VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: boosted_diesel_84 on January 30, 2008, 08:24:11 am
-
what is exactly done, and what are the benefits? thanks for any help
-Jack-
-
You shim the main spring, which allows the IP to keep on fueling at higher rpm's rather than cutting fuel back at around 3500. Just do a search for the make your 1.6td a faster car in the FAQ section. Don't bother with the intermediate spring mod.
-
I thought the mod. was done with the intermediate spring?That what i was told.What is the difference between the two?I thought you wanted the full travel of the "unlimited"spring..Replace the middle"intermediate spring with tubing,and your good to go. i was not aware of a main spring modification. :?:
-
Sorry my bad.I must have viewed a different thread.I wasnt aware of the main spring.How is my pump going to act with just the inter. spring replaced?I used some brass tubing a hair wider then the spring.I thought you wanted the main spring travel. :oops:
-
It's harder to maintain a lower to mid rpm at light loads. If you are coasting down a hill, the pump will try adding a little more fuel, not a lot, as the rpm's increase. Acceleration will be good, but it does nothing for the fuel being reduced at higher rpm. It's more of a pain than anything in my opinion as that's what I did also.
-
so your saying i shouldnt do it? right now, everything is apart, pump is being rebuilt, and im going for fuel economy, but if it wont hurt economy i will do it, what is your experience with it?
-
Shim the main spring, don't touch the intermediate spring. Fuel economy is in your foot.
-
ok,cool, i just wanted to verify before i go and screw my fuel economy,lol, thanks!
-
So it would only be in no load situations(with foot off pedal)?In other words not that often?Im just trying to justify leaving it in .Ive already got my pump all sealed up i dont think i wanna take it back apart.It is out of a vehicle right now though,so if you think this is gonna mess with the economy that much,please tell me.
-
Not no load, low rpm or low load. It isn't a problem when your foot is in the pedal. It's like if you push on the pedal so far, it pushes on it farther by allowing the governor to add more fuel. I believe this is why people who do the intermediate mod often need to unscrew the residual fuel screw because the motor starts running away if it idles to high. You can drive with the mod, but you may have to let off the gas to keep from accelerating. Case in point: when I got my car dynoed, they had a hell of a time keeping the rpm's constant as the engine wanted to keep speeding up as it added more fuel.
-
Thats enough for me i susspose.I got an lda from a peugoet and i was thinking about using its inter. spring as it was stiffer.I measured it and it was a little larger.What effect would this have?
-
Jimfoo do you have your mainspring shimmed?
-
No, back when I did the mod there wasn't the advice to not do the intermediate, so that's what I did, and I didn't think I wanted the mainspring shimmed. I know different now. A stiffer intermediate might not be too bad to try depending on how much stiffer. I'd say give it a go.
-
Im going back in!!! :D I found a place thats got the little circlips on the end of the assembly.As my pliers seem to be destroying them.Im going to go with the stiffer spring heres a pic of it installed before i did the inter,spring
(http://i249.photobucket.com/albums/gg206/2253benjamin/volkswagendiesel006-1.jpg)
-
Man, my intermediate spring is nothing like that, but if that's your current one in the background, then, yes I'd do the switch as it doesn't look that much different. I take that back, my spring is similar. I guess I must be remembering something else as I found my spring sitting here. Yes, go for it.
-
Well its done ,i had no problem getting in and geting out.I didnt shimm the nain spring,as it seemed to hard to hold down and get the circlip. :roll:
-
so i am confused, is the govenor mod with the main spring or the intermediate spring? and which one is worth doing that wont hurt fuel economy but will help power, and this is on a TD if that makes any diff. thanks!
-Jack-
-
I don't know think either helps economy much, but economy depends on your foot. Do a mod, put in more fuel and you get less economy. The mainspring shimming is the only one that should be done if you do anything. It lets fueling continue to higher rpm's.
-
sorry, im a dumb a$$, but on the thread for the governor mod it shows eliminating the intermediate spring, but you are telling me to shim the main spring. which one do i do? isnt the governor mod with the intermediate spring? what is purpose of shimming the main spring?
-
Remove intermediate spring, put something in its place so that it is preloading (compressing) the big spring about an 1/8 to a 1/4 of an inch.
-
Remove intermediate spring, put something in its place so that it is preloading (compressing) the big spring about an 1/8 to a 1/4 of an inch.
No, it is hard to drive with the intermediate spring removed. ONLY the main spring should be shimmed.
-
Remove intermediate spring, put something in its place so that it is preloading (compressing) the big spring about an 1/8 to a 1/4 of an inch.
No, it is hard to drive with the intermediate spring removed. ONLY the main spring should be shimmed.
I know this is a old thread but I think it's important for new people to read this thread.
I COMPLETELY agree with jimfoo on this and the reason behind it is I tried removing the intermediate spring and replacing the main spring with a piece of hose/ shimming it. Anyway I used some washers to replace the intermediate spring and put it together.
Idles fine as expected but I cant get it to idle back down, tried backing the idle screw out a tad then even backed out the max fuel screw a bit and no go. Even re indexed the throttle shaft to try to get it to have better throttle control, nope shut down there also.
I'll be removing the top of the pump again tomorrow and reinstalling the intermediate spring so I can drive the dang thing.