Hard to start when hot issue.....

Bayou_Flyer

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Joined
Nov 8, 2000
Location
Mississippi Gulf Coast
TDI
2010 Golf 4Door 6M
Pheww, I finally made it through all 20 pages! What a read.

Looks like my 99.5 Golf and I are in good company. I've been dealing with this problem for a few years now, but starting the engine has become more difficult and lengthy after a fill-up. It does take a few seconds to start when warm, but it's noticeably faster in cooler temps (which isn't that often on the Gulf Coast). Any ideas?
 

ta79pr

Veteran Member
Joined
Sep 18, 2005
Location
Lexington, SC
TDI
02 TTQ (BEW)
hmm, i wish the guy's english was a little better.
when he says "heat/smoke relay" is he referring to a label or a description?
one of the gurus should call this cat.
 

whitedog

Veteran Member
Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
Hammond mod? Is that the one where you insert a piano in place of the dashboard?

Hmmm Maybe you mean "Hammer Mod?" Search for that and I'll bet you have better luck.
 

gunns112

Veteran Member
Joined
Sep 5, 2006
Location
seattle WA.
TDI
99.5 Jetta TDI
hard start when hot

I heard that the fix is to have your fuel pump worked on. there is a valve that is bad, this auto mechanic can fix the problem. www.zahntechauto.com check them out. I have a 1999.5 with same problem and going to try it. One of the only WV mechanic you can trust.
 

MOGolf

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underneath something
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2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
whitedog said:
Hammond mod? Is that the one where you insert a piano in place of the dashboard?
That would require 88 SKCs (secret key codes). ;)
 

whitedog

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Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
MOGolf said:
That would require 88 SKCs (secret key codes). ;)
And I have trouble with just one SKC. I think I'll pass.

So, has anyone had any luck with this when rebuilding the pump? There is supposed to be a GTG in Portland where DFIS rebuilds a pump for everyone, so maybe we can learn something and get some pictures of what they say is going on.
 

RaysirX

Well-known member
Joined
Mar 23, 2006
Location
Northern NJ
TDI
1999.5 Jetta
Progress

There must be some truth to the ECM waiting for the cranking speed to reach a predetermined rpm, before fuel is injected.

A while back I posted that a new Optima battery improved warm start time on my 1999.5 Jetta. Well the problem gradually resurfaced. Recently my original starter (130,000 miles) began to hang up/moan. I followed the forum's directions to remove/clean/GREASE the starter's nose cone gears.

Well It has been 3 weeks and so far it is like new. Cranking time is in the 1 second range, with an occasional 2 seconds.

When I opened my starter I did not detect any grease on the 3 gears that surround the main gear.

My theory is that either the starter bolts to the block and or 12v supply cable were dirty or corroded and by removing the starter cleaned the threads/contaxts up.

Or

Re-greasing the starter increased cranking RPM.

As you may recall other posters have remarked that a new starter cured their problems.;)
 

whitedog

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Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
Ray, this makes me want to try just R&R the starter, installing hte same one, untouched. Just to see if the connections are the problem.

Unfortunatley I don't have a starting problem.
 

MCathcart

Veteran Member
Joined
Apr 18, 2001
Location
North Myrtle Beach, SC
TDI
2003 Jetta
We've been there before (and I've seen it on at least 5 times on different cars, Two I currently own.) If you can spin it Faster, yes it will decrease starting time. So it will "seem" the problem is solved. OK, do the starter (R&R) :rolleyes: (and replace the battery cables and battery) now when the engine is HOT unplug the Coolant Sensor and see what happens?:D The Hammond Mod is fairly easy, I've suggested using a Relay that's wired to the Starter, therefore no button is needed.
 

spine911

Veteran Member
Joined
Dec 29, 2004
Location
orange county,ca
TDI
beetle, 1998,black
MCathcart said:
We've been there before (and I've seen it on at least 5 times on different cars, Two I currently own.) If you can spin it Faster, yes it will decrease starting time. So it will "seem" the problem is solved. OK, do the starter (R&R) :rolleyes: (and replace the battery cables and battery) now when the engine is HOT unplug the Coolant Sensor and see what happens?:D The Hammond Mod is fairly easy, I've suggested using a Relay that's wired to the Starter, therefore no button is needed.
MCathcart,
Do you have specific instructions (parts and install procedure)on how to place a Relay with the Hammond Mod?

THANKS!
 

MCathcart

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Joined
Apr 18, 2001
Location
North Myrtle Beach, SC
TDI
2003 Jetta
I'll see if I can't draw it up and post it later today. It's fairly simple. One set of contacts on the 12V DC relay will be wired just like Mr. Hammon says to operate the relay, the "0" or "-" will go to the ground and the "+" or "Positive" will connect to the starter. I'll do my best to get it posted by 10:00 pm Eastern.

