1976 E12 wont start

[hotshu]

Hello, my 1st post on this forum. It's a 530i with a rebuilt 2.8L engine. I have spark, but no fuel. Fuses are ok. Where should I check next? I'm thinking of hot wiring the fuel pump to test, but where is it? Sorry I'm an E12 newbie. Is there an online manual or pic/diagrams on the web? Thanx!

[Martin in Bellevue]

I'd start by checking:
∙ pull the plugs & check for fouling
∙ Pull cap & rotor & check for cracks, carbon tracks
∙ verify fuel pressure to the carbs or injectors
? Is this one of those l jetronics with the fuel pump distributor, like a 2002ti, with a pump belt that needs to be lined up?

[hotshu]

Thanx for the reply. The sparkplugs were fine, as were the cap & rotor. It had been starting & running fine previously. Plugs are dry, no fuel getting to the cylinders. I pulled the cold start fuel injector & no fuel will come out of it while starting.

Not familiar with fuel pump distributor, that's why I'm looking for online pics sources.

Where's the fuel pump in the 5 series?

[rob101]

probably near the fuel tank, you should check out the special e12 site

www.firstfives.org

I think the 2002 has K-jet not L-jet. one is MFI the other is EFI biiig difference.

[rob101]

Hello, my 1st post on this forum. It's a 530i with a rebuilt 2.8L engine. I have spark, but no fuel. Fuses are ok. Where should I check next? I'm thinking of hot wiring the fuel pump to test, but where is it? Sorry I'm an E12 newbie. Is there an online manual or pic/diagrams on the web? Thanx!

be aware that there are 2 pumps, transfer and main, main will be near the fuel filter, under the car in front of the right rear suspension if i remember correctly (and if its the same as the e28)

[winfred]

320i is k-jet with a fuel distributor, 2002tii is mechanical with a belt driven injection pump

I think the 2002 has K-jet not L-jet. one is MFI the other is EFI biiig difference.

[Karl]

I also have an e12, though mine is an 81 528i (with 535i engine). Still running the original L-Jet, though I've tweaked it for the larger engine.
Common "no fuel" failure is the combination relay that controls the fuel pump, among other things. It's a double relay looking little black box on the left fender a little forward from the brake booster. Check by removing the rubber air hose that goes from the air filter to air flow meter. Then turn on the ignition -- to run, not start -- and push open the door in the air flow meter. When the door is a little open you should be able to hear the relay click (over near the brake booster) and fuel pump start to run (back by the right rear wheel). While you're at it, make sure the air door moves with no drag. It's also common with age for the air flow meter housing to warp and bind the air door. But when that happened to me the door stuck partway open so the car was dead rich at idle. BTW the fuel filter is next to the pump near the right rear wheel. If you haven't changed it in a while it's due.

For more info go to the firstfives.org web site and check the FAQ for the relay and AFM. Hope this helps

[wingman]

I'd also go for the fuel pump and/or relay. I used to have trouble with the power leads connected to the fuel pump getting 'unconnected'. Listen for the fuel pump on start up (location as previously described). You may also have a lot of crap in the fuel pump. They have fine tolerances and can clog easily especially with old fuel lines( I went through 3 in 10 years). The Bosch fuel pump is quite pricey so I went for an after market inline pump as used in the GMH VL Commodore/Nissan Skyline. You just need one with the same flow as the 2.8. If it is the regulator you will also find these to be quite pricey (around US$150-180) You may want to change your fuel lines if the problem is ongoing. Definately change the filter!!!

[rob101]

320i is k-jet with a fuel distributor, 2002tii is mechanical with a belt driven injection pump

thank you for the clarification, ah yes thats kugelfischer injection system my mistake.

[Jon K]

just check the fuel pump for run, you can usually hear it have someone turn the car over 2 acc 2, or simply jumper the relay and see if the pump(s) function.