VW TDI forum, Audi, Porsche, and Chevy Cruze Diesel forum banner

1 - 20 of 29 Posts

·
Registered
Joined
·
26 Posts
Discussion Starter #1
i have a 98 tdi jetta and it is in limp mode and i cant figure it out iv'e changed injection pump,n75 checks good all vaccum lines check good including computer line.has a new turbo and actuater on it and im just lost need help please and thanks.
 

·
Premium Member
Joined
·
5,942 Posts
Yes, his post said that he changed the vac line inside the computer :)
He says they check good including the computer but nothing about changing them or if he actually did the one in the computer. As we both know looking good and being good are two different things so I thought it best to check.:)
 

·
Registered
Joined
·
26 Posts
Discussion Starter #6
yes guys i have changed both lines with new and i dont get any codes just strong power right off then gone pretty quickly basically almost anything off 1500rpm is sluggish and i have looked through the limp mode problem section and this is what i have done i have a new turbo and actuator i have a tested good n75 opens and closes correctly and i have a known good injection pump change and i have all timing set correct starts quick and the crank gear is great not wollered out and anyone can think of something for me to try i am up for it let me know i need help asap and i really appreciate all the quick responses from u guys a newbie like me i have seen beat to death on other forums its crazy sometimes but anyway thanks alot.
 

·
Premium Member
Joined
·
5,942 Posts
How about the anti shudder valve, have you checked that it's fully open? Have you tried running the car with the maf unplugged? Is the inlet manifold nice and clean? Are the boost pipes all in good order with no splits or faulty connections? And don't mind us lol, it's just discussion stuff.:)
 

·
Registered
Joined
·
26 Posts
Discussion Starter #8
yes i checked all boost hoses and connections i dont have an anti shudder valve these 1z motors dont have them and yes i just did a run with maf unplugged runs exactly the same as with it plugged in but i have a known good one that i changed it to earlier so idk keep suggesting so i can figure this out please and thanks agian
 

·
Premium Member
Joined
·
5,942 Posts
Just to be clear, the car is lacking power permanently? The power doesn't come back when you restart the car? Is that right?:)
 

·
Registered
Joined
·
26 Posts
Discussion Starter #10
it has the same power all the time no matter what im wondering if my waste gate is moving and how to check it.
 

·
Premium Member
Joined
·
5,942 Posts
Limp mode is when you're driving usually up hill and the power suddenly goes but it comes back when you restart the car. But what you have is just permanent low power, was it a new turbo or just new to you? The wastegate setup uses pressure in the lines to close the wastegate unlike the vnt which uses vacuum to work. Here's some stuff I found about the wastegate turbo, there's a chance your WG is stuck open but if you've fitted another turbo then you should be able to get to the actuator and make sure it all moves freely.:)

http://www.myturbodiesel.com/forum/f9/wastegate-turbo-how-works-6457/
 

·
Registered
Joined
·
26 Posts
Discussion Starter #12
it was a turbo with 10000 miles on it but guy i know bought it new and what are best places to look for my problems then
 

·
Premium Member
Joined
·
5,942 Posts
Now that's a tough one, me and you are in the same boat with having wastegate turbos instead of vnt ones. Did you check the actuator was free and the wastegate wasn't stuck? I'm not sure how you reach it on yours as I have the ko3 and you have the garret but you might see it from underneath if not from the top. When did this all begin? Had you been working on the car then it had low power or did it just suddenly come on one day? Does it rev up fine when it's in neutral?:)
 

·
Registered
Joined
·
26 Posts
Discussion Starter #14
it revs fine in nuetral or in gear just when u go its sluggish and the wastegate seems to be free it all started my original motor got hydrolocked from a water puddle and then i put this engine in got it going good except for limp and i know this engine was good bc it was in another car i took it from and it ran good but i reused my injection pump which is good and now it runs limp idk just hunting game now i guess.
 

·
Premium Member
Joined
·
5,942 Posts
Yeh it sure is, it's always the same but it'll be something simple, maybe something missed or something not quite set up. It's hard trying to diagnose it too when you're not there, that's the only problem with forums. Were both cars manual gears?:)
 

·
Premium Member
Joined
·
5,942 Posts
That's a pity because the manual and automatics have different pumps and injectors and that would've been an easy fix lol. If the engine was good in the other car but a bit poor in yours then you've deffinitely missed something. Have you checked the timing etc with vagcom? Is there any smoke at all?:)
 

·
Registered
Joined
·
26 Posts
Discussion Starter #18
well i dont have anything but the cheap vagcom cord from ebay so i cant check that timing is spot on it run good starts quick and puts out little bit of black smoke when revved hard.
 

·
Premium Member
Joined
·
5,942 Posts
The black smoke might indicate something, it can be caused by a boost leak, did you do a proper test or just check over the pipes? There's a how to in the faq's for doing a proper test for any small leaks. The other thing would be IQ settings, they might be out which could also cause a bit of smoke. Send me a pm to activate yours, I can't send you one until you send one first.:D
 

·
Registered
Joined
·
26 Posts
Discussion Starter #20
--------------------------------------------------------------------------------

hey yea thats what i was wondering if the iq is out on it because the guy that i bought it from had run veggy oil in it for 40000 miles and i did boost leak check and there are none also timing is off a little bit to and another question for u is that im buying vagcom tomorrow and was wondering which i should buy i can afford up to the $700 one on ross tech and dont need to do anything newer than mk5
 
1 - 20 of 29 Posts
Top