E34/535 No start

[DABLACK]

Ok...i have installed a fuel check valve based on the car being hard to start only when cold and also the fuel regulator.... still nuttin. Any advice out there? am I lookin at a pump?

Thanks in advance

[Rus]

You might be looking at a leaking injector (or several). Have you checked your fuel pressure? The engine should still start even with low fuel pressure (mine started with about 30 psi and ran too). The best way to diagnose this problem is to hook up a fuel pressure gauge via a T connection in the feed line close to the engine.

[DABLACK]

You might be looking at a leaking injector (or several). Have you checked your fuel pressure? The engine should still start even with low fuel pressure (mine started with about 30 psi and ran too). The best way to diagnose this problem is to hook up a fuel pressure gauge via a T connection in the feed line close to the engine.

no i dont have a gauge.....is an injector thats faulty give that kind of problem hard to start in cold etc...

[Rus]

A faulty injector can leak when the engine is off and let down the pressure. This could lead to a delayed start later as well as some black smoke from having the engine flooded with fuel.

[DABLACK]

A faulty injector can leak when the engine is off and let down the pressure. This could lead to a delayed start later as well as some black smoke from having the engine flooded with fuel.


Rus, thank for your help by the way much appreciated. There was no black smoke...im miffed...:(

[nirvana19]

Could be the fuel pump or the fuel pump relay

[paanta]

Coolant temp sensor? Though mine have failed in a way that calls a hot engine cold, rather than a cold one hot...Either way, it's a quick check with a multimeter.

[Rus]

DABLACK,

I don't know where you're located, but if you have something similar to Advance Autoparts in your area, you can pick up one of these babies: http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_FUEL-PRESSURE-TESTER-Actron_9030328-P_N3388_T|GRP2018____

I got mine when I was having fuel issues and then picked up a t-connector at home depot. Its an easy to use setup because all you need to do is take off the feed line, attach the one end of the T to the feed hose, another to the gauge, and the third to a short piece of fuel tubing leading to the injector rail. After that you can monitor fuel pressure at any time.

Could you describe the issue in a little more detail please? Does this occur after the car sits for a certain amount of time? Does the behavior change with engine temperature? Ambient temperature? I experienced hard starts in my car for a while and eventually replaced the fuel pump, installed a check valve, replaced all injectors and also the FPR. Now the issue is nonexistent. My car would be hard to start after it sat for a long time or was parked facing up an incline. The condition was independent of engine or ambient temperatures.

[DABLACK]

DABLACK,

I don't know where you're located, but if you have something similar to Advance Autoparts in your area, you can pick up one of these babies: http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_FUEL-PRESSURE-TESTER-Actron_9030328-P_N3388_T|GRP2018____

I got mine when I was having fuel issues and then picked up a t-connector at home depot. Its an easy to use setup because all you need to do is take off the feed line, attach the one end of the T to the feed hose, another to the gauge, and the third to a short piece of fuel tubing leading to the injector rail. After that you can monitor fuel pressure at any time.

Could you describe the issue in a little more detail please? Does this occur after the car sits for a certain amount of time? Does the behavior change with engine temperature? Ambient temperature? I experienced hard starts in my car for a while and eventually replaced the fuel pump, installed a check valve, replaced all injectors and also the FPR. Now the issue is nonexistent. My car would be hard to start after it sat for a long time or was parked facing up an incline. The condition was independent of engine or ambient temperatures.


Well Rus I noticed when the temp dropped here in Toronto,(now you know where im at) a few times in the morning it was getting hard to start... long cranking to be excact. And getting worse. But when the car finally started and got up to running temp and if i shut it off re start was no prob. I get to work 10hrs later sitting in the cold hard to start. After investigating I came up with the check valve resoulution ordered it and installed it. Tried to start it the battery had died trying.... got a new one and now it wont start. I proceeded to then install a regulator... same result
So Rus here I am now driving the wife's E46 to work and getting questioned every day now if I drove the speed limit in her car. :)

[ahlem]

Do you have wet plugs?
Do you have spark?

