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Engine Specific Info and Questions => Diesel Swaps => Topic started by: Smoker on September 29, 2014, 12:40:14 pm

Title: tdi swap... no start
Post by: Smoker on September 29, 2014, 12:40:14 pm
ahu in a caddy.  Wired via the piggyback method.  I have a very few details that still need to be sorted (waiting for my N75 to show up in the mail) but I figured I'd prime it and try to fire it this morning.

I think I have everything wired correctly.  Fuseblock is powered.  Fuel shutoff is getting power.  I'm getting fuel at all four injectors.

It won't even think about firing.  No sputter or anything.

Motor came out of my daily driver, so I know it's good.

So what am I missing?  I guess I'm assuming that because the fuel shutoff is getting power, that the ecu is getting power as well.  And even if it isn't, shouldn't a diesel at least start and idle if it has fuel, compression, and correct timing?

How can I check to see if I actually have power at the ecu? 
Title: Re: tdi swap... no start
Post by: thegimpster on September 29, 2014, 02:43:31 pm
to check if the ecu has power pull the ecu off and use a voltmeter to check for power and grounds on the main power pins. here is the pinout in pdf form http://www.haywood-sullivan.com/vanagon/TDI/1996_Jetta_TDI_wiring_LONG4.pdf

also you might hook up your obd2 port and try to pull the codes out of it if you have power and everything going to the ecu.
Title: Re: tdi swap... no start
Post by: Smoker on September 29, 2014, 06:49:05 pm
One thing I just noticed... this thing turns over waaay slower than my mk3 tdi.  Does the starter make that much of a difference?  (stock starter in my mk3, stock mk1 starter in the caddy)
Title: Re: tdi swap... no start
Post by: thegimpster on September 30, 2014, 10:34:09 am
is it a gas or a diesel starter? That could affect it some. i don't remember off the top of my head but i think gas starters are 1/2 hp and diesel ones are 3/4 hp ones. I had my mtdi in a caddy running off of a diesel starter and it did just fine. I would check the voltage and condition of the battery as well as the shape of the cables going to the starter for corrosion or general crappyness.

you might get a decent set of jumper cables and connect the negative one to the block and battery and the positive one to the battery and starter and see if that helps any.

did you check for power to the ecu yet?

Do you have any smoke coming out of the exhaust?
Title: Re: tdi swap... no start
Post by: burn_your_money on October 12, 2014, 08:34:52 am
You do need power to the ECU even to idle.
Title: Re: tdi swap... no start
Post by: Smoker on October 13, 2014, 10:13:30 am
Some updates.

Long story short, I ended up pulling the motor and swapping it for another one.  I turned the key and it fired right up.

However... after a few test drives, I went to start it and the 109 relay started going crazy, clicking real fast.  It will crank but not start.  Coincidentally, this happened after I plugged in the turn signal and wiper stalks.  I hate electrical problems!!  Any ideas?  I have another relay here, but I really don't want to fry it if this is being caused by something else.
Title: Re: tdi swap... no start
Post by: thegimpster on October 13, 2014, 11:54:53 am
I would start with checking grounds first. I think i mentioned that in a previous post, but VW ground gremlins will kill progress faster than anything.
Title: Re: tdi swap... no start
Post by: golftd412000 on October 15, 2014, 04:56:36 am
do you use a little manual prepump?to force-feed

for a reboot it happen to need to force on iq(hamer mod)

when you start the engine initialization of the actuator is?
Title: Re: tdi swap... no start
Post by: libbydiesel on November 03, 2014, 12:33:36 pm
I hate electrical problems!!

That seems kind of funny to me.  If you don't like dealing with electrical problems why would you have an eTDI AHU?  A properly built mTDI gives all the performance of an eTDI but is less labor, less expensive and more reliable.  The only benefit to the electronic engine management is the fun of playing with electronics.  I can almost see doing the eTDI for the VNT control on an ALH but on an AHU, if you don't think it's fun then there are only downsides.