Rev after start & Long crank

RoundHouse

Veteran Member
Joined
May 23, 2001
Location
Ga USA
A few weeks ago our '98 NB started revving up a little after it was cranked.

Was not a long start, was easy start but revved a little after starting.
Start was almost instant, maybe 1/2 second crank time.



Now it takes 1 or 1.5 , sometimes 2 seconds of crank time to start.

Happens on the first start of the day and on rot restarts, temp of the engine doesnt seem to matter.

What should I check first.?

Does the 1998 model have a lift pump?
 
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jettawreck

Top Post Dawg
Joined
Aug 2, 2004
Location
Northern Minnesota-55744
TDI
2001 Jetta and 2003 Jetta
Mine was doing something similar after I installed the CAT fuel filter conversion. I hadn't replaced the O-rings on the "T" fitting on the filter's top adapter plate when I installed it. Replaced the "T" fittings O-rings and all seems good now. Decided to do it after it sat 3 or 4 days and had the first "long" cranking start ever in warm weather. The clear fuel line was empty, so enough of an air leak the fuel would slide back into the filter after an extended time. Never leaked any fuel-just get some air vent thru, I guess. Easy place to start anyways.
 

HopefulFred

Veteran Member
Joined
Sep 5, 2002
Location
Atlanta, GA
TDI
Golf, 2006, Indigo Blue
Your 98 doesn't have a lift pump.

Air in the fuel line would be a good place to start, but I don't think that condition explains all of your symptoms. Can you be more specific about "revving up a little after it was cranked?"

Do you notice smoke when it starts? What color?
 

RoundHouse

Veteran Member
Joined
May 23, 2001
Location
Ga USA
HopefulFred said:
Your 98 doesn't have a lift pump.

Air in the fuel line would be a good place to start, but I don't think that condition explains all of your symptoms. Can you be more specific about "revving up a little after it was cranked?"

Do you notice smoke when it starts? What color?
It would start after a short, normal crank time, them rev to 1200 or so for a few seconds, the idle normal. No noticeable smoke.

No longer does that, now just long crank time, then regular idle.

Switching it on and waiting for the glow plugs to go off doesnt change anything, and a hot restart doesnt change anything, so it seems to be a fuel leakdown issue.

Seems like the fuel is leaking back from the injectors back past the injector pump?
 

79TA7.6

Veteran Member
Joined
May 8, 2006
Location
Live: Wilbur/Creston; Work: Moses Lake Washington
TDI
2003 TDI Jetta, 2002 TDI Golf, 2005 TDI Golf
My 2003 seems to rev up after it first starts like yours did, but only occasionally. It acts as though I am trying to start it like a carbruated engine. It revs to maybe 1200 or 1300 rpm but for just a second. Not even long enouh for the tach to come online and show this, but you can hear it. It does it cold or hot, but only when it wants to. If I go out to start it now, it might do it, but it might not. At first I was thinking that maybe it is getting a taste of oil or something, but I am not sure. I pulled the lower line off the boost cooler and there was a little oil in it, not too much.
 

jettawreck

Top Post Dawg
Joined
Aug 2, 2004
Location
Northern Minnesota-55744
TDI
2001 Jetta and 2003 Jetta
I had the second (give or take a bit) of "higher rev than idle" before I replaced said O-rings, which was causing air in the fuel line. Made a little more smoke on start-up then, too, Doesn't do it anymore, so I assume that was the issue there. Your results can and will vary.
Was much like when starting at -0F, only then the higher idle continues a while longer depending on how cold it is.
 

greenskeeper

Top Post Dawg
Joined
Mar 10, 2003
Location
USA
TDI
1998 Jetta TDI
fuel cutoff valve o-ring? Easy to check just pull the valve (1 wire going to it on the IP) and see if the o-ring needs to be re-seated.
 

RoundHouse

Veteran Member
Joined
May 23, 2001
Location
Ga USA
greenskeeper said:
fuel cutoff valve o-ring? Easy to check just pull the valve (1 wire going to it on the IP) and see if the o-ring needs to be re-seated.
Is this O ring some weird size I can only get at a stealership, or is it common hardware store item?
 

greenskeeper

Top Post Dawg
Joined
Mar 10, 2003
Location
USA
TDI
1998 Jetta TDI
most likely it just needs to be reseated on the valve (theres a groove to hold it in place). If somehow the o-ring is trashed I would think it is a common size, otherwise you'd have to get a new fuel shutoff solenoid from the stealer.
 

