Autostick hesitating when stopping in gear

[sb001]

If you scoured the samba you probably saw my thread over there about this situation, the "sick of this" thread. Which disintegrated into a rant on VW clubs, but whatever.
Fuel bubbling in fuel filter is completely normal. I wouldn't worry too much about that. I swapped my fuel pump out several months back for a NOS Brosol (VW OEM supplier) pump, and it could be fuel pressure related but you would think that would happen all the time too, not just when it's hot. And when the car idles, not just in gear.
I really think we have to think outside the box here--something that is related to the car being in gear, and hot. I'm wondering if it's possible our 12mm hoses going from intake manifold to control valve are poor enough quality that they collapse in a bit when they get too hot and under vacuum pressure from the autostick system. I swapped this hose last year when I was having work done on my engine- before that I had the stock 12mm wire reinforced hose and don't remember ever having this issue. Or the times I drove it over the winter months.
I don't know what it is but it really is driving me nuts.

[jovanybg]

I've swapped my PO mounted garden hose to real 12mm. vacuum hose from the control valve to the servo and that didn't change the behavior of the car at all!
I am more and more inclining towards the fuel delivery to the carby. Browsing through Samba forums shows a lot of "Hard start when hot" sufferers! Most of those symptoms disappeared when an original, rebuildable fuel pump was installed. That pump had a fuel relief that drops the pressure of the fuel to zero after the car is stopped. The newer fuel pumps do not have that and the fuel gets warmer and warmer, expands more and floods the cardy, leading to a hard start when the car is still hot. I have that symptom too and will look at taking care of that on the way to finding solution to the hesitation in gear....
I've looked at my engine tins and as far as I can see there are no missing pieces, so the cooling should work just fine...
Another thread in Samba shows that using 20W-50 motor oil during the summer might lead to overheating too... Because it is so easy switching to 10W-30 or 10W-40, I'll also try that remedy and see if it helps or not?!

[sb001]

Honestly I don't think any of that has anything to do with our issue. I swapped my pump several months back for a brand new old stock Brosol (VW of Brazil) pump, which was the same EXACT pump  had been running before without these issues (I only replaced it because the old one was leaking out around the top rim.) I know what you are referring to about the old pumps pressure going to zero when you shut the car off--they have a check valve that doesn't allow any more fuel through after the engine is shut down, which this replacement of mine does have. The newer ones don't. However having said that, I drove it around the other day and took the air cleaner off after getting back home and noticed fuel still being pumped out the accelerator pump nozzle in the carb!
I have a couple VW guys coming over today to help me look at this--we ca measure fuel pressure out this pump as well as some other stuff. There are some interesting theories being floated around on the samba, like maybe with the hear our clutch arms are not adjusted properly and are engaging a bit during stops after engine warm causing the RPMs to decrease. After all the low idle only seems to happen when car is in gear, engine up to full operating temperature and warm outside. I don't know...

[jovanybg]

Please update on the findings!!!
Hopefully today the VW gurus help you will find the reason!!!
I'll post any more observations/findings on my end too!

[sb001]

Please update on the findings!!!
Hopefully today the VW gurus help you will find the reason!!!
I'll post any more observations/findings on my end too!

You stated above that you swapped your aftermarket garden hose out to a real 12mm vacuum rated hose. Where did you find this hose? Part #, etc?

[jovanybg]

You stated above that you swapped your aftermarket garden hose out to a real 12mm vacuum rated hose. Where did you find this hose? Part #, etc?

Welcome back to this forum!!!
We agreed on the hose for vacuum to be a metal braided, but as sb001 stated even using the correct hose didn't help the issue.
Now I've changed my oil to SAE 40 Valvoline RS1 in place of the 20W-50 I was running and will update if that has something to do with the issue.
Another member on Samba suggested to check the temperature of the throat under the carburetor - possibly ice forming in there. I'll check the temperature once I have the car out and hot.
What else can I check/change?! As sb001 said "running out of ideas"....

[anilLiAnCe]

hey guys. so here are a few things to check regarding the hesitation. tighten the two bolts that connect the manifold and carb. make sure that the throttle cable doesn't kink. check for icing on the manifold when car is hot.

[jovanybg]

tighten the two bolts that connect the manifold and carb

Tightened!

make sure that the throttle cable doesn't kink

It is straight as an arrow.

check for icing on the manifold when car is hot.

There is no icing, but definitely cold temperature compared to all the hot parts around!
Isn't it normal to be cold?!

