my mk3 cranks and wants to start, but won't
 

Hi, I've read several threads on here about this exact problem. However, I haven't found a solution. I bought my '87 mk3 with a blown head gasket. I replaced the head gasket. The car won't start though. The engine cranks and cranks but no go. I have spark. I have fuel. I've replaced my spark plugs and wires. I've replaced my ECU. I've replaced my coil ignitor. I've checked the timing. Any suggestions? I'm sure I'm missing something. I'm just not sure what?

Make sure your ignition timing is set right. Sometimes it takes a little trial and error of pulling out the distributor and turning the gear to get it to the right range to fine tune the timing.

Thank you. I'll give that a try. I've done it before, but I may still be off the mark.

my mk3 cranks and wants to start, but won't
 

Hi ! , I had the same problem when I did my BHG . The answer was found underneath the inlet manifold . I had forgotten to reconnect all the earth ( ground ) leads to the manifold . once connected she burst into life.

Thanks. I'll pull the plenum off and take a look. I hope I haven't missed something so simple as that.

I had rthe same issue.

I tried the following which worked for me...

a) Check ALL Earthing points
b) Ignition timing needs to be correct or the engine wont start.

It takes time but its worth it ...

Let me know how it goes...

Make sure that bundle of harness ground wires low down on the intake side of the manifold is tightened down otherwise you'll get weird things. I had mine hand tight and it was acting very squirrelly. When you install the cam position sensor or distributor follow the alignment method otherwise the timing will be off. The same goes for the camshafts and the crankshaft. They all need to be in time to work properly. The firing order is 1 5 3 6 2 4 on a distributor cap. The rotor cap will be pointing to 1 when installed properly and with 1 at the top of the compression stroke. The coil pack wire order from left to right is 1 6 3 4 2 5. Check for spark using a good spark plug held against a ground point while someone cranks the engine briefly. When you get it started and warmed up, jumper T1 to TE1 and set the timing with a timing light to 10deg BTDC at idle with the air conditioning off. You may want to check your fuel pressure to see if you have any. You can "hear" the fuel flowing at the rail by turning the ignition switch to the on position but not cranking and then jumper B+ to FP in the diagnostic block behind the fuse box. Mack sure all electrical plugs are plugged in. Lastly, if yours is a Turbo, you can wiggle the wires that go into the cam position sensor. I had one that was funny that way.

Here are links to the on line repair manual.

valve timing
http://www.cygnusx1.net/Supra/Librar...aspx?S=EM&P=29

ignition timing
http://www.cygnusx1.net/Supra/Librar...aspx?S=IG&P=20

non turbo distributor
http://www.cygnusx1.net/Supra/Librar...aspx?S=IG&P=17

turbo cam position sensor
http://www.cygnusx1.net/Supra/Librar...aspx?S=IG&P=21

ground points
 

by any chance you guys know where all the grounds are in the engine, cause I'm having the same problem i just wanna make sure I'm good.

The 4 grounds I can think of on a Turbo car are :
1. The harness bundles that bolt to the intake manifold.
2. Ground strap at the rear engine installation hook.
3. Ground strap down low where the engine meets the transmission on the left side.
4. Ground strap at the transmission rear support bracket.

I added an extra ground strap in the shape of a Y that goes from the engine ground strap bundle (1.) to a bolt on the igniter and that splash shield that covers the steering column shaft.

Check your codes then pull the EFI fuse and check the codes again after trying to start it.
See if any persist.

awesome
 

great thanks man i'll definitely try that. I was rebuilding also and I'm have trouble with this so its really insightful.

my mk3 cranks and wants to start, but won't
 

Hi , Did you get your car going ? I forgot to mention there is a ground strap connected to the plate holding the ignition coils . I modified mine by extending and connecting directly to the inlet manifold . The forum would be pleased to know what success you had .

progress
 

we'll thanks for that response I'm glad you said it. Well I put the ground kit in which is cool. Sadly tho i know thats not gonna make this car start. So current situation is gets power... Cranks but no go... just got the CPS cover so now I'm gonna do timing and all that to see if it'll start.... Also the fuel relays keeps going off tested relay works so maybe pump..? I get fuel tho cause spark plugs smelled like gas... Was leaking gas too... Fixed it. I've gotten leaks like oil and all that so i fixed them.... Any input would be much appreciated... Don't wanna give up on this car...

my mk3 cranks and wants to start, but won't
 

Hi , I have just remembered a case where I had to change a blown hose and forgot to reconnect the wiring to the airflow meter . Would not start without it . Maybe worth looking at a dry joint there . Keep going .
Possibly a good idea to make a list of possibilities and thoroughly check and cross off each when done . What is left could be the problem . Even been known to have double and triple faults . Always have at least 4 gallons of fuel in the tank for testing .

hardship to success
 

Kay I'll check that. I've done the timing and with the cover and ground i noticed a change in sound when i crank it. Sounds strong and responsive more, I'm gonna look up all the issues regarding no spark and further it from there. I'm sure I'll find out thru process of elimination. A little happy I'm seeing more progress with my hardship in this car. Should i be concerned that the check engine light isn't showing...? Since I did the Timing and Ground it ceased.... Maybe a Fuse...? Any who I don't expect answers for those just conversation