Mike
 

MCathcart

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Joined
Apr 18, 2001
Location
North Myrtle Beach, SC
TDI
2003 Jetta
Hammond Mod W/Relay

I'm going to post Mr. Hamman's instructions on what wire to cut.

"First, go to the back side of the engine where the temp sensor is and remove it for easy access. Find the #3 conductor which is on the upper right of the installed sensor is viewed from the driver's seat. After removing about 2 inches of wrap from around the wires, cut the conductor from #3 about 1 inch from the plug. Strip both ends, and solder in a 18-22 guage two conductor wire." One Wire Goes To The Comman and the Second To The NC (normally Closed Contact)

Part numbers are;

Radio shack 275-206 12VDC/3A DPDT Relay w/Socket (Socket is not really needed)
Radio shack 271-1335 1/4 watt 10,000 ohm resistor

I would solder the wires directly to the relay and Heat Shrink them (but soldering them to the socket is not a problem). The 12V+ wire from the Relay should connect to the small pole on your Starter Solenoid (from Ignition Switch. (I only drew two wires from the Temp Sensor.)

OPERATION
As soon as the Starter gets the Signal from the Ignition Switch, the Relay Opens (because it get's 12V to the coil) and See's the Resistor and the Computer says "Hey I'm COLD" and puts more fuel to the engine. Result is Much Faster Cranking. Once the Starter is Released (placed in the "RUN" position the Relay Closes and the engine see's the Temp Sensor. Mount the relay under the hood somewhere. Be sure to tape or use wire loom on the wires. I personally like Ice Cube Relays but any 12VDC douple throw relay will work. Only one side is used on Radio Shack.

 
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spine911

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Joined
Dec 29, 2004
Location
orange county,ca
TDI
beetle, 1998,black
Mike,

Thanks for the information, very straightforward.
Just for clarification, the 12v Relay wire should be connected to the "small pole of the starter solenoid"... Are you referring to the (+)/red pole of the starter, or the (+) pole of the Ignition Switch/Key Tumbler?

Thanks
 

MCathcart

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Joined
Apr 18, 2001
Location
North Myrtle Beach, SC
TDI
2003 Jetta
spline911, you are correct... Connect the (+) Relay wire to the Small Pole on the starter.

(and not to the Larger pole. The Larger Pole connects to the Battery, the would tell the Computer "I'm Cold" all the time.)

Mike
 

spine911

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Joined
Dec 29, 2004
Location
orange county,ca
TDI
beetle, 1998,black
MCathcart said:
spline911, you are correct... Connect the (+) Relay wire to the Small Pole on the starter.

(and not to the Larger pole. The Larger Pole connects to the Battery, the would tell the Computer "I'm Cold" all the time.)

Mike
Mike,
What would happen if the relay fails later on? No start, Hard start??
How reliable is this set-up?
Im more inclined to do this variation of the Hamman Mod with the relay because it doesnt have the switch.
Thanks!
 

MCathcart

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Joined
Apr 18, 2001
Location
North Myrtle Beach, SC
TDI
2003 Jetta
If the relay fails, it will return to the old starting pattern. In other words, it won't see the resistor. Since there's no load the relay should last a long time unless it gets wet. The only time the relay will open (activated) is when the Starter is turning.
 

AnJettica

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Joined
Oct 15, 2006
Location
Windsor, CT
TDI
2011 Acura MDX, 1999.5 Jetta Sedan
My 1999.5 Jetta has the same problem. Long hard start when warm, starts right up when cold. I read the thread and tried a few of the sugestion. Let me know if there is anything else I can try. Thanks
Angelica
 

drkblujetta

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Joined
Jan 31, 2007
Location
Venus
TDI
2011 Audi A4 ALH TDI
Did anyone replace a pump and fix this problem........

My 99.5 has had this issue since day one before any mods etc........
Unplugging the Coolant sensor does the trick........but we have put
the car on VAGCOM and the pump seems to be the issue here......

Thanks........:p
 
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wakeboarder_shawn

Veteran Member
Joined
May 23, 2006
Location
Thornton, ON, Canada
TDI
2009 Jetta TDI Highline
drkblujetta said:
Did anyone replace a pump and fix this problem........

My 99.5 has had this issue since day one before any mods etc........
Unplugging the Coolant sensor does the trick........but we have put
the car on VAGCOM and the pump seems to be the issue here......

Thanks........:p
I had this problem also until one day my injection pump died. I put in an 11mm pump from a 2000, no more hard to start when hot issue
 

MCathcart

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Joined
Apr 18, 2001
Location
North Myrtle Beach, SC
TDI
2003 Jetta
drkblujetta said:
Did anyone replace a pump and fix this problem........