[anilLiAnCe]

you need to have someone sit in the car and have the person inside press the gas pedal fast and regular and while you are at the engine looking at the cable. even the slightest curve can result in hesitation. what kind of gas do you use in your car? also the fuel pump rod could be getting stuck causing vapor lock.
http://www.vw-resource.com/vapor_lock.html
and normal is warm not cold.
check your ATF fluid to see if its low. should always be between dipstick marks.

[jovanybg]

you need to have someone sit in the car and have the person inside press the gas pedal fast and regular and while you are at the engine looking at the cable. even the slightest curve can result in hesitation.

I've done just that and the cable is all straight!

what kind of gas do you use in your car?

I've putting only Shell Premium in.

also the fuel pump rod could be getting stuck causing vapor lock.
http://www.vw-resource.com/vapor_lock.html
and normal is warm not cold.

I will double check, but here I might have a slight problem. Last time I've checked under the carburetor it was cold to the touch!!!

check your ATF fluid to see if its low. should always be between dipstick marks.

I am checking the ATF fluid regularly and only once I've needed to add some, but it is always between the marks!

[anilLiAnCe]

shell premium so 91 right? try switching gas brands from time to time. i personally have never liked the way my car runs when using shell (whether or not its all in my head). i alternate between 91 arco and 91 chevron. and every so often i mix a 50/50 solution of 100 octane with 91, which really makes a difference.

do you have heat risers? or j tubes? has the manifold always been cold or is this just something you've noticed recently? do you have a mechanic or shop that you go that specializes in vw beetles including autostick?

[volkenstein]

jovanybg,
             On your intake manifold - as you are looking into the engine compartment, the right side of your exhaust is meant to supply
exhaust gas through the small pipes (heatrisers) where it is blown out by the left side. "Cool"/"Slightly warm" on the LEFT side just doesn't cut it for good running. if both small diameter pipes are cool-ish to the touch - then your heat riser pipes are blocked. You can unblock them, but be prepared to get some quality filth inducing shed time. Took me most of a Saturday to use a drill with different lengths of clutch cable attached and reaming the manifold out. Got a welder? can speed it up if you drill two holes at where the heatriser pipes bend.

Miserable sod of a job......

HTH
Volkenstein

[jovanybg]

shell premium so 91 right? try switching gas brands from time to time. i personally have never liked the way my car runs when using shell (whether or not its all in my head). i alternate between 91 arco and 91 chevron. and every so often i mix a 50/50 solution of 100 octane with 91, which really makes a difference.

Premium in Texas is 93. I have only a good experience with it with all my other cars... It should be good for the Ghia (I hope)

do you have heat risers? or j tubes? has the manifold always been cold or is this just something you've noticed recently? do you have a mechanic or shop that you go that specializes in vw beetles including autostick?

I do have risers. What is cold is not the manifold or the risers, but the throat under the carburetor and the flange under the carburetor. I was finaly able to measure my fuel pump pressure tonight after spilling some gasoline on the first try due to a defective plastic tee provided with the gauge. Tonight I've run the car idling for about 5 minutes and the pressure was constant 3.5 psi. After 5 minutes of idling I measured 127F on the risers, 195F on the sump of the engine and 72F on the flange under the carburetor. It really felt cold to the touch, but the laser thermometer  showed only 72F. There was moisture on that throat - cold condensation, as it is always humid in Houston.
Isn't it normal to have that cold of a temperatures on that throat?!

[jovanybg]

jovanybg,
             On your intake manifold - as you are looking into the engine compartment, the right side of your exhaust is meant to supply
exhaust gas through the small pipes (heatrisers) where it is blown out by the left side. "Cool"/"Slightly warm" on the LEFT side just doesn't cut it for good running. if both small diameter pipes are cool-ish to the touch - then your heat riser pipes are blocked. You can unblock them, but be prepared to get some quality filth inducing shed time. Took me most of a Saturday to use a drill with different lengths of clutch cable attached and reaming the manifold out. Got a welder? can speed it up if you drill two holes at where the heatriser pipes bend.

Miserable sod of a job.....

I might have been unclear of to where the cold is felt. I am attaching a picture with marked in red areas where I've measured the respective temperatures. I hope that helps clearing it out!
If that low of a temperatures are not normal under the cardy, what can I do to correct it? The manifold itself is hot/warm, but I didn't take reading of the temperature, but can do that if needed! Actually if you point me to different areas where I should take temperature readings, I can do that and post it on another picture!

[volkenstein]

Jovanybg,
              127F is too cold. Those pipes should be hotter. After I cleared mine - you could feel the heat radiating from them and touching would result in pain/blister. Now - you have the dreaded carby icing going on. Lee (68Autobug) and some UK bods wrap that manifold section with a heating blanket thingy. Search on thesamba for that malady/symptom.

HTH
Volkenstein