Non starter 325i m20.

[Sanchez]

Hi peeps.

My E30 is cranking, has spark and fuel but won’t start.

It has a good battery which has just been trickle charged to rule that out.

It has no immobiliser.

Fuel is going into the fuel rail.

Tested spark on 1 and 4.

Compression test says 145/150 on all 6.

Changed the cps sensor.

Blue temp sensor says 1300ohms at ecu pins but wiki says 3500/4000, spare sensor says the same. Should I buy another?


Recently I have replace the hard fuel supply line to kunifer as I couldn’t get a bmw one posted by Cotswold and put new fuel filter in. Is it possible fuel pressure is too low? When I undo the fuel rail jubilee clip the fuel is under good pressure but I don’t have a tester for it.


What’s the easiest way to check injectors getting power, I think they are cause plugs were wet when I removed for compression test.


Can’t think of any other issues to help, does anyone have any ideas?

[Brianmoooore]

Has it run since the fuel lines were replaced?
Did it run immediately before they were replaced?
Blue temp sensor reading 1300 ohms? When I saw this, my first thought was that you were in a nice warm part of the world, but then I saw that your location was Scotland!!! In spite of this, I strongly doubt it's anything to do with your problem.
I take it that this reading was stone cold? Do you get the same reading if you measure directly across the two pins of the sensors,

[Sanchez]

Ran fine before fuel line work.

It ran once since replaced fuel lines but this was just for a short while to check the fuel line worked ok.

Blue sensor reading was the same at ecu pins and sensor on cold day outside in cold weather with cold engine.

[Brianmoooore]

In Scotland, at this time of year, the blue temp sensor should be nearer 4000 ohm than 3500. Are you sure your meter is accurate? Connecting the leads to a voltage source when on an ohms range can do damage.
If it has run since the fuel lines were refitted, the fuel lines must be the right way around, so what you have described in your OP is an engine that should start and run!
Anything else you've had apart, such as plug leads off, although with the standard lead holder fitted it's pretty difficult to get them on the wrong plugs.
Spark timing can't be wrong with a distributor mounted on the end of a camshaft.
If you have decent sparks and good compression, it only leaves fuel, so in spite of the wet plugs, this is where I'd start.
You could remove the big hose from the throttle body, and try to fire the engine up on gas, either from an aerosol of something like carb. cleaner, or from a gas blowlamp with the jet removed. You need to open the throttle slightly, since fuel mixture won't be going through the idle control valve.
I've fired up and moved cars around using a blowlamp on a few occasions - cars that din't have fuel tanks and pumps fitted or not working.
If fuel is the problem, the first place to look is under the lower boot of the plug and socket under the inlet manifold where the injector loom connects to the engine loom. This applies to post facelift looms only.
If you want to check the fuel pressure, and check for injector leakage, faulty non return valve, weeping hoses and FPR problems, a fuel pressure gauge kit can be obtained from ebay for around £20.

[Sanchez]

Think I’ll get a new blue sensor. Got 3 and read the same and all 3 don’t help to start.

Definitely got 6 plugs sparkling and fuel into the cylinders.

Very frustrating not getting it running today.

[Brianmoooore]

Are you sure your meter is accurate?

[Sanchez]

Are you sure your meter is accurate?

This is what I’m thinking.

[Sanchez]

Ok she ran last night for a wee bit. Doesn’t sound right but it’s progress.

[Brianmoooore]

How long is "a wee bit"? A cough or two, or it actually ran for at least ten seconds?

[Sanchez]

So Thursday night I went to take a ‘non starting’ video for online diagnostics help and after a long time cranking its spluttered as I turned the ignition off.

So I tried again and then it fired but very rough so shut it off after a minute or so.

Today it’s firing after a long cranking session and sounds like it runs better. It possibly has a hole in the exhaust manifold heat shielding. I ran it for 10mins and top hose didn’t firm up, hope the thermostat isn’t stuck.

When I take a spark plug lead off when it’s running is sounds different so I think running on 6.

From not running on Wednesday to today I’ve not changed or done anything to the car.

[Sanchez]

So it turns out that the connector on the top of the fuel pump it’s the best and wasn’t always allowing good circuit to the fuel pump. So fuel wasn’t always supplied and not enough fuel to start the car.

As I wiggled the connector you can just hear the pump working weaker or stronger. No she’s seams much happier.

[Brianmoooore]

If you want to check the fuel pressure, and check for injector leakage, faulty non return valve, weeping hoses and FPR problems, a fuel pressure gauge kit can be obtained from ebay for around £20.

Would have been £20 well spent!

[Sanchez]

Yep.