E30 starts after 3-4 tries and after sitting for 10 minutes it won’t start again

[Maycollappost4002]

Hi good morning yall I need help please so I own a 1988 BMW 325I with 280,500 miles still going strong. So here’s the problem so I have a problem where everyday when I start the car I have to keep cranking about 4 to 5 times In order to fully start. It runs perfectly but when I drive it around then turn off the car an let it sit for 10 minutes i come to crank it up it would not start up again no matter how many times I crank it it still won’t start unless with starter fluid. I have changed the fuel pump, now fuel pressure regulator, fuel filter, new spark plugs, new distributor and idk what else to replace it’s just making me up set that I don’t know what to do

[Panici]

It sounds silly, but is the replacement fuel filter on the correct way? There are arrows indicating flow.

Have you put a mechanical fuel pressure gauge by the fuel rail to see if you're getting proper fuel pressure?

[Maycollappost4002]

Yes is in the correct way 😂 and no I haven’t not yet

[McGyver]

Is your fuel pump turning on? This could be a relay issue.

If you have a fuel pressure gauge, I would start by hooking that up to see if you have pressure. If not, I would start by checking wiring and making sure the fuel pump is firing up when the car is hot.

Electrical manuals are here (download your manuals for when they disappear):

http://www.wedophones.com/BMWManualsLead.htm

The Bentley manual has some great advice on trouble shooting a no-start condition:

https://www.r3vlimited.com/board/forum/e30-technical-forums/e30-faq-and-diy/128970-the-bentley-pdf-it-s-here

[82eye]

tee a pressure gauge on the fuel rail to check the pressure, it sounds like the fpr has had it and you are losing pressure on the rail unless the pump runs to bring it up.

[Maycollappost4002]

The fuel pump I have is brand new and thr fpr is new as well but when I crank it after letting it sit for 10 minutes I can hear it priming. I just brought a fuel testing kit.

[82eye]

The fuel pump I have is brand new and thr fpr is new as well but when I crank it after letting it sit for 10 minutes I can hear it priming. I just brought a fuel testing kit.

i've seen threads where a new fpr is junk from the box. best way to know is with a gauge teed in. it honestly sounds like you are losing pressure.

eidt : leaking injectors can do it as well though i'd expect other running problems.

[Maycollappost4002]

Now I finally tested out the fuel pressure as I was readying it goes up to 60 then drops back down to zero quick. Now I want to knwk if this a problem or what do I need to do to fix this?

[It's Soda Not Pop]

Does the starter spin but not engage the flywheel? Mine does this especially when it's hot outside. Next time this happens. Jump pins 11 and 14 in the diag plug next your intake (RS). Make sure the key is in the on position. The start should engage every time. I do this when my car won't start. I believe the issue is in the ignition switch.

[82eye]

Now I finally tested out the fuel pressure as I was readying it goes up to 60 then drops back down to zero quick. Now I want to knwk if this a problem or what do I need to do to fix this?

yup that's a problem. most likely fpr, engine off with pump jumpered should be 43 - 45psi, engine at idle should be 37 - 38 psi. engine at idle with fpr vac hose plugged should be 43 - 45 psi. there should be 35 psi or more at rest with engine off and pump not running. the rail never sees zero.

build up to 60 psi sounds like a clogged line or other problem on top of the fpr.

edit : the bmw e30 fpr is about 3.0 bar so the rail should never see more than 43 - 45 psi. do a search here to confirm. there's a few threads on it.

[Maycollappost4002]

Okay thanks I really do appreciate it alot now here’s my last question what kind of injectors can I use. From the research I’ve been doing I’ve been seeing that 535i injectors can be used in a 325i. Can I use them or no but if I can’t what kind of injectors can I run in my car

[digger]

something in the stock style around 15-17lb/hr usually works without issue if you need to replace them.

Years ago i had injectors cause issues when restarting after 10mins it just cranked and cranked but would start. i actually dont know what the issue was as they didnt leak according to the guy that tested them so i just replaced them and never had the issue again.

[TobyB]

eidt : leaking injectors

So much this...

To confirm, when it won't restart, floor it and crank. It's called 'flood clear mode'...

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