M20B20 does not start, fuel pressure

[123go]

Dobrý den,
potřebuji poradit. Můj motor m20b20 nejde nastartovat. Studený se točí a teprve po deseti minutách se spustí, ale dusí se. Když se zahřeje, funguje, ale neběží hladce, dokud se celé auto mírně netřese...
Stalo se tak po výměně palivového čerpadla a vyčištění nádrže. Ihned po výměně motor běžel...
Snažil jsem se dát regulátor paliva do jiného, ale nic se neděje. Senzory i relé jsou nové. svíčky a cívky také. Filtr samozřejmě také...
při měření tlaku paliva mám 2,6 BAR, ale tlak okamžitě klesne na nulu.
Zdá se mi, že jsem to musel zapojit jinak, než by to mělo být. Když fouknu do zpětné hadice, slyším, jak benzín teče do nádrže. a když dám kompresor za filtr, při 2,5 BAR otevřu regulátor a benzín se vrátí do nádrže.

[123go]

Yesterday I tried to clog the return hose behind the regulator and the car started normally. I tried to replace the regulator with another (functional) one from 2.5,. 3BAR and I didn't start...

[tomstin]

I think you will need to check the fuel pressure with a pressure gauge. Here in the states many auto parts stores will lend you the gauge. If you closed the fuel return hose that probably raised the fuel pressure enough to start. My guess is your fuel pump is weak, a pinched line or a fuel filter is clogged. Preventing the fuel from returning is adding enough pressure to get the engine to start.

[123go]

Here is a photo of the start-up. I didn't start, so I don't know what the pressure is when the engine is running...

[123go]

I added an external check valve and I seem to have solved the problem. The car starts normally, does not wobble and runs cleanly
image widget

[123go]

I added an external check valve and I seem to have solved the problem. The car starts normally, does not wobble and runs cleanly

[Christopher Siller]

I need help. First time ever using this forum so forgive any posting mistakes.

I rebuilt an m20b25 for my 92 vert e30 and after sorting out oil pump issues from using an ix block, i started the car for the first time. It seemed to be running fine, maybe a little rough but i figured that was because it was cold and freshly rebuilt seals, bearings, etc. however after letting it run for a minute or so i tried giving it a little throttle and the engine died pretty quickly. Now it won't start

Tested maf by swapping off my other e30, no difference.
Brand new fuel pump and filter so i don't think that's the issue.


Mainly confused because it was running so my guess is there's no major mechanical or electrical problems but now it won't start and dies if given any throttle.