Drivbiwire

Zehntes Jahr der Veteran
Joined
Oct 13, 1998
Location
Boise, Idaho
TDI
2013 Passat TDI, Newmar Ventana 8.3L ISC 3945, 2016 E250 BT, 2000 Jetta TDI
RoundHouse said:
A few weeks ago our '98 NB started revving up a little after it was cranked.

Was not a long start, was easy start but revved a little after starting.
Start was almost instant, maybe 1/2 second crank time.



Now it takes 1 or 1.5 , sometimes 2 seconds of crank time to start.

Happens on the first start of the day and on rot restarts, temp of the engine doesnt seem to matter.

What should I check first.?

Does the 1998 model have a lift pump?
This is a CLASSIC easy fix!

Dealers replace injection pumps because of this issue {but you won't}.

The problem is caused by a swollen o-ring on the Fuel Shut-off selenoid. The o-ring binds up the shut-off plunger causing the extended cranking. The ECU does not see the engine fire after the first two Piston TDC's at the crank sensor. The ECU at TDC #3 increases fuel IQ THEN the fuel selenoid unbinds due to increasing fuel pressure (associated to engine cranking rpm) and the engine fires and revs up due to the last request by the ECU to increase fuel quantity!

Here is what you do, remove the fuel shut-off selenoid on the pump, replace the o-ring, re-install the selenoid and the problem goes away.

Dealers are not trained to trouble shoot the pumps so they throw a new pump at the problem hence their bad reputation.

Cost of repair, about $2.00

The o-ring is part #5 under/around the fuel shut-off selenoid:



GENUINE PART
SEAL
Diesel Injection Pump Soleniod Valve Seal

(OEM part number: 068-130-139)

List Price: $2.22 :: Impex Price: $1.92

DB
 

Bopper

Veteran Member
Joined
Oct 11, 2004
Location
New Jersey, Exit 165
TDI
98 Jetta GLS Tornado Red
I don't have a great deal of experience wrenching. I start to question taking other systems apart, risking damaging them in the removal in order to get what I want.
I can't figure how to remove the sensor without messing with the lines around it.
Any advise or experince would be appreciated.
Thanks
 

Drivbiwire

Zehntes Jahr der Veteran
Joined
Oct 13, 1998
Location
Boise, Idaho
TDI
2013 Passat TDI, Newmar Ventana 8.3L ISC 3945, 2016 E250 BT, 2000 Jetta TDI
Take it to a local TDI guru, It's better to not mess with something your not comfortable with than to damage a very expensive pump.

DB
 

RoundHouse

Veteran Member
Joined
May 23, 2001
Location
Ga USA
Ok, new O ring solved revving.

Now is intermittently hard to start, thought was defective battery, changed battery, wiped out radio, local stealership refuses to help get code.....
Sounds just like battery is half dead, starter turns over slowly, and your instinct is to give up, but if you just keep holding the key, it will start up.

Very odd, maybe loose wiring?
 

HopefulFred

Veteran Member
Joined
Sep 5, 2002
Location
Atlanta, GA
TDI
Golf, 2006, Indigo Blue
Does sound like it could be a loose or corroded connection somewhere - like either of the cables or the connection at the starter. Could also be that the battery is not adequate; what battery did you put in it? (If you didn't get a dealer battery, call and price one. Then have them put it in and unlock your radio at the same time. ;) )
 

Drivbiwire

Zehntes Jahr der Veteran
Joined
Oct 13, 1998
Location
Boise, Idaho
TDI
2013 Passat TDI, Newmar Ventana 8.3L ISC 3945, 2016 E250 BT, 2000 Jetta TDI
If your battery is 4 years or older...time for a new one.

Try to get at least an 80Ah rated battery from the dealer or an AGM with at least a 72Ah rating (most are between 80-95Ah that will fit on our battery area).

DB
 

RoundHouse

Veteran Member
Joined
May 23, 2001
Location
Ga USA
Bought a new battery at the stealership.


They never mentioned that removing it would lock up the radio, and refused to call VWoA to get the code.
 
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