jackbombay
Top Post Dawg
GP usage is based on coolant temp once the engine is running.Kayakkermit said:
HOW TO tamper with the fuel temp sensor like KERMA
- Thread starter jackbombay
- Start date
TornadoRed
Top Post Dawg
- Joined
- Aug 3, 2003
- Location
- West Des Moines (formerly St Paul)
- TDI
- 2003 Jetta TDI wagon, silver; 2003 Jetta TDI wagon, indigo blue; 2003 Golf GL 5-spd, red (PARTED); 2003 Golf GLS 5-spd, indigo blue (SOLD); 2003 Jetta TDI wagon, Candy White (SOLD)
I think jackbombay is right. The air temp and fuel temp would not, can not, affect the operation of the glow plugs. No one is suggesting altering the coolant temp data -- that could be dangerous to more than just the glow plugs.Kayakkermit said:
Slave2school
Top Post Dawg
That is the point of this mod...Justler said:
I'm just trying to restate what I thought was the obvious... Some posts mentioned it not doing anything.
The ECU I would think assumes a minimum fuel temperature. I bet this would be most effective when combined with a 11mm or greather pump that really hikes up the fuel temp.
Good way to squeeze a little more timing out of the ALH =)
The ECU I would think assumes a minimum fuel temperature. I bet this would be most effective when combined with a 11mm or greather pump that really hikes up the fuel temp.
Good way to squeeze a little more timing out of the ALH =)
Slave2school
Top Post Dawg
Ah good stuff. I was hoping it wasn't another case of "too lazy to read the first post that explains it all" 
Seem to be having a rash of that disease lately.
Seem to be having a rash of that disease lately.
Greaseburger
Veteran Member
Has anyone done this on the 8 pin harness on the B4?
Maillemann
Veteran Member
Exactly what I'm wondering.Greaseburger said:
Anyone got a wiring diagram or data for that harness?
Greaseburger
Veteran Member
Well Lug_nut comes through again we looked it up in his Bently and found in the 8 pin harness on the B4 it's pin 4 and 7 that are the fuel temp sensor, I did the mod to mine using wire#7 on the connector and also one into the air temp sensor, Vagcom showed idle air temp to be 7.2c when it should have been 15.5c gotta run it around to double check the fuel temp but it looked good as well.
we looked it up in his Bently and found in the 8 pin harness on the B4 it's pin 4 and 7 that are the fuel temp sensor, I did the mod to mine using wire#7 on the connector and also one into the air temp sensor, Vagcom showed idle air temp to be 7.2c when it should have been 15.5c gotta run it around to double check the fuel temp but it looked good as well.
Maillemann
Veteran Member
Thanks a ton!
Just did this mod tonight using 2.2k resistors.
VAG-COM reports...
Before
Air: 28.8 C
Fuel: 50.4 C
After
Air: 7.2 C
Fuel: 14.7 C
Just did this mod tonight using 2.2k resistors.
VAG-COM reports...
Before
Air: 28.8 C
Fuel: 50.4 C
After
Air: 7.2 C
Fuel: 14.7 C
Link977
Veteran Member
OK, can someone tekk me where is the wire going to the Intake Air temp sensor located in a ALH engine? Pic will be appreciate.
Doc_Oc
Veteran Member
Link, you do it on the IP harness.
I just tried to do this on my 99.5 ALH Golf and it didn't work.
I first put the 2 res on 7 and 2 pins. The car wouldn't start. Like no fuel was injected. Than I took the IAT one out (2), the car would start but the glow plug light would flash and the CEL would be on. So I took them both out.
I don't have a VAG ready right now since I don't have my laptop anymore.
Any ideas why it isn't working?
I just tried to do this on my 99.5 ALH Golf and it didn't work.
I first put the 2 res on 7 and 2 pins. The car wouldn't start. Like no fuel was injected. Than I took the IAT one out (2), the car would start but the glow plug light would flash and the CEL would be on. So I took them both out.
I don't have a VAG ready right now since I don't have my laptop anymore.
Any ideas why it isn't working?
Joeviocoe
Veteran Member
- Joined
- Jun 11, 2007
- Location
- San Francisco, CA
- TDI
- 1999 VW Jetta TDI (Mk4) 1.9L ALH 5spd [VNT-17/22 Turbo, RC4, PP520 Nozzles]
I cant find out what exact model of Jetta that Skypup had. 1999, right but A3 or A4?
I want to do the IAT insulation mod or the FAT mod (resistor on the IAT and fuel temp sensors). Which one should I do? The pics of skypup's insulation on the IAT show a different location than mine. My IAT is on top of the intercooler but it still reports 86 degrees F (fuel temp is about the same) when the engine was off all night and real ambient is only 68 F. But the real problem is that the IAT reports 130 F and Fuel Temp reports 125 F when the engine is hot and running. Should I insulate or put a resistor or both?
Thanks
-joe
I want to do the IAT insulation mod or the FAT mod (resistor on the IAT and fuel temp sensors). Which one should I do? The pics of skypup's insulation on the IAT show a different location than mine. My IAT is on top of the intercooler but it still reports 86 degrees F (fuel temp is about the same) when the engine was off all night and real ambient is only 68 F. But the real problem is that the IAT reports 130 F and Fuel Temp reports 125 F when the engine is hot and running. Should I insulate or put a resistor or both?
