D-Jetronic Bull-Shnizit, ...whats the deal? Options

[ArtechnikA]

QUOTE (Bezerker420 @ Jun 24 2005, 03:39 AM)

Type I's are turboed like crazy....arent T4's? or is is a porsche engine bay space thing....? haynes says i need a CO monitor to tune the air/fuel ratio .... with only 87,xxx mi I dunno how the tranny could be so shitty felling....

turbos: it is a "there aren't enough T-IV people who want to pay the money to do it right to make it worth building a kit that people will bolt up to original engines and be pissed off when they break" thing.

a CO monitor is nice and not that expensive but if you fix and check all the stuff that can be done without it, you should find the CO will be correct. you cannot "just" tune the air/fuel ratio. you adjust the stuff like the fuel pressure regulator and make sure your manifold pressure sensor and cylinder head sensor are working. if they are - your mixture will be correct. if they're not, nothing you do will make it right...

your tranny can be shitty-shifting because the original 87,xxx mi rubber transmission and engine mounts and plastic shift linkage bushings are 35 years old and falling apart. your fuel lines are probably in the same shape, so be careful...

[newto914s]

QUOTE (Bezerker420 @ Jun 23 2005, 11:39 PM)

but with only 87,xxx mi I dunno how the tranny could be so shitty felling..

Change the shift bushing. It made a huge differance in my car
http://www.pelicanparts.com/catalog/shopca..._pedals_pg1.htm

Check out Brad's page. That resoure and this book and you should be able to tackle any D-jet problems. I picked it up at the public library.

A quick fix(meaning not the best) is to raise the idle with the air bypass screw on the throttle body. That will keep it from stalling at lights, untill you've read up and can fix the problem correctly

[Bleyseng]

Stalling out can be fixed by:
#1 New points, plugs, condensor, cap, rotor, wires, clean all FI grounds, battery terminals, tranny strap ground connections
#2 Adjust timing to 27 degrees BFTDC @ 3500rpms with a timing lite (check marks first)
#3 Adjust valves (cold) before starting engine to .006
#4 Check for vacuum leaks and replace all old hoses and install new O rings and gaskets
#5 Adjust idle mix and speed with the engine hot
#6 Lube the AAR valve with a couple of shots of PB Blasters (not WD40)

Car should start up cold and idle at 1500-1800 rpms and after 5-10 minutes settle down to a sweet 950 rpms and stay there even when at a stop lite. Throttle response is instant and there should be no hesitation off idle to cruise.
No bucking at 3000 rpms as thats caused by a bad TPS.

[Jake Raby]

The Turbo thing on a TIV Vs. a TI goes very deep. The TI has an exhaust port that is better for Turbo than a TIV simply because it's the strong point of the head. With any Turbo engine the exhaust heat and pressure is the key and with the TIV we just don't have that port characteristic in the factory heads.

My Billet heads will be great for Turbo, I am building a Turbo TIV with them now.

Sure you can Turbo a TIV with the right machining and thoughts and components, BUT since the gains are not as big as they should be it simply isn't worth the effort at the present..

[Bezerker420]

yeaaaaaaaaaaaaaaah....i moved...outta the 2bed apartment into a 4 bedroom house.....no driveway house is like 4 feet off sidewalk, and the garage is only like 8 feet deep and 6 feet tall.....[the previous tenants grew tons of pot and moved walls around to suit their "needs" so i only have storage, not workspace.... (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif) ]



im curious/confused why VW would have moved backwards to a "weaker" casted head on a TIV then from the earlier engines...?

jake....how far north are you from fayetteville? my GF's family is all from there.....and one whole branch of my fam tree is from rome/carrolton....I visit georiga more often then most others, and im gonna have to stop by and check out your new digs....



sorry for asking.....but [years ago] a guy i knew put a huge/nasty T1 in his 912 cause a new motor [912] was same price as a monster T1....why couldnt/shouldnt i do this with the 914? with a bus case maby to mount it?

[lapuwali]

QUOTE (Bezerker420 @ Jul 14 2005, 10:04 AM)

sorry for asking.....but [years ago] a guy i knew put a huge/nasty T1 in his 912 cause a new motor [912] was same price as a monster T1....why couldnt/shouldnt i do this with the 914? with a bus case maby to mount it?

Fully built Type Is don't tend to live very long. From everything I've heard, you're lucky to get 50K miles between rebuilds. The Type IV is much more robust, and a 2.3-2.5L T4 will last a lot longer than a similarly sized T1.

The T4 was designed just as the emissions era began, so the heads are the way they are partly for good emissions reasons. Later, people figured out how to get good emissions with power (catalytic convertors and good EFI), but in the late 60s, mild engine tuning and fairly crude EFI were the best that was available. This compromised the engine design, and many of these compromises have to be undone today.