The first start of the day takes too long to fire up. The second start is normal if its done in under an hour or so it seems. So my question is what holds the pressure in the rail. The FPR was replaced a year ago as it was leaking with an aftermarket regulator ( standard motor products) from the rock as the OEM Bosch unit is now unobtainium . The fuel pump check valve was also replaced when the fuel filter was replaced as preventative maintenance . There is no fuel in the vacuum line of the FPR. It seems like the FPR has failed already.



Thank you

Hi,

From what you are saying with the two major components being changed, its easy to think about the only other outlets being four injectors causing a volume loss overnight. Plus additional mathematical odds in play.
With all the posts over the years the injectors have beat the odds a lot!
A bad injector, I will have to say, it’s not impossible.

A hot engine does away with any fresh fuel droplets can just evaporate.
So it’s recommended to preform the same pressure checks as to find the other component failures.
A pull them out onto a spread colored a paper, that will stain from a drip, is a test that might catch one.
Bump the engine a few times to Pressurize the rail and wait.
Pressure evaluation over time is one diagnostic procedure recommended.
Volume isn’t definitive enough without including quantities in a brief time period specification. This from the “white coat” laboratory boys! (:)

A test I use:
Try to bump the engine without actually cranking to fill the rail before actually starting in the morning, if I’m suspicious of a leak down, in all troubleshooting to if I can invoke an environment sequencing change.

Liquid Volumes can be the tricky thing to plug into an equation. Factors of replenishment were set by providing excess and recirculating. That abundance diminishes very slowly but inevitably.
Is it temperature changes, a leak down symptom or supply?
Can it be aged pumps or an electrical delay in pumping enough back in?
These are carbon brush motors and eventually age but Bosch pumps have seemed to go far longer than many of us expect them too.
Double check their reaction times to a “Call of Duty.”

Now with that normal stuff out of the way, we all can talk about, “How does the engine runs when first started?”
Does it stumble some until it gets fuel or just purrs right along?
Does it Rev above idle and right down and evenly with predictability?
When cold, any air leaks are more likely to be notice as an engine that is slow to get rich enough and start quickly. This can promote into a “thought” of fuel supply shortages when its lack of enough fuel enrichment. Very closely it’s the same thing!

If not, have you ever changed out the intake manifold gasket?

The 240’s came with nice gaskets but don’t last forever either.
I don’t care for the real thin Felpro Brand that appears available for our intakes. Weird?
I like the more substantial Victor Reinz.
They’re not distributed by “every mother’s uncle,” unfortunately. (:)
That’s what eventually killed GoodYear’s Quiet V belts.
Now owned by Continental under their “Elite” brand. Got to look carefully or you’ll get the next best Continental.
GoodYear Industrial brought on the Slanted teeth with a special rubber compound.
Continental bought in but not the GatorBack name. They know what they like as well!
Even WAHLER has been pinched a little by Borg Warner but at least they still date them, so I know they can or shall out last a Stant or Caloric with ease.

It seem harder to get good stuff. Not Covid-19 but economic evaluations.
The big parts stores are watching profit margins and inventory shelving to entice a less knowledgeable generation of consumers for the time being.
Lots of industrial game changers are twisting on this.

Then there’s big bucks to the shops and get those bottom line parts in their deal offerings.
I just shake my head, sadly, for those using those types of services.

Good mind teasing information, within our two directional postings, are always welcome but I do stray some? (:-)

Phil

The car runs fine once started.

I'm with Phil. Leaky injector(s).

If you can't measure the rail pressure, you might learn something if you pull the plugs after the engine cools. Use your nose. Or leave the plugs out until morning and test cranking time.

I think your long cranking might be due to flooding and not loss of residual rail pressure.

And Phil's test... I suggest bumping the pumps, not the engine. Jumper fuse 6 to 4 to run just the pumps instead of cranking. You'll easily prove the rail pressure is or isn't the issue. Once you've watched on a gauge how quickly the main pump brings pressure up in LH, you'll stop thinking about residual pressure being the issue on hard cold starts.
--
Art Benstein near Baltimore

From Rock Auto's newsletter:

I had been planning on replacing all of the brake lines on my Chevy Silverado for some time, but never got around to doing it. But after a weekend of hauling loads of wood, one of the rear brake lines blew out and forced me to take care of the delayed repair. Since I would be doing all the work anyway, I also decided to replace the front calipers.

I was rushing through the job and not paying much attention. Once I routed all the new lines and put on the new calipers, it was time to bleed everything. But during the bleeding procedure, I noticed I had a ton of fluid pressure in the rear calipers and almost none in the front. Also, the pedal was not getting firm. After about an hour of scratching my head and much colorful language, I discovered that I had routed the brake lines through the proportioning valve incorrectly. But, my story does not end there.

