my case, my 8v pooped out...i needed an engine, my mechanic had a 16v, in it went. i had no goal at that time other than a functioning daily car. then i went nutz i was saying that very few people will yank out a good runnng cis or motronic, just to run their 16v on digifant 2. im sure it has happened, jsut not very often.