Random rev in neutral, engine shuts off?

jackfolstam

Veteran Member
Joined
Oct 14, 2016
Location
CA
TDI
MkI Rabbit ALH swap
1999.5 Jetta ALH
Hey guys what do you think about this one:
I drove the car 40 miles, 5 miles city 33 miles highway. 2 miles city, and had a problem in the last mile. Twice at stop signs when shifting from first to second, the RPMs revved during the shift and the exhaust blew a cloud of smoke. I thought at first it could have been driver error. Then driving a mile to lunch and back no problems, but going to dinner 2 miles out same thing once but when coming to a stop, a random rev and a cloud of smoke. Then, when driving the 40 miles home, it did the thing again at mile 2 during the 1 2 shift but I kept the clutch pushed in instead of continuing in second, and the engine died. It did it again when trying to pull away; I played with the pedal and could keep it running by blipping the throttle but it died when I didn't touch it. I fired it back up and took it real easy with the 1 2 shift and made it back home with no other issues.

Recent changes:
Last weekend changed the drippy uro parts PCV tube out with a diverter valve soft hose I got from a Mk1 TT in the junkyard, I was thinking the original pcv valve is plastic so it does not collapse and the rubber one is somehow causing the problem. So I put the leaky tube back in and we'll see. I think the only way a collapsing pcv valve, if that can actually happen, is if during deceleration or RPM drop the engine pulls vacuum on that and it closes, but then what, why would it die or why would it continue to run if I touched the throttle, and then die still? I've had a catch can clog completely and then everything run fine, except have a blown front main seal/blown turbo seals to vent the pressure. And why not the same issues during any other shift?
I have a 270k mile motor and have had a surging issue at 1350rpm since I got the car with 200k and just have dealt with it but recently thought about fixing it. Two weeks ago I changed out the dbw pedal with a 100k mile jy unit with no effect. If putting back the old pcv tube doesn't fix it I'll also put back the old pedal.
3 weeks ago I changed the IQ from 2.0 to 5.0 to see if it would change the surging, it did not.
At the same time I checked the vcds timing and it was right in the middle.

Otherwise, it's a new problem. I took off the timing belt cover and at first glance all is correct. I mean it's a specific problem, even though I haven't found all of the scenarios that which causes it, because I'm worried I will damage something while testing,it seem like there are few things that would cause such a specific problem of the engine dying during a 1 2 shift that I can rule out a lot of things such as a bad MAF, crank position sensor, etc. To think even more specifically, maybe a there was physically something hitting the dbw pedal but I've been wearing the same shoes for a long time and there is nothing new in the driver footwell to interfere with the pedal.
 

jackfolstam

Veteran Member
Joined
Oct 14, 2016
Location
CA
TDI
MkI Rabbit ALH swap
Today it still did the rev and die with the old plastic pcv hose. It also revved and died while braking a little hard in neutral from around 25mph. I will change the dbw pedal back to the original tonight but I'm thinking maybe it's got to do with an accel to a decel, like something is swinging or sloshing. Such as the wire harness swinging, the chip socketed chip banging around, the fuel or oil sloshing etc. It seems to do it regardless of shift rpm, like shift low or high in rpm doesn't matter.
 

jackfolstam

Veteran Member
Joined
Oct 14, 2016
Location
CA
TDI
MkI Rabbit ALH swap
P1619, it's been there for a few months. Swapped relays, new glow plugs, fixed the harness on the obvious broken spot but it's still there. Curiously gp #1 had soot up past the seat but stopped at the threads.

It didn't do the rev thing on the drive home last night, and I filled the fuel tank 2 miles into the trip, which was down to 1.5 gallons. And it didn't do the rev thing this morning. So I had a problem a few years ago with low power after running the tank nearly empty and some of that green diesel kleen fixed it up with immediate results. So I haven't added that to the tank for a few years so I'll try and get some tonight on the way home.
 

JETaah

Vendor , w/Business number
Joined
Jan 18, 2001
Location
mi 48836
TDI
96 B4V, 1999.5 jettaIV,2005 BEW Beetle
P1619, it's been there for a few months. Swapped relays, new glow plugs, fixed the harness on the obvious broken spot but it's still there. Curiously gp #1 had soot up past the seat but stopped at the threads.

