Radium fuel pump install - car cranks, won't turnover first try after

[bigjae46]

I installed this radium kit to convert the fuel pump to a Walbro unit. So I try to start the car and it just cranks. If I shut the car off and try again it fires up. Anyone else experience this with the Radium kit?

Fuel Pump Install Kit, 96-06 BMW (radiumauto.com)

[enjoy_m3]

Looks like it has a hard time building pressure. Might be the internal check valve in the pump. I had this issue with an AEM pump, I called aem and they sent me a replacement unit which I used on a different car. It didn't have issues. Try driving the car often for about a week and see if it doesn't go away. Then look into a faulty check valve. I looked into installing a checkvalve after the filter but never got around to it. Switched to a deatschwerks pump and it got better but still do it from time to time, but I do run APE flex fuel and have different mixes on the tank to experiment on the mpg.

[EthanolTurbo]

Yes mine does too but I only run it on E85 so it's normal to do that on a cold start. Haven't tried it on pump gas on a cold start.

[ethan]

I reused the stock PTFE hose between the housing and the pump when I did my conversion, and it would leak down around the barb and exhibit the symptoms you describe. Otherwise, maybe you got a counterfeit Walbro without a check valve (common on eBay) or a legit one with a broken valve.

[L0okitzRaj]

I have this issue without the radium kit. Car will crank forever and not start, but if i stop and try again, it fires on the first crank. Maybe it isn't the radium kit?

[heinzboehmer]

I reused the stock PTFE hose between the housing and the pump when I did my conversion, and it would leak down around the barb and exhibit the symptoms you describe. Otherwise, maybe you got a counterfeit Walbro without a check valve (common on eBay) or a legit one which a broken valve.

Agreed that first suspect is that hose.

I also had the same problem when I used a Walbro with the Radium kit . I replaced it with an AEM pump and a new bit of the PTFE hose and problem went away. Unfortunately changed too many variables at once to know exactly what the issue was.

[loudspeaker69]

Does anyone have the PN or link for the AEM pump and the PTFE Hose


I have the same problem. My vehicle doesn’t crank on the 1st try and I have the Walboro Fuel Pump from Radium Engineering.

[ethan]

Does anyone have the PN or link for the AEM pump and the PTFE Hose


I have the same problem. My vehicle doesn’t crank on the 1st try and I have the Walboro Fuel Pump from Radium Engineering.

Try a new one of these before the AEM pump if you're price sensitive:
http://www.radiumauto.com/Submersibl...bing-P672.aspx

I had the same problem in two different M3s using fresh Walbros direct from RE. In both cases, a new hose installed with a heat gun and the included clamps solved the problem. I lived with it for years and it was just that simple...

[ethan]

I have this issue without the radium kit. Car will crank forever and not start, but if i stop and try again, it fires on the first crank. Maybe it isn't the radium kit?

Did you replace your fuel pump with aftermarket? In one of my M3s, I installed a Walbro by using the exterior shell of the original pump (cut off with a dremel) and wrapping the smaller Walbro replacement inside it and clamping it with a worm gear clamp. Achieves the same thing as the RE sleeve but jury-rigged. Had the same starting issue with that pump too until I replaced the stock PTFE line. I think what happens is they get expanded coming off the original barb and don't make a tight enough seal when installed on the new pump. They're also sitting in fuel for a decade or so, so they lose flexibility which is needed to return to tight after slipping over the barb.

Could also be a bad (or non-existent in the case of eBay knockoffs) check valve on the pump outlet.

[loudspeaker69]

Try a new one of these before the AEM pump if you're price sensitive:
http://www.radiumauto.com/Submersibl...bing-P672.aspx

I had the same problem in two different M3s using fresh Walbros direct from RE. In both cases, a new hose installed with a heat gun and the included clamps solved the problem. I lived with it for years and it was just that simple...

That sounds like a great solution.

Also wondering if one can use the OEM hose…
If it’s sold separately ?

[heinzboehmer]

Also wondering if one can use the OEM hose…
If it’s sold separately ?

It's not sold separately. The Radium hose is what I used on my car.

[eacmen]

I’ve known a couple folks that needed to retrofit an inline check valve when using aftermarket pump.


Sent from my iPhone using Tapatalk

[loudspeaker69]

Try a new one of these before the AEM pump if you're price sensitive:
http://www.radiumauto.com/Submersibl...bing-P672.aspx

I had the same problem in two different M3s using fresh Walbros direct from RE. In both cases, a new hose installed with a heat gun and the included clamps solved the problem. I lived with it for years and it was just that simple...

I might give this a shot !

Which one is the correct size ?