Fuel pump not priming

[It's Soda Not Pop]

Also if your car has the 13 button OBC there is a module that will kill the ignition when you put in a code to secure the car. Sometimes this will go bad or malfunction. I don't have this but I've seen where this could be an issue. My apologies for not knowing more about it.

[It's Soda Not Pop]

After a month almost still noting..... I even took it to a shop and they were confused. Going to just go ahead and replace relay and go from there.

Can you give me a quick run down of what it is doing now? I know before it would start sometimes. But is it doing anything different? Long cranks, not cranking, starting and then immediately dying, etc.? Literally my issue was a mixture of a couple of things.

• Car would buck sometimes while driving.
• Would not crank when hot (either the engine bay or outside summer time)
• One day at my Brother's house the car would crank but would not fire.
• I pulled off the fuel line and it was dry. Not pumping fuel
• I believed it to be my fuel pump that had died. It didn't need to be replaced I just assumed it. But either way its changed now.
• So I replaced my fuel pump with a Walbro 255 that I had from CAtuned.
• After replacing the pump the car still would not fire.
• I called a friend of my and borrowed his DME Relay and the car fire right up.
• After idling for a bit the car died. Blown fuse.
• After reading online and even looking at the fuses on my friends car I replace the 7.5A fuse with a 15A fuse. The pump pulls more current.
• So now the car would start and stay running.
• Then I noticed the lights were getting Hella bright all of a sudden. Alternator was overcharging. Replaced it.
• Now everything is running and stayed running but I was having long crank times.
• I figured out that the Walbro 255 doesn't have a check valve.
• So I put an inline check valve before the fuel filter.
• After all of this it fixed my issue. Every now and then I'll get a hard start when it's really cold but nothing crazy.

[tjclemens2]

Any news?

After a month almost still noting..... I even took it to a shop and they were confused. Going to just go ahead and replace relay and go from there.

[laidback93]

Will the engine eventually fire up? I had a very long crank time which I couldn't figure out because I had recently replaced the fuel pump. Turns out the new pump had a bad check valve that opened itself up. Apparently there was a bad run of the Delphi pumps with many of them failing.

[dnguyen1963]

Don't forget to check the infamous CPS. If it is dead, no amount of cranking will fire up the engine.

[nando]

What year is your car? only the M42 cars prime the pump. the M10 318i doesn't, neither do any of the M20 cars or the S14.

[It's Soda Not Pop]

Any news?

[It's Soda Not Pop]

No worries sometimes it will be the simple things that we overlook.

[tjclemens2]

Just thought of something. Open up your icv so that there is a vacuum leak. See if the car will start. It will idle high. Maybe your ICV is bad or stuck closed.

A lot of great information!! I’ll go ahead and go over a little checklist tmrw when I go to try and get it started. Really appreciate the help and I’ll let you know if any of that works🤘

[It's Soda Not Pop]

Just thought of something. Open up your icv so that there is a vacuum leak. See if the car will start. It will idle high. Maybe your ICV is bad or stuck closed.

[It's Soda Not Pop]

On the M20's the ICV buzzes when you turn over the key.
These cars are old and after a million hot and cold cycles things tend to not work as good/or at all. I'm a while you're in there kind of person. So I would replace what is very old if you haven't already done that. But jumping the fuel pump relay while the key is in the on position should make the pump run. If it doesn't could be the wiring. more than likely it's a fail relay or worn component.

[It's Soda Not Pop]

. Is a good way to check relays by jumping them to see if it’s the relay that’s not completing the circuit?

you could do that or if you have a friend with an E30 borrow from them. That's what I did. Or you could just order some anyway. Peace of mind.

[tjclemens2]

unless the inline 4s are different the fuel pump doesn't prime on a E30. The fuel will not turn on until you are actually cranking the engine over.
Is it cranking every time you try to start it? I had an issue with my Main relay going out when it got hot. I had to replace my relays and because I went with a higher flowing pump it would pop the 7.5 fuse ( went to a bigger fuse). Could also be a ground or the harness grounding out.

. Is a good way to check relays by jumping them to see if it’s the relay that’s not completing the circuit?

[tjclemens2]

Ok thanks for the quick responses. So I may have explained it wrong but basically when I turn the key I don’t hear a buzz which I normally hear meaning the pump isn’t getting power I belive. I left the car for 5 hours cause I was at work and it was in the shade so it wasn’t hot. I will look into the relays, and as for the fuse I put a 15 in there but other than that I’m a little lost on what to do. I’m going to pick it up tmrw morning so I’ll see if it starts up so I can bring it home and take a look. Any ideas of where the ground it on the harness?

[digger]

What I'm about to write might be of no use to you but on a 325i the pump wont run until engine is rotating. Not sure if 318i is the same. I've had issues with injectors cause a no start after sitting for 10min i.e. hot/warm restart