It didn't do the rev thing on the drive home last night, and I filled the fuel tank 2 miles into the trip, which was down to 1.5 gallons. And it didn't do the rev thing this morning. So I had a problem a few years ago with low power after running the tank nearly empty and some of that green diesel kleen fixed it up with immediate results. So I haven't added that to the tank for a few years so I'll try and get some tonight on the way home.
Nothing to do with the revving or stalling but...
GP soot should stop at the seat. No curiosity there...it is not seated properly. If you can not screw the GP in to the seat with/or little more than finger-tight effort then the threads are clogged with soot or corrosion. A gun barrel bronze brush on the end of one of the extensions in a drill is what I use along with antiseize on the threads of the glow plug. Be careful not to run the drill in reverse as the brush may unscrew from the extension down into the bore.
 

jmodge

Veteran Member
Joined
Jun 18, 2015
Location
Greenville, MI
TDI
2001 alh Jetta, RC2 w/.205's 5speed daily summer commuter and 2000 alh Jetta 5spd swap, 2" lift, hitch, stage 3 TDtuning w/.216's winter cruiser, 1996 Tacoma ALh
Have you checked your complete intake tract, including snow screen, air filter, and MAF right down to the turbo?
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
Like that^^
Might also be worth opening up the fuel tank, look for debris.
I drove a 99.5 for years. Those were run a while on LSD, today we have ULSD, a bit of improvement. Mine wore out the IP internals in less than 100k miles. So if your pump is original it may be wore out. And if the intake has never been cleaned that could cause issue (retriction) as well.
 

jackfolstam

Veteran Member
Joined
Oct 14, 2016
Location
CA
TDI
MkI Rabbit ALH swap
Thanks for all the tips.

I changed out the stock intake tubing for a diy eBay parts old man intake a while ago. I had the upper half off a month ago to take a good look at all the vacuum lines; the asv seems to be closing for only a split second rather than staying closed and the engine was and still is shuddering to a halt. Anyway, I could take the lower half off albeit a pain but that's one more thing to cross off the list.

The ip is not original; I got an 11mm from the junkyard that's stamped with Czech Republic on it, a reman or something. I want to say it's newer than the OEM ones.

I understand about the gp seat, thanks, I did try to clean up the seat for a better seal but I haven't pulled it back out to check.

The issue didn't occur today so I think I will let the tank get low and see if it comes back, without adding the Power Service diesel tank cleaner stuff just yet.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
The ASV will momentarily close when the car is turned off. Issue we see with these is when it sticks closed.
 

jackfolstam

Veteran Member
Joined
Oct 14, 2016
Location
CA
TDI
MkI Rabbit ALH swap
Yesterday at somewhere above quarter tank and below half tank it did the throttle blip again between the 1 and 2 shift. It again felt like driver error it seemed random but it was the same conditions as before. I feel like if the pump sucked up a bubble of air it would just keep running until the filter was empty or it got more fuel and it would fill the filter. Like a bubble of air wouldn't get to the fuel pump (with my theory of sloshing fuel being the culprit). But if it were a clog that's moving around, I could test by idling the engine and pinching the fuel line for a second and see if it has the same rev effect.

I think I will change the fuel filter as well as pour in the power service this next tank.


If I hold the asv closed, the engine shuts off real smooth and quick. I took a video of it when keying off and it flips closed then immediately opens, it doesn't stay closed for any period of time and the engine shudders. Is that the normal operation? I looked inside the intake and its not chunky, just had a film of stuff all over so it operates smoothly, and applying vacuum it closes and stays closed.

I checked the gp and the soot was up to but not on the threads. It spun out and in smoothly, but I didn't feel like cleaning the seat right then.
 

muzy

Veteran Member
Joined
Aug 19, 2012
Location
Southern Alberta
TDI
02 jetta TDI
Well thats kinda funny ya know.
I it were me, I would have quit the blip thing, but that's me and it shouldn't do that.
Is your vacuum reservoir still in the system?
Cheers
 

jackfolstam

Veteran Member
Joined
Oct 14, 2016
Location
CA
TDI
MkI Rabbit ALH swap
I got the tank down to 1 gallon and it didn't do the thing. I filled it up without the power service or filter but today I will do those things regardless. I meant to look in every part of the omi but I just couldn't find the time this weekend. I could also try and drain the water out of the fuel filter since I never do that, because, I have never found water in the filter.
I was thinking for a while now my turbo seals are on the way out; it makes a puff of white smoke on start up, it has a moderate amount of oil on the charge pipes, and it consumes almost a quart per 5,000 miles. So what if it were a tiny run away due to the oil? Well then why does it only rev between the 1 2 shift or slowing quickly from 25mph?

The vacuum system is the stock routing. I think I noticed that if I shut it off with my foot off the brake it shuts down quickly. It's that I always hold the brake hen keying off so this week I have to think about it and take my foot off the brake first then key off to find out.
 

muzy

Veteran Member
Joined
Aug 19, 2012
Location
Southern Alberta
TDI
02 jetta TDI
I reread your first post. Thought you were doing the blip, but now I see it is doing it on its own. Weird.
cheers
 

jackfolstam

Veteran Member
Joined
Oct 14, 2016
Location
CA
TDI
MkI Rabbit ALH swap
I put some Power Service diesel cleaner in the tank and it seems to have fixed it, didn't change the fuel filter.

Actually what I think fixed it was moving the iq back and forth a few times.
 
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