www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2016 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You

Order your TDIClub merchandise and help support TDIClub


Go Back   TDIClub Forums > TDI Model Specific Discussions Areas > VW B5 Passat TDIs

VW B5 Passat TDIs This is a general discussion about B5 Passat(>98 (2004-2005 in North America)). Non TDI related postings will be moved or removed.

Reply
 
Thread Tools
Old March 23rd, 2020, 15:43   #1
Runninwild
Veteran Member
 
Join Date: Jul 2018
Location: vancouver
Default Fuel priming issues?

Hey guys. I swapped a bhw into my Tacoma recently. I haven't put many miles on the swap yet but I've developed what I think is a priming issue. I have hard starting when the engine has been sitting for a while.

I have a cheap low pressure inline primer pump originally in my engine bay. When I first completed the swap I didn't have any starting or running issues. I eventually started having problems losing prime over night. I ended up installing a check valve on each fuel line which seemed like it helped. I didn't drive the truck but fired it up every night when I got home from work and it always started first crank. On the Friday night I took the truck to home Depot, about 1km out of the parking lot it died at an intersection and was really hard to start. Eventually got it going and took off. A few more km down the road and the truck started sputtering like it was running out of fuel. I pulled into a gas station and the truck died. Filled 45l (half of my 90l tank) when diesel started to pour out of the fill neck. Got the truck going again and started heading home. For the first couple km the truck was sputtering like it was running out of fuel but eventually smoothed out and went back to normal. The next morning I relocated my primer pump and fuel delivery check valve to directly infront of my fuel tank. Put about 70km on the truck this weekend with multiple starts and stops. A couple of times it would crank over a bit before firing but nothing too crazy. This morning I went to take the truck to work and it wouldn't start. Was cranking on it for about a minute and I got it to cough once then cranked like another minute before giving up.

Does this most likely sound like my tandem pump? Fuel tank and all my lines are new and I can't find any cracks or external leaks in any of the hoses. If it is the tandem pump is there a way to fix it or does it need to be fully replaced? Engine has about 280,000km on it if that makes a difference. Haven't noticed any increase in oil level or my oil smelling like diesel in the limited mileage I've put on since the swap.
Runninwild is offline   Reply With Quote
Old March 23rd, 2020, 16:16   #2
Lotawood
Newbie
 
Join Date: Oct 2017
Location: montana
Default

Is there any -in the fuel tank- pump? Like the Passat had.
Lotawood is offline   Reply With Quote
Old March 23rd, 2020, 21:12   #3
Runninwild
Veteran Member
 
Join Date: Jul 2018
Location: vancouver
Default

No just my primer pump. But right after the swap the motor ran fine even with the primer pump off and had no issues loosing prime at the beginning. Hard starting is fairly new and seems to be getting worse.

When I got home from work I tried to start it and it fired first crank. I ran it for 30 seconds or so then turned it off and let it sit for a minute and it was really hard to start. I pulled the t out of the fuel filter and ran the primer pump until fuel started spewing out. Put the t back in and it fired up after a bit of cranking. Turned it off and it started right away. Turned it off and let it sit for about a minute and it wouldn't start again. I'm really at a loss for this. My primer pump makes a different tone when it's pumping air or fluid so it's fairly easy to tell when the lines are primed (pump gets a lot quieter). I'm not even sure it's a priming issue anymore at this point. Only codes I'm getting is VSS and I had a pending code for thermostat as well. It was like 10c so glowplugs shouldn't be an issue even if they aren't working. I'm like completely at a loss for this. I also checked the timing belt to make sure the cam pulley was tight.

Ecu has a stage 2 Malone tune and I'm only running crank, cam, fuel temp, coolant map\iac and n75 sensors
Runninwild is offline   Reply With Quote
Old March 23rd, 2020, 21:34   #4
Runninwild
Veteran Member
 
Join Date: Jul 2018
Location: vancouver
Default

should also mention I changed the timing belt and did the balance shaft delete when I had the engine on a stand. When I first had the car running it seemed like it shook a lot at idle and was pretty loud. I've noticed lately its vibrating a lot less and isn't as loud at idle anymore. I also don't know if im getting used to driving it but it doesn't seem like it pulls as hard as it first did. I don't know If its connected but maybe it has something to do with it? I don't have vcds so cam timing was never set properly but had physical timing double checked with locks. I checked the 3 bolts on the cam and they all felt tight by hand so I don't think its moved at all.
Runninwild is offline   Reply With Quote
Old March 24th, 2020, 02:43   #5
afarfalla
Veteran Member
 
afarfalla's Avatar
 
Join Date: Nov 2006
Location: sugar land tx
Default

your a tooth off
afarfalla is offline   Reply With Quote
Old March 24th, 2020, 06:42   #6
Runninwild
Veteran Member
 
Join Date: Jul 2018
Location: vancouver
Default

Quote:
Originally Posted by afarfalla View Post
your a tooth off

Wouldn't that be more of a consistent starting issue. This kinda started slow and has gotten bad pretty quick but it's still not 100% cosistent
Runninwild is offline   Reply With Quote
Old March 24th, 2020, 18:11   #7
Runninwild
Veteran Member
 
Join Date: Jul 2018
Location: vancouver
Default

Tried it again after work today. Fired for like a second then died. Then tried again and it started after a few cranks. Couldn't get it to not start instantly after that initial startup though. This is very confusing to me.... Im thinking the residual pressure valve in the tandem pump is sticking and not letting the pump build pressure very well. I'll try running a bottle of liquid moly through it and hopefully it'll held
Runninwild is offline   Reply With Quote
Old March 26th, 2020, 06:59   #8
Runninwild
Veteran Member
 
