Trying to get engine to start after swap

[andrew_baran]

I'm trying to get my engine started after my first ever engine swap. I've swapped my 1990 m20b20 for a high comp b25. The engine turns on the starter freely, but there is no spark and no fuel coming through.

- I've used the new engine loom that was already on the engine when I dropped it into the car.
- I've changed the CPS from the engine that came out of the car, so it's a known good unit.
- The ICV doesn't buzz when I have the DME relay in, does when I bridge the 87s with the 30. No fuel or spark when wires are bridged.
- I changed the ECU chip to a 325 one from Speedtouch on here, but the ECU was known good before the swap...

What's should my next load of checks be? Could it still be immobiliser/alarm related somehow? The car does have a butt load of dodgy looking alarm wiring above the glovebox, but it turns on the starter...?

[Brianmoooore]

Connect a 12 volt bulb between the + terminal of the ignition coil and the main earth terminal on the top of the RH strut. Does it light when you turn the ignition on, and continue to be lit when you crank the engine.

[FinalD]

Sounds similar to what I had happening with my car...

http://www.e30zone.net/modules.php?name ... c&t=231489

Second to last post:

Oh. My. Fookin. Gawd.

So I removed the wire that someone said was for the OBC in another thread because I have no OBC, thought nothing of it.

Today, figured 'just make sure that wire doesn't make any difference' plugged in, turned key...wnker, fookin works. Looked at the cable, turns out it has been butchered and the wires soldered together then recovered in tape fairly well so wasn't obvious it had been done.

Cheers for all the help guys, typical that it was something so damn simple though.

Just a thought anyway.

[andrew_baran]

Bulb to coil last night - no light.

- Bridged coil, car sparked but didn't start. No fuel smell.
- Bridged fuel pump, can hear it pumping no problem.
- Continuity checked between c101 and pin 15 of coil. All ok.
- Checked fuel pump fuse.

I can't find the green and red/green wires for the OBC behind the glovebox. I've never had an OBC, and the car used to run before I swapped the engine out..

[andrew_baran]

There is this bundle of joy behind the dash though...



Old alarm system?

[Grrrmachine]

Brian's bulb-on-coil is the very first step in this diagram:

http://www.e30zone.net/e30zonewiki/inde ... oubleshoot

[andrew_baran]

Yeah, that article is absolutely amazing. So helpful.

I'm a bit confused now.

Does the green wire affect the injectors etc too? Why would the car now spark but not fuel? I tried a diagnostic plug start as well as on the key.

[Brianmoooore]

The green wire immobiliser plug is very obvious in your pic. - right in the middle.
If there's no continuity between the two green wires to the top of the plug, there will be no power at the + terminal of the coil, and the engine ECU will not be switched on, in turn not switching on the DME relay, which controls power to the injectors and fuel pump relay.
Pull the plug from the immobiliser socket, and join the two greens to the top together and try again.
At this point we know we have an immobiliser problem to the green ignition 'on' wire, but we don't know if there is also an immobiliser circuit connected to the fuel pump, or if there is some problem with the replacement engine, totally unconnected with immobilisers.

[andrew_baran]

Right. That makes me feel a bit stupid. I looked at that yesterday and dismissed it as it didn't have a green/red. I'll connect those together and chase back that immobiliser wire.

Thank you for helping with this - I really appreciate it.

[andrew_baran]

Bridged the green immobiliser wire together last night - turned the car over and got a splutter. So I taped it all together temporarily and tried properly - with a bit of help on the throttle the engine started and ran.

I'm assuming that this means the alarm/immobiliser system has become unhappy since I changed the engine. Either way, big progress - my e30 is one step closer

[andrew_baran]

And now it doesn't again.

Fuel present. Spark present. But it just won't catch. Checking for leaks etc and seems to be fine... Blue plug checked for correct resistance.

[Speedtouch]

Are you sure your 'temporarily taped together' wiring is connecting properly?

It may be that you've flooded the engine, in which case, you'll need to remove all the spark plugs and dry them off.

I assume you have enough fuel in the tank? Some carb or brake cleaner sprayed down the throttle body may help kick it back into running order.

[andrew_baran]

Lol, the wiring is /slightly/ bodged, but the connection is good and strong. We cranked the car without the fuel pump fuse in until it cleared, then tried again with carb cleaner.

We got one splutter with the carb cleaner into the intake, then couldn't even get it to do that - no matter what we did with the starter/throttle etc.

Lots of fuel in the tank - over half full.

[Speedtouch]

Is the engine-to-body earth strap in place and securely connected?

Also, is the CPS correctly positioned?

[Grrrmachine]

Remember with the blue plug you're not just testing the sensor, but also the wiring. If you've got corrosion of the C191 plug, or you've disturbed the pins on the connector then the ECU gets a false reading and massively overfuels. That's why you need to test from the ECU plug.

[Ant]

and given you had the engine ot, could the inlet and return pipes be the wrong way round on the fuel rail ???

return comes off the stub on the FPR, inlet via inline filter to rail stub

[andrew_baran]

Engine earth is on properly. All looks fairly new.
Checked the fuel pipes - confident they are the correct way round.
I'm guessing that the CPS sensor is mounted correctly, given that i have spark...
Checked for air leaks before the TB. All good.
Checked that the engine has the bung for the carbon canister under the TB - does.

Still got to check for the blue plug resistance at the ECU end. Going to hopefully do that tomorrow - lost my multimeter...