Thanks
-joe
Joeviocoe
Veteran Member
- Joined
- Jun 11, 2007
- Location
- San Francisco, CA
- TDI
- 1999 VW Jetta TDI (Mk4) 1.9L ALH 5spd [VNT-17/22 Turbo, RC4, PP520 Nozzles]
How did you insulate the sensor? Just the sensor or also the pipe from the Intercooler to the EGR?KROUT said:
biopete
Veteran Member
I did this mod today and the fuel temp never got over 18C. I'm running WVO and before I had fuel temps at 99C. I stiill need to check the effects on timing and other things.
TornadoRed
Top Post Dawg
- Joined
- Aug 3, 2003
- Location
- West Des Moines (formerly St Paul)
- TDI
- 2003 Jetta TDI wagon, silver; 2003 Jetta TDI wagon, indigo blue; 2003 Golf GL 5-spd, red (PARTED); 2003 Golf GLS 5-spd, indigo blue (SOLD); 2003 Jetta TDI wagon, Candy White (SOLD)
Krout: if you are going to notice any difference, it will be during the hottest months and especially after a few hours of driving, when the fuel has reached its maximum temperature.
zorgman
Well-known member
just read this article and very intresting but one thing ive noticed on the chart was air temp 16.2deg now then got me thinking that so went out and checked mine it was reading 17.2 deg when the outside air was infact 11 deg and i thought back to the winter when it was 2 deg air temp but vagcom says air temp was 16 deg i know that coz i wrote it down. so rang a mate down south (im in the uk) and he checked his car and yes 17.2 deg.
my question is why? is the thermister somehow warming up and throwing this odd value as im stumped by it
my question is why? is the thermister somehow warming up and throwing this odd value as im stumped by it
Digital Corpus
Top Post Dawg
Been wondering
Hey guys. I've wanted to do this for a while but as far as I can tell, my harness differs. I saw one post about an 8 pin harness and teh wireing being different, but there was no resolution. I believe most of my wire colors do not match, then again I'm red/green color deficient so I cannot tell. Here is a pic of the harness:
Hey guys. I've wanted to do this for a while but as far as I can tell, my harness differs. I saw one post about an 8 pin harness and teh wireing being different, but there was no resolution. I believe most of my wire colors do not match, then again I'm red/green color deficient so I cannot tell. Here is a pic of the harness:
Last edited:
harry3
Veteran Member
- Joined
- Apr 2, 2010
- Location
- wisconsin
- TDI
- 2002 jetta tdi auto converted to 5 speed. 2003 tdi jetta 5 speed.
tampered with the fts today.
My 2002 jetta is converted to run on wvo. I bought it a month ago it was already converted. It would go into limp mode often, sometimes on diesel as well as wvo. It had no power after 3k rpm. I added one 2.2 reisiestor to yellow/blue wire (#7 on the plug). I just got back from a 40 mile pedel to the metel test drive. No limpe mode, smooth idel, power right up to red line. I was thinking the limp mode thing was one of many other posibility's and a'm tickeled pink it's running like a rocket!!! THANKS.
My 2002 jetta is converted to run on wvo. I bought it a month ago it was already converted. It would go into limp mode often, sometimes on diesel as well as wvo. It had no power after 3k rpm. I added one 2.2 reisiestor to yellow/blue wire (#7 on the plug). I just got back from a 40 mile pedel to the metel test drive. No limpe mode, smooth idel, power right up to red line. I was thinking the limp mode thing was one of many other posibility's and a'm tickeled pink it's running like a rocket!!! THANKS.
harry3
Veteran Member
- Joined
- Apr 2, 2010
- Location
- wisconsin
- TDI
- 2002 jetta tdi auto converted to 5 speed. 2003 tdi jetta 5 speed.
limp mode still haunts me
Went for a longer ride today and it went into limp mode a few times. No cel. It seems to hapen on longer trips. Never the lees the car seems to have more power than b-4 the fts mod.
Went for a longer ride today and it went into limp mode a few times. No cel. It seems to hapen on longer trips. Never the lees the car seems to have more power than b-4 the fts mod.
Victor Huge
Veteran Member
Harry, sounds like you need a new fuel temperature sensor
robnitro
Veteran Member
No, you don't need a new temp sensor.
The problem is if you do the FUEL temp mod without the IAT mod, the ECU freaks out. Try a 1k Ohm resistor on the IAT. I forget which wire it is as I removed mine. Be sure it is the temp wire only, not the feed wire or ground wire (which will screw up pressure readings).
The problem is if you do the FUEL temp mod without the IAT mod, the ECU freaks out. Try a 1k Ohm resistor on the IAT. I forget which wire it is as I removed mine. Be sure it is the temp wire only, not the feed wire or ground wire (which will screw up pressure readings).
robnitro
Veteran Member
It doesn't matter as the current flowing is in the milliamps, which would never get to the point of even 1/4 watt! I've since removed the resistors as I got an ebay FMIC and a cheap tranny cooler as a fuel cooler.