[Rus]

Since the issue seems to be related to cold temperatures and doesn't manifest itself on a hot engine, it is probably not fuel-related. In my case, when fuel pressure bled off, the engine would start after maybe 4 or 5 seconds of cranking. Basically long enough for the pump to pressurize the system. This would also happen on a hot engine.

It may be worth a try to pull out the spark plugs and check the gaps, condition and color. It is not unheard of in colder climates for cars to not start with worn plugs (Russia comes to mind :-p ). In cold weather, having good spark to ignite the fuel mixture is pretty important. Also, it may be a failing crankshaft position sensor. Generally, they'll just outright not work when they fail, but I've heard of instances where they caused issues before causing a no-start. For the longest time my CPS was causing a hesitation when pulling away from a stop on a cold engine in the morning (diagnosed the CPS after it crapped out completely and was replaced). The new CPS has eliminated the hesitation, made the car catch much faster on start up and smoothed out the idle. If you have a multimeter, check the CPS as per the Bentley manual. Do it hot and cold to check for differences.

Also, if you want to double-check the fuel pressure issue, jump the pump relay and run it for a few seconds before cranking the car. If it starts faster, then its fuel.

Hope this helps :)

[DABLACK]

Could be the fuel pump or the fuel pump relay

does anyone have the part # for the fuel pump relay

[ahlem]

I'd try turning the ignition from off to fully energized but not far enough to crank several times at about 3 second intervals then try to start the car. I believe the fuel pump kicks in for about 2 seconds then shuts down. If you do it a couple times, you build fuel pressure. If it starts right up once you do this you have verified that the relay works OK and something is letting down fuel pressure when it sits. You can have a helper do the on-off manuever while you listen in the trunk for the two second fuel pump run. Cheap and painless check.

[DABLACK]

I'd try turning the ignition from off to fully energized but not far enough to crank several times at about 3 second intervals then try to start the car. I believe the fuel pump kicks in for about 2 seconds then shuts down. If you do it a couple times, you build fuel pressure. If it starts right up once you do this you have verified that the relay works OK and something is letting down fuel pressure when it sits. You can have a helper do the on-off manuever while you listen in the trunk for the two second fuel pump run. Cheap and painless check.

This is the technique I used when it was getting hard to start on very cold days after a while(turn the key 2 or 3 times to get pressure and it would start) then i installed the check valve and regulator and like i said now nuttin doin it wont start

[DABLACK]

This is the technique I used when it was getting hard to start on very cold days after a while(turn the key 2 or 3 times to get pressure and it would start) then i installed the check valve and regulator and like i said now nuttin doin it wont start


Well boys, I talked to my bro who was a Bimmer & Volvo tech he suggested all the same things you guys did but last night he said "as a shot in the dark I should pinch off the retun hose at the regulator and try to start it" i did this this morning and VOILA after a sputter and choke the son ova b**** started.
Any thoughts gentleman...now im wondering if im missing somthing. I read an earlier post that he installed the check valve as well and he didnt get his e34 going until 1-3 days later and hasn't looked back...but that still seemed odd
am i being too skeptical.....

[Rus]

Your FPR must be faulty and letting fuel through at all times. The way it should work is this:
Engine off - no vacuum - FPR valve closed and fuel retained in the injector rail.
Engine on at idle - high vacuum - FPR valve open, some fuel returned to tank
Engine under throttle - low or no vacuum - FPR valve partially open or closed, less or no fuel returned to tank.

If you pinched off the return line and the car started up, then the FPR is open all the time and when you tried to start it before, the pump couldn't build enough pressure in the system.

[DABLACK]

Your FPR must be faulty and letting fuel through at all times. The way it should work is this:
Engine off - no vacuum - FPR valve closed and fuel retained in the injector rail.
Engine on at idle - high vacuum - FPR valve open, some fuel returned to tank
Engine under throttle - low or no vacuum - FPR valve partially open or closed, less or no fuel returned to tank.

If you pinched off the return line and the car started up, then the FPR is open all the time and when you tried to start it before, the pump couldn't build enough pressure in the system.

