Thanks for everyone's input. I've already found a strong fuel odor in my regulator's vacuum line. It is leaking and probably the bad guy in my situation. This strikes me as a conclusive test for a bad regulator as was recommended earlier and in other posts. The regulator check took me only a couple of minutes and is a very easy test.
Is there any need to go to all this extra trouble with the fuel pressure gauge? Compared to the checking FPR vacuum line, the fuel pressure test is complex and prone to problems. I'm good with my hands, but I'm not a mechanic. It takes a long time too. I would rather pull the plugs after leaving it overnight and sniff for leaking injectors. Fairly fast and no need for me to get any new equipment. I can do it right now and it involves very little that can go wrong. It also seems to be a sure test for leaking injectors.
In any case, I'm waiting on a new regulator now and will fix it when it arrives. A new (blue) coolant temperature sensor too to be safe. I'll post my results with the non-starting issue once I get these things taken care of and have a chance to test the car. Thanks everybody and I hope my trials prove useful to others experiencing similar issues.
Be sure to change out one item at a time so you'll know what helps or doesn't.
If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue
Symptoms of a Bad Fuel Pressure Regulator
If your fuel pressure regulator is going bad, your car could display several different symptoms. This article lists and explains the most common of these. Get your bad fuel pressure regulator checked if you notice any of the following.
Spark Plugs Blackened
Remove a spark plug and examine the end of it. If it is sooty, it could be a sign of a bad fuel pressure regulator. If you find a plug in this condition, check the rest of them. A sooty spark plug could just mean the engine is burning oil at that head.
If you end up replacing your fuel pressure regulator, you might also want to replace your plugs. They could be fouled out from the bad fuel pressure regulator. You can try simply cleaning them and putting them back, but if your engine still runs poorly, get new ones.
The Engine Doesn't Run Smoothly
Speaking of poor engine performance, if you are idling the engine and it is not running smoothly, change your oil filter and check your pressure regulator to repair bad fuel pressure. Another sign that your engine is suffering the effects of a bad fuel pressure regulator is if you have trouble starting the car. It will fail to turn over a few times before it actually starts.
The Tail Pipe Emits Black Smoke
Having black smoke coming out of your tail pipe is a sure sign there is something wrong with your fuel pressure regulator. Replace it. The normal color of any smoke coming out of the exhaust should be white or gray, not black, so if you see the latter, there is definitely something wrong.
The Dipstick Smells of Gasoline
Check the oil dipstick and see if you smell fuel on it. If you do, it could be a symptom of a bad fuel pressure regulator, which has allowed gasoline to leak into the oil system.
Engine Stalls
If the engine stalls when you press down on the gas pedal, check the fuel pressure regulator. There shouldn't be any hesitation when you press on the gas. Even if you only notice a little hesitation, get your pressure regulator checked out because it may just be starting to go bad.
Gasoline Is in the Vacuum Hose
If you are noticing any of the signs above, but aren't convinced that the cause is a bad fuel pressure regulator, there is something you can do to be sure one way or the other. Remove the vacuum hose that attaches to the fuel pressure regulator, making sure the engine isn't running. If gas is in the line, your fuel pressure regulator is bad. Also, if there is none in the line, but, when you turn the switch on, fuel drips out of the hose, it is bad. copied from DIY dot com
Testing for a leaking, ruptured, fuel pressure regulator diaphragm
that is a good analysis. How to verify the cause of an intermittent long crank and a start/stall condition. No need to have the electronics, just remove the vacuum hose and sniff if there is fuel smell or even fuel coming out. Watch for fuel. Takes over a minute that fuel is coming out of the port, diaphragm cracked. https://www.youtube.com/watch?v=AKtR_yF7bi8
Last edited by shogun; 02-17-2017 at 09:37 AM.
Shogun tricks and tips for the E32 series are HERE!
Quick update...I changed the (blue) coolant temperature sensor and the (black) coolant gauge sensor, but encountered the no-start condition earlier today. As a fun note, both sensors were original to the car (7/94) and I don't feel bad for changing them.
Next, I will be swapping out the fuel pressure regulator (vacuum tube smells like gas). I am a bit intimidated by pulling the injectors (with the rail) and also somewhat nervous about the snap ring on the FPR (especially putting it back on), but I will take my time and proceed with care. To this end, I picked up an internal/external snap ring pliers to make sure that I have the right tool. Any tips on the FPR swap would be greatly appreciated....
