Hey guys! It's been a while since I've posted. College does that to you I guess haha! So I recently swapped the short block out of my car because it had rod knock. As soon as I got everything back together, I got no crank from the start motor, which turned out to be a bad ground. Now, I have an issue where it cranks but does not start. I have four codes: P2300, P2303, P0201, and P0341. All of these codes are related as they're all on the same wiring harness in the wiring loom from the ECU, particularly after the big "octopus" ECU wire harness diverter junction thingy below the air box. So far, I have replaced the battery because the old one was killed from having to close windows multiple times while moving the engineless car around for people to use the Motorsports Club Garage at school (and rain came). The wiring was all sealed well so I did not expect anything to have shorted, and tonight I just tested if anything in that harness had shorted. I used a multimeter to check for voltage across the terminals in the fuse box in the engine bay. Fuses 2, 3, 4, and 5 are all reading just under 10V from battery+ to ground when the car is in accessory mode. I also tested resistance across the other terminal of the fuse box to ground looking for infinite resistance (which it was thankfully). I then ran the positive lead to that same terminal in the fuse box to certain pins in each fuel injector plug, the ignition coil plug, and the crank position sensor plug from the wiring harness checking for zero resistance. The resistance I observed was 0.7 ohms which I went to assume was so small in this scale that it was acceptable. I am now at a wall with what else I should do. I cleaned up the main engine ground points too. What should I test next?

Here's some pictures from the engine swap:

This was the first day I started working on the car, prepping it for the engine to come out

This was the next day

The motor came out surprisingly easy

The damage speaks for itself...


This is the day I picked up the engine

I got the cylinder head on a couple days after picking the motor up


This was three days ago

This is the stage the car is at currently. Just trying to get the motor sorted ASAP because I'm so ready to drive it!

 

Check voltages at the DME.
With the ignition on, you should be seeing close to 12V on the connector for the DME for the pins that feed the ignition coils and injectors.
You can also check resistance of the wires from the coils,injectors and cam sensor going to the DME.

 

I’m having the exact same problem. Where/how should I check the voltage?

 

Details matter -
Sean wrote - "Swapped motor, now car turns over but does not start".

How can that happen ? I doubt that the starter has enough power to turn the whole "car".
I'd guess that the starter is turning the "crankshaft", NOT the "car"...correct ?

I'd assume that somewhere, one of your collage classes, may help you with conveying the "details" fully and correctly. It may be a very positive step in the future.

Mike

 

And I thought that I was a pedant.

 

This is why alot of folks on here are hesitant to ask any questions.
Instead of being a @#$.
Lets ask him some questions.
Did you check to plug going to the DME. Make sure you did not bend the pins.
Are you sure you hooked up all your grounds.

 

OP, I like your enthusiasm and ambition to take on a project of this size.

You say you see 10V at several of the fuses. Off the cuff, that seems awfully low. Do you see 10V across the battery terminals? Maybe you need to charge that battery... As mrbean notes, you generally want to see 12V and if lower it suggests a depleted battery.

 

This question could be interpreted a few ways. Let's start here: do you have a digital multimeter? Do you know where chassis grounds are?

 

Did you keep the original engine harness or the harness from the donor engine?

I put in an 05 engine and harness into my 06. No go- had to put the 06 harness back on. Something was different. Wouldn’t start and got lots of communication faults.

 

Yes on the digital multimeter…

I know where the one on the motor mount is…been having problems locating all the points in the electrical components PDF I found online.

I did find that my motor mount ground point was loose. I tightened it and she runs! But where else should I check?

 

Bentley lists all ground points. TIS also

 

Sorry, but I don’t know what TIS is and I don’t have a Bentley manual. 😟

 

TIS is the manual bmw uses. Available for download for free.

all the info you need in my thread named “inpa”. See post #16.

 

Thanks! I need all the help I can get. I’ll check out your post in the other thread👍🏾

EDIT:

And I think the manuals I’ve got are TIS…I’d have to see a page out of o e to compare.