hard cold start

[youngbimmer]

I left my car for a week undriven, came to start it today and was greeted by a long crank (about 15 seconds) and eventual sputter then proper idle, then some missing under load. The battery is fairly new, just put in a new fuel filter. Seemingly after some WOT runs, I shut off the car and it started back up without issue when warm and the missing went away. Ideas as to what's going on?

[shogun]

Probably the fuel line was not under pressure, as the fuel ran back into the fuel tank, usually the check valve inside the fuel pump fails, some people install an additional check valve on top of the tank that fuel is kept under pressure

[youngbimmer]

Probably the fuel line was not under pressure, as the fuel ran back into the fuel tank, usually the check valve inside the fuel pump fails, some people install an additional check valve on top of the tank that fuel is kept under pressure

Do you have a kit you can recommend?

[shogun]

BMW once had a kit, 16 14 9 068 988 , but NLA, installation as shown here in the feed line http://www.bimmernut.com/forum/showt...ht=check+valve
the are plenty of check valves in the net, just get one which fits the inner dia. of your fuel hose there, google for fuel check valve, less than $10/piece

[youngbimmer]

BMW once had a kit, 16 14 9 068 988 , but NLA, installation as shown here in the feed line http://www.bimmernut.com/forum/showt...ht=check+valve
the are plenty of check valves in the net, just get one which fits the inner dia. of your fuel hose there, google for fuel check valve, less than $10/piece

would it be ok to splice one in right before the fuel filter? or should I try to squeeze in the trunk as close to fuel pump? is diameter typically 3/8" or 5/16"?

[shogun]

near fuel filter is more difficult, lots of it are pipes and the hoses are short http://www.realoem.com/bmw/enUS/show...diagId=16_0801
and there you see that the fuel hose inner dia is 8mm from fuel pump to filter, so you need a check valve with 8mm outer dia = 5/16", for example these 2 for less than 10 $ http://www.ebay.com/itm/2X-5-16-8mm-...-/112037390124
note the arrow on the valve for flow direction.
On the tank is best position closest to the pump like installed here on an E30 http://www.bimmerboard.com/forums/posts/496880

[youngbimmer]

bought the valves, the clamps, and will get the fuel hose from advance auto some point later. Will try to install as close to fuel pump as possible, will take pictures if it helps others.

secondary note: power steering and my belts are squealing again. My friend when we put the new belts on said my adjustment nut needed to be replaced, but now thinks the tensioners as well? What are the part numbers for the tensioner on alternator and power steering? Build date 06/1989.

tertiary note: sounds like I have a vacuum leak, engine nagging noise at idle. Is there a E32 M30 vacuum diagram somewhere?

[shogun]

Vacuum hose diagram http://www.nmia.com/~dgnrg/page_2.htm under intakes https://www.bimmerforums.com/forum/s...ghlight=vacuum
tensioner p/ you can find with your VIN here http://www.realoem.com/bmw/select.do