Warm Start Problems E30 M42

[dark_islight]

My 1991 e30 318is was having a problem when starting after it had been parked with the engine hot for more than 15-20 mins.

Symptoms were as if it had no fuel in the line. Cranked over 6-8 times and then stumble and start and run fine.

I did research on the internet and found that similar problems had been posted on other BMW websites. see: http://www.bmwe34.net/Wiki/tiki-index.php?page=535i+hot+start

I never checked with BMW in Canada for availability.

Note: The repair kit is inexpensive but costs more than its worth in shipping.
Bulky packaging. Kit consists of the replacement fuel line with the check valve already attached (you will cut this to length for your application) and some new clamps (crimped type clamps you may wish to replace with screw type clamps) and some insulation tubing and plastic nut covers (this can be discarded as you may not use this for your repair)

I finally had enough and I purchased BMW check valve p/n 16149068988 from  Steve Haygood in the states. You can see his site at http://www.stevehaygood.com:80/





Pre install



Post install



Car starts without hesitation now!!!!:rolleyes:

Important Note: Do this outside not in the garage!!!!

Very simple. Disconnect the fuel pump power supply and fuel sender connectors. Takes 30min, just have everything ready, Clamps, tools, fire extinguisher and pre cut the fuel hose before you disconnect the feed line.

Be prepared for some fuel to leak back down towards the fuel pump, have some rags handy.

This retrofit can be done on all e30's that have the fuel pump in the tank under the rear seat as shown in the DIY. I did this on my 91 318is with the M42 engine. I have had no starting issues since the install.:rolleyes:

[kowalski]

ahh good to see you brought it over here.

[Vladi]

Hm, well why does this happen only to some and not all engines with in tank pump?:confused:
Mine starts normal.

[SamuthNBS]

This is really useful, my car has been doing this. Perhaps I don't need a new pump after all.

[318ls]

Did your car have the idle problem for the first min after a warm start?

[kowalski]

Hm, well why does this happen only to some and not all engines with in tank pump?:confused:
Mine starts normal.

it doesn't happen to every car e30, just some. if the check valve wears. as well it can also be the fuel pressure regulator, if you block of the return line and the fuel pressure still drops its the fuel pressure regulator. if the fuel pressure doesn't drop when the return line is blocked, then its the line check valve you need.

[strad]

Important Note: Do this outside not in the garage!!!!

Yes.  If you have a water heater in the garage and you open the fuel system inside, BOOM!!!  One less bimmer fan.

[dark_islight]

Hm, well why does this happen only to some and not all engines with in tank pump?:confused:
Mine starts normal.

I believe the check valve in the pump gets tired and leaks fuel back into the tank. With the addition of the 2nd check valve outside the tank it solves the problem without having to change the fuel.

[dark_islight]

Did your car have the idle problem for the first min after a warm start?

No I didn't have idling issues at all it ran normally.

[JP 91iS]

Interesting read.  

Your link to the bmwe34 page leads to a page full of html, here is the working link:

http://www.bmwe34.net/Wiki/tiki-index.php?page=535i+hot+start

[dark_islight]

Interesting read.  

Your link to the bmwe34 page leads to a page full of html, here is the working link:

http://www.bmwe34.net/Wiki/tiki-index.php?page=535i+hot+start

Thanks for the info. His page was updated since I posted the thread. I have edited the web link..

[txleadfoot]

my fuel pump only has one outlet (no return line at the top).  I wonder if this will work on my '92 ic?

[big red]

This sounds really familiar. I'll definatly try this instead of going straight to the pump ! Thanks  All the little things that everyone's had to go through sure make's a differance to those of us who haven't gotten there yet.