BTW -- In addition to the two coolant sensors, I installed a new fan clutch (sachs), new OEM fan shroud, new OEM fan and new OEM coolant level sensor. All of which needed change or were otherwise due for a change, and which compliment the new water pump, thermostat and just about every coolant hose that were done a couple of months ago as part of the head repair. It is very nice not to see the coolant level warning on the dash when I know that the expansion tank has the proper amount of coolant...yeah. Additionally, I replaced the aux fan, which was not working on either speed, but now works as it is supposed to... Finally, I bled the cooling system, which went smoothly as I had the front end up on race ramps.
The engine on the 525it is extremely strong at 255k miles and the temperature gauge is rock solid at 12 o'clock. I am enjoying the heck out of the car and generally go for it, rather than my e46 touring.
Last edited by squirrelhill; 02-18-2017 at 06:15 PM.
By way of some quick cliffs.... I was experiencing periodic no-starts on my 1995 e34 525it. The condition was occurring when the car was cold and usually happened after it was sitting overnight or longer. The car would crank, but would not catch. As a crude solution, I was able to pull the fuel pump fuse and crank the car a couple of times, then put the fuse back in, and the car would start on the first crank. As others noted, this was a pretty clear sign of a flooding condition. It also warrants noting, that the vacuum hose on my fuel pressure regulator smelled like gas, which is a clear sign of a bad diaphragm that could certainly cause the car to flood after sitting for a period of time.
In an attempt to remedy the no-starts, I first changed the (blue) coolant temperature sensor. While this seems to work in some cases, it did not fix my no-starts, which occurred the very next morning. After some hesitation, I gathered the courage to change the FPR. Good news...the new FPR seemed to have fixed my problem and I have not had another no-start in almost a week.... I am cautiously optimistic that the new FPR did the trick, but will provide another update if this is not the case.
For some more good news, I reset the motors on my dual sunroof and all is well. I am planning to clean out the drains and to lube the track this weekend to keep her in good working order. Such a cool function, especially with a car that starts as it should.
I hope that my experience, especially the valuable insights from several of the senior members, will help someone else down the road. I also want to thank Richard81 who helped me through the process via PMs -- your help was invaluable.
Last edited by squirrelhill; 02-25-2017 at 10:15 AM.
Great news that it is sorted. Thanks for the follow up with the solution which will help others.
Sorry for the earlier noise.
If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue
Thanks for the feedback, I added in the thread title SOLVED, so all know they can find the answer then.
BTW: my post # 3 was: First of all remove the vacuum hose from the fuel pressure regulator. If there is fuel inside or it smells like fuel, the diaphragm is cracked of the FPR.
Last edited by shogun; 02-26-2017 at 09:08 AM. Reason: typo corrected
Shogun tricks and tips for the E32 series are HERE!
1996 332IS
Built 3.2
CES/Steed TS Precision 6466, spraying a "$π!℅" load of meth.
Technique Tuning 80# tune.
1/4 mile 10.84 @ 136.72
Your 1 and only stop for all your BMW performance needs
WWW.CESMOTORSPORT.COM
Shogun is awesome. He supply's invaluable info to the E34 and E38 forums, and is always spot. A real wealth of knowledge. Thanks for everything you do for the community Shogun.
"**if you suck at driving, it certainly could put you into a curb. Don't suck."
Sniffing the open air not engough. Smells are not easy to tell. Pull the hose and spray perfume or bodyspray into it a bunch. I'm sure you have spray in your glove compartment. Then reconnect run the engine a minute or drive about. Shut down and pull the hose a few hours later to smell. If you can still smell perfume, you've got no gas or too little gas leaking to matter.
^^^^^^^^^^
Too bad "Andrew" is gone(?)this might have been an amusing discussion.
Last edited by ross1; 02-26-2017 at 08:32 AM.
If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue
Last edited by Butters Stoch; 02-26-2017 at 09:26 AM.
1996 332IS
Built 3.2
CES/Steed TS Precision 6466, spraying a "$π!℅" load of meth.
Technique Tuning 80# tune.
1/4 mile 10.84 @ 136.72
Your 1 and only stop for all your BMW performance needs
WWW.CESMOTORSPORT.COM
The moderator has a stake house?
demet
1996 332IS
Built 3.2
CES/Steed TS Precision 6466, spraying a "$π!℅" load of meth.
Technique Tuning 80# tune.
1/4 mile 10.84 @ 136.72
Your 1 and only stop for all your BMW performance needs
WWW.CESMOTORSPORT.COM
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