FPR....i hoping you mean fuel pressure regulator...(im out of the loop with some terminology so I need to learn up on fancy code names;))...I got a new one on 2 days ago just in case...while I was eliminating some things after check valve, like relay's etc i got it pronto as my brother and you guys suggested and after that it still didnt wanna give until the ol pinch off technique
so I wanna make sure im not assuming the problem is solved and screw myself

and again thanks Rus and the rest of ya'll guys...ive been a long time reader here and picked up some no ALOT of help and tips and the main reason is all of the people here are just the best!!!!!!:D:D:D

[Rus]

Yes, FPR means fuel pressure regulator. If your car is starting up when you pinch the return line, something isn't right with the FPR. It should be doing the pinching, not you. You may have gotten a brand new faulty FPR. Stranger things have happened :-p I'm not sure if there's a way to test the FPR outside of making sure that it holds vacuum. You gotta realize that its up against about 60 psi of pressure and the smallest imperfection in the valve inside of it may cause it to leak. You could pull the little return line off of the FPR and then jump the fuel pump relay terminals to operate the pump to bring the system pressure up. Watch for fuel to come through the FPR. It shouldn't be siphoning fuel through when the engine is off. Be sure to use a rag to catch any fuel that comes out. Wouldn't want to spray the engine with gasoline.

[DABLACK]

Yes, FPR means fuel pressure regulator. If your car is starting up when you pinch the return line, something isn't right with the FPR. It should be doing the pinching, not you. You may have gotten a brand new faulty FPR. Stranger things have happened :-p I'm not sure if there's a way to test the FPR outside of making sure that it holds vacuum. You gotta realize that its up against about 60 psi of pressure and the smallest imperfection in the valve inside of it may cause it to leak. You could pull the little return line off of the FPR and then jump the fuel pump relay terminals to operate the pump to bring the system pressure up. Watch for fuel to come through the FPR. It shouldn't be siphoning fuel through when the engine is off. Be sure to use a rag to catch any fuel that comes out. Wouldn't want to spray the engine with gasoline.

I have started it successfully 3 times now without a hiccup since this morning....the real test will come tomorrow morning after 16-18 hrs of sitting overnight in the cold

[DABLACK]

I have started it successfully 3 times now without a hiccup since this morning....the real test will come tomorrow morning after 16-18 hrs of sitting overnight in the cold

Started like a charm this morning..I guess its fixed for now.... next job is spark plugs and looking at new/rebuilt injectors. Keeping an eye on some intresting posts for injectors...

[Rus]

So you're just going to leave the line pinched off? If so, its not fixed, you just figured out what the issue is. I'd be getting that new FPR replaced since its obviously not working.

[DABLACK]

So you're just going to leave the line pinched off? If so, its not fixed, you just figured out what the issue is. I'd be getting that new FPR replaced since its obviously not working.

No sorry Rus I only pinched it off to start it (my bro suggested if I clamped the line off with vise grips it should start but if I had to pinch off all the time to start it then there are problems!!!)...after it started I removed the vise grips and it ran just fine.The next day (today) after sitting over night I have started it without pinching off (10 times and a few short trips) and it has beeen turning over every time like clock work. I assume the FPR is good. It starts actually better than before.

[DABLACK]

No sorry Rus I only pinched it off to start it (my bro suggested if I clamped the line off with vise grips it should start but if I had to pinch off all the time to start it then there are problems!!!)...after it started I removed the vise grips and it ran just fine.The next day (today) after sitting over night I have started it without pinching off (10 times and a few short trips) and it has beeen turning over every time like clock work. I assume the FPR is good. It starts actually better than before.

well 2 days in a row a drive to and from work and Tues morn no start...damn it:(... im now thinking cps...where is it located and is it a fairly easy re & re

[Rus]

Have you tried the pinch trick again?

The CPS is located on the front right side of the engine. Follow the passenger side of the timing cover down and you'll bump into it. Takes about 10 minutes to change it. I believe its held on with one 6mm allen head bolt. The mount is adjustable using a 10 mm on the back of the CPS mount. Use this adjustment to set the airgap between the sensor and the timing wheel. Its a simple procedure once you remove the fan and route the wire properly. HTH