Join Date: Jul 2018
Location: vancouver
Default

Drove the truck to work yesterday. Ran flawlessly all day. Started first crank the 6 or 7 times I tried. Went in to start it this morning and just had endless cranking. Temp was 5c so I don't think that's an issue. Only code it's throwing is for VSS p0501. Anyone have any ideas?
Runninwild is offline   Reply With Quote
Old March 26th, 2020, 08:47   #9
Tom in PT
Veteran Member
 
Join Date: Jun 2017
Location: Twilight Zone, WA State
Fuel Economy: 41 mpg in '05 ; up to 57 in '13
Default

Check your fuel filter- is it completely full of fuel?
Tom in PT is offline   Reply With Quote
Old March 26th, 2020, 12:15   #10
Runninwild
Veteran Member
 
Join Date: Jul 2018
Location: vancouver
Default

Quote:
Originally Posted by Tom in PT View Post
Check your fuel filter- is it completely full of fuel?

I popped the t the other day and turned on my primer pump and fuel started spraying out. I'm gonna try and flip my fuel lines. There's a chance I hooked them up backwards when I changed the fuel filfer
Runninwild is offline   Reply With Quote
Old March 26th, 2020, 13:01   #11
1.9glstdi
Veteran Member
 
Join Date: Jan 2010
Location: J-vill,FL
Fuel Economy: 37MPG around town automatic poo poo
Default

If you don't have a VCDS cable, you need to get one or find someone near you with one.
__________________
2005 4dr Golf, Reflex silver,BEW PD, auto/tippy, 20% tint all around, FL plates
VR6 suspension, tt lca's
Egr blocked, Dog collar
I Have vcds KII-usb for 2005 and older
1.9glstdi is offline   Reply With Quote
Old March 26th, 2020, 16:25   #12
Tom in PT
Veteran Member
 
Join Date: Jun 2017
Location: Twilight Zone, WA State
Fuel Economy: 41 mpg in '05 ; up to 57 in '13
Default

Could the no-start be caused by an interlock mechanism - transmission not in Park?
Tom in PT is offline   Reply With Quote
Old March 31st, 2020, 21:32   #13
Runninwild
Veteran Member
 
Join Date: Jul 2018
Location: vancouver
Default

Quote:
Originally Posted by Tom in PT View Post
Could the no-start be caused by an interlock mechanism - transmission not in Park?
No my ignition is wired directly to my ecu and starter. I combined all the grounds from the ecu to a single wire. I'm gonna try and split them up a bit and add some grounds to the motor. Maybe the injectors just aren't firing properly to get it started
Runninwild is offline   Reply With Quote
Old Yesterday, 03:50   #14
oilhammer
Certified Volkswagen Nut Vendor
 
oilhammer's Avatar
 
Join Date: Dec 2001
Location: St Louis
Fuel Economy: fantastic
Default

Does your electric pump deliver the same volume that the car's original lift pump did? I do not know how to figure that out, other than running an OE lift pump into a graduated container and measuring the volume over time... but perhaps your non-OE pump is not up to the task, and it has been causing the tandem pump to be overworked?

Remember, on a diesel, the fuel not only powers the engine, but it also cools and lubricates the fuel system. Which means much (most) of the fuel flow from and back to the tank is for that. The engine itself is only using a small percentage of the volume being circulated around.

Also remember pressure does not equal volume. An aftermarket electric pump that may be sufficient to feed gasoline to some giant knuckle dragger V8 with a giant carburetor on top (my former redneck life recalls the popular "Holley 750 double pumper") may not be enough to make a TDI's fuel system happy.
__________________
oilhammer
www.cardocautomotive.com
oilhammer is offline   Reply With Quote
Old Yesterday, 08:45   #15
Runninwild
Veteran Member
 
Join Date: Jul 2018
Location: vancouver
Default

From everything I've read a tandem pump doesn't 100% need a lift pump. When I first finished the swap I could run the engine and start the motor first crank with my primer pump turned off. It's not so much a running issue as much as a starting issue. Sometimes it starts first crank, sometimes I'm running the starter multiple times for a couple minutes to get it to fire. Usually during that time I might get it to cough once but it's not like it's stumbling and trying to get going. It's nothing but cranking until it fires 99% of the time and then as soon as it's running it runs smooth. Sometimes I'll crank it for 30seconds with nothing and then next turn of the key it starts first crank. Once it's started it runs fine. I put over 100km on the truck last weekend and other then being very hard to get it started it ran fine the entire time. ��*♂️ I'm not even convinced it's a fuel supply issue anymore. Id expect more stumbling and random fires while it primes if it was the case

Last edited by Runninwild; Yesterday at 08:48.
Runninwild is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Fuel filter and fuel system priming without VCDS? amstel78 VW MKVI-A6 Golf family including Jetta SportWagen (~ 2010-2014) 89 December 7th, 2016 18:57
HELP! injection pump priming issues oil4blood VW MKIV-A4 TDIs (VE and PD) 4 October 6th, 2015 18:54
Help! BEW tandem pump install; having issues priming aggieengnr TDI 101 4 February 2nd, 2015 15:46
DIY fuel filter - priming the fuel pump w/o VCDS mvfd403 Fuels & Lubricants 3 March 21st, 2013 07:00
Priming new fuel filter VATechTDI VW MKIV-A4 TDIs (VE and PD) 2 January 15th, 2004 15:08


All times are GMT -7. The time now is 11:37.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2017
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
1996 - 2017, All Rights Reserved
Page generated in 0.15527 seconds with 12 queries
[Output: 123.47 Kb. compressed to 103.13 Kb. by saving 20.34 Kb. (16.48%)]