My 99.5 has had this issue since day one before any mods etc........
Unplugging the Coolant sensor does the trick........but we have put
the car on VAGCOM and the pump seems to be the issue here......

Thanks........:p

Yep, just like Shawn says. I think there's been at least three people who posted a rebuild or new pump took care of the problem. With this being said, I tried adding a 12psi electric pump for a booster and it made no difference. This is one problem that I've tried to solve for at least 3 years. I still wish someone would come up with an "tighten the left rear lug nuts" answer. So far the Hammond mod is the only thing that will make two of my Tdi's crank instantly while hot. (Yes, I've done the battery and starter R&R.)

What clues did the VagCom give you to lead you to the pump?

Mike
 

STRANGETDI

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Sep 20, 2001
Location
East Hampton, CT
TDI
2013 Audi A3 S-Line Premium Plus Quattro - APR Stage II
This could be a dumb question or theory, but do you think replacing the vacuum hoses could do something? Does vacuum have any effect on warm or hot starts?
 

spine911

Veteran Member
Joined
Dec 29, 2004
Location
orange county,ca
TDI
beetle, 1998,black
Hamman Mod with Relay

Guys,
Im very happy to share to all that the Hamman Mod with relay(No switch) works like a charm. Ive been road testing this mod for 3 weeks now and it works well. Pls. take note that different relays may have different positional connection (NO,NC, Common)configurations from MCathcart's diagram. MAKE SURE you analyze your relays connections and follow MCathcart's directions. My Relay NO(normally open) is in between the NC(normally closed) and the Common.

Thanks MCathcart!:D



MCathcart said:
I'm going to post Mr. Hammond's instructions on what wire to cut.

"First, go to the back side of the engine where the temp sensor is and remove it for easy access. Find the #3 conductor which is on the upper right of the installed sensor is viewed from the driver's seat. After removing about 2 inches of wrap from around the wires, cut the conductor from #3 about 1 inch from the plug. Strip both ends, and solder in a 18-22 guage two conductor wire." One Wire Goes To The Comman and the Second To The NC (normally Closed Contact)

Part numbers are;

Radio shack 275-206 12VDC/3A DPDT Relay w/Socket (Socket is not really needed)
Radio shack 271-1335 1/4 watt 10,000 ohm resistor

I would solder the wires directly to the relay and Heat Shrink them (but soldering them to the socket is not a problem). The 12V+ wire from the Relay should connect to the small pole on your Starter Solenoid (from Ignition Switch. (I only drew two wires from the Temp Sensor.)

OPERATION
As soon as the Starter gets the Signal from the Ignition Switch, the Relay Opens (because it get's 12V to the coil) and See's the Resistor and the Computer says "Hey I'm COLD" and puts more fuel to the engine. Result is Much Faster Cranking. Once the Starter is Released (placed in the "RUN" position the Relay Closes and the engine see's the Temp Sensor. Mount the relay under the hood somewhere. Be sure to tape or use wire loom on the wires. I personally like Ice Cube Relays but any 12VDC douple throw relay will work. Only one side is used on Radio Shack.

 

BoostdJetta

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Joined
Apr 27, 2004
Location
SE Michigan
TDI
99.5 Jetta TDI 5spd
Did you get the same part number from Radio Shack? I soldered the resistor to the relay but haven't taken the time to find the temperature sensor though.

I highly doubt vacuum hoses have anything to do with the issue.
 

spine911

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Location
orange county,ca
TDI
beetle, 1998,black
Yes, I got the relay from Radio Shack ($9.00 clear-ice cube type which made it easier to visually verify the position of the NO,NC,Common).
Once you find the Temp. Sensor, you have to splice the #3 connector/wire(Blue/Brwn color).


BoostdJetta said:
Did you get the same part number from Radio Shack? I soldered the resistor to the relay but haven't taken the time to find the temperature sensor though.

I highly doubt vacuum hoses have anything to do with the issue.
 
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No Exit

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Mar 29, 2006
Location
Herndon, VA
Our 99.5 had a hard start problem... Jeff swapped out the ecu for one that he had presoldered for rc2/3 and set it to rc2. Instant fix. I dont know if it was the ecu itself or the software. Either way, the problem went away immediately. Nothing else was changed, added, or deleted
 

STRANGETDI

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Location
East Hampton, CT
TDI
2013 Audi A3 S-Line Premium Plus Quattro - APR Stage II
No Exit said:
Our 99.5 had a hard start problem... Jeff swapped out the ecu for one that he had presoldered for rc2/3 and set it to rc2. Instant fix. I dont know if it was the ecu itself or the software. Either way, the problem went away immediately. Nothing else was changed, added, or deleted
Was it a european ECU? Wonder what is in RC programming that makes it work, as my Upsoluted ECU for 5 years hasn't solved it.
 
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