TS 2 question & others...possibly stupid??

[drozdenko]

Hi,

Couple questions from you all…

Some background: 79 bay camper, new engine ~1000 miles (suburban engine), everything tuned up (timing 28-30 with hose off, around 7.5 deg, valves adjusted, plugs new, cap/pertronix), fuel/vac hoses new. Just about everything else is new.

I have VDO CHT, Oil press & oil temp gauges (CHT temp is located in the boss to the right of the #3 cyl), oil temp sender is in the taco plate

Q1) My oil temps are high (220) after a 20 min ride home on highway, 55 mph, CHT temp is 340, oil press is around 25-30. The other day I thought 220 was too high so I pulled over and did the “dipstick” test.. the exterior (hook) end was warm but not so hot that I couldn’t grab onto it. Do you think the gauge is far off or is that temp a concern? Oil is 20-50, air temp is around 85-90 humid

Q2) Bus starts ok cold & hot but the idle leaves much to be desired…it stumbles a little, fluctuates..never stalls but not real smooth. I read the bazillion of posts trying to narrow down the problem..i checked for vac leaks using start around all the connections and didn’t find any. I looked at the AFM and read Colin’s post about where the mid range in (4.5). I turned mine in and noticed it was only 1. Not having a a-f meter I didn’t want to mess with it too much but I adjusted it out to 2..drove for 1-2 days and it was the same. Last night I changed the oil and then for the heck of it tried turning the AFM screw while the engine was running..all the way in made the idle nice & smooth which leads me to believe there's a vac leak.
i sprayed starting fluid over all the hose connections again & nothing. I read posts about the TS2, mine is new but i noticed that when i installed it i added a large washer to capture the tin..then it got me wondering if that washer is messing up the readings and maybe not bottoming out the sensor?? Is there a need for a washer or do you think that would cause the TS2 readings to get messed up?

I don’t have a a-f meter but I’m working on getting one for next week.

Any other suggestions to check??

Too bad Colin wasn’t passing thru CT earlier or I would book him for a day. I’m hoping to have this figured out earlier but maybe I’ll see if he’s free anyway to double check everything.

Thanks for any help!

Lee

[poptop tom]

Hi Lee!

Regarding Q 1, I'd say that 220 is just fine for a new rebuild and those kinds of ambient
temps. The vdo gauges won't figure in the ambient temp like a dakota digital will, but you probably aren't far off with your readings. And your 340 cht temp is fine.

Q2, I would say that the washer shouldn't be there at the TS2 and would have an adverse affect on its operation. I would remove the washer and see how things are before going any further with other adjustments.

[drozdenko]

ok, thanks for the reply! i'll do that tonight when the engine is cool.

[drozdenko]

I removed the washer and reinstalled the TS2..not a big difference if any. drove around all weekend and to the terryville VW show.

Started this morning (cold, outside temp ~60)..starts fine, high idle..when warmed up the idle seems to fluctuate. any idea what that might be? maybe because i'm running rich? (only reason i might think that is b/c the a-f mixture screw is only 1 turn out)..i heard ~4 is the "starting point".

I'm hoping to get the a-f meter this week to see where i stand there.

couple more questions:

1) i know it's been discussed bazillions of times but what's the scoop on hydraulic valve adjustments. I heard from 0 lash to as much as 1.5 turns in. is there benefits either way?

2) does the intake plenum make a hissing noise when running? i keep hearing it thinking it's a vac leak but can never find the source.

Thanks!

Lee

[drober23]

I'll take a shot at some of this,

AFM Adjustment: ~4 is a starting point, and things can be adjusted from there.
The reason it is used as a starting point is that it is halfway through the adjustment range. Giving you room to adjust it either way if needed. There is no guarantee that only being 1 turn out is the result of a vacuum leak, but, the fact that turning it all the way in "helps" the idle may be an indication of one.

It may be tuned around the vacuum leak for a solid cold idle. Sometimes we start to compensate for things to get the engine to run "right". Turning the mixture screw on the AFM is one of these things. If this is the case, it could cause an issue at other operating conditions.

There should not be a hissing sound coming from the intake plenum. This is another indication of a vacuum leak. There are a couple possible things that can leak vacuum there.
1) Missing vacuum line. There is a T for a vacuum line one the plenum, and another on the back of the throttle body
2) Gasket from Cold Start Valve: if this is damaged/missing it might cause a hiss
3) Hose to Brake Booster: if this is missing or damaged it would cause a huge vacuum leak
4) Gasket from throttle body to Plenum: This makes a good hiss if it has not been installed, and could cause a smaller hiss if damaged
5) Connection from intake manifolds to plenum: The short rubber hoses can leak, and a bad leak may cause a hiss

[Amskeptic]

Quick notes after my Anaconda Montana - to - Ogden Utah run today.

Intake plenums can sound hissy and it is just the idle air passing around the throttle plate.

The number of turns you find the mixture screw at, be it 1 turn or 4, is not an absolute. It is just where you happen to find it. Yes, a screw found near the bottom suggests a change in operating parameters. There is nothing wrong in your bottoming it out to make it idle better for now. When we adjust the black cog and wiper, then we would of course move the idle screw to 4 1/2 so you have more adjustment range in the future.
Colin

[drozdenko]

ok, sounds good.

I'm looking forward to your visit in Sept.

The bus runs but I just know it can run better.

Thanks!