I rerouted the brake lines to the valve and tried bleeding the brakes again. My father and I bled the brakes over and over and over, but the pedal was just not getting firm. I had bled brakes before, but never have I had to bleed them as much as I was. I looked on forums, asked friends who had similar trucks and looked at my brake line routing again; nothing worked. I eventually surmised that it might be the ABS module needing an electronic scan tool to properly bleed. I did not have that type of tool, so I threw in the towel and took the truck to a nearby shop.

The next day I got a call from the mechanic...I could not believe what I had done. I had put the calipers on upside down and on the wrong sides! With the bleeder screws at the bottom of the calipers, no amount of bleeding would have removed the air bubbles from the brake fluid. I had to pay the mechanic $240 to fix my blunder! Do not make the same mistake that I did. Take your time and do not rush a repair.

Cody in New Hampshire

Thanks Art,
I will try just activating the pumps with out starting to see if it is a pressure loss in the rail. I do not have a ability right now to take the car out of service to remove the plugs and wait.

The vacuum line for the charcoal canister was cracked/split open in a few places and after repairing it starts fine. I will be removing and and capping it off on the throttle body. I would think at this point it no longer functions as intended and will just be causing more aggravation down the road.
Thank you for all your suggestions and comments.

Glad you got it working. I'm not familiar with the evap charcoal canister being associated with a notably delayed cold start. I'm curious why that would be.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Hi Dave , I think it was the large amount of un-metered air getting in. It actually caused a no- start problem and thats how I found the leaking vacuum line.

Along Art's train of thought, when starting first thing in the day, have someone watching the tail pipe. If the cylinders are that flooded I expect you should see an initial puff of black smoke. If you have a cold start injector on the intake manifold, don't discount that it could be leaking down the pressure.

Momentarily jumpering fuses 4 and 6 to prime the pump as Art suggests is easy to do. You can use a paper clip in one hand. (a paper clip in your car kit is good to pack for just such purposes). If you can start right away afterwards you know there's loss of pressure at the rail. If it starts perfectly normal then less likely to be leaking injectors, more likely the common FP regulator or pump check valve as you initially suspected. While jumping the fuses, if you listen underneath you can hear the main pump spin up. If there is loss of residual fuel pressure the pump noise may be more noticeable than when still pressurized with a warm engine.

I would expect if just one or two injectors are leaking you also would have an initial rough start after jumpering the pump. If you pull your plugs, be sure to read your plugs for differences. If you suspect the main injectors (or FP check valve) consider running a tank or two with a good injector cleaner to see if that helps improve things.

One way to check for a leaking regulator, in addition to sniffing the vacuum line for a leaking diaphragm, is to pull off the return line and stick a thimble underneath the outlet or use a short length of clear vinyl tubing pointed upward with a rag underneath to see if it collects gas overnight. The Standard FPR that Rock sells seemingly has a good reputation. IPD also sells it. FCPEuro has gone with Delphi. Pelican still lists the Bosch, although they're one of the few, so it may be just remnant stock on hand, not from a distributor, or an incorrect listing.

If none of that checks out, you may need to consider removing any cold start injector and then lifting the fuel rail for further inspection.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Hi Dave,
thanks for the info. I have been a faithful user of marvel mystery oil in the fuel for the last 10 yrs or so. I did get the car on the highway for a good run 90-100 mph for a few minutes and the next morning it started right up normally! But it did not last. I will go with a fuel system cleaner next tankful and run it through. This car does not have a cold start injector. No black smoke or residue in the tailpipe. Original intake manifold gasket with 256k on the clock. Injectors and main pump are original as well. I am the second owner. I did have to replace the tank last year as it rusted though on the top. So a new in-tank pump as well.

My garage is jammed with new cabinets and appliances for my new kitchen so I am limited as to what I can do right now.

Good Morning Art or on your time zone, a later one. (:)

You are an example of what I said in the ending of my post on the thread.
Your morning cup, of whatever your are having during the day, is brimming over with information for us Joe’s! (:)
You are our Rock Star!

The Rock Auto post was interesting too.
Any calipers can be swapped over and to be installed upside down must be really symmetrical.
You would think the mounting holes distances should have be shifted or something.
The reasoning behind bleed holes locations is going to be very vague to most people.
Same goes for all kinds of venting apparatus.
They are not there just to put something into a system conveniently. I.E. Master Cylinders, fuel tanks, radiators and other similar hydronic principled systems.
Even ice cubes are subjected to internal pressures under certain conditions.

I understand your procedure to jump the pumps and not cranking it to pressurize the rail.
But for many digging into a fuse panel is well beyond those who have no idea what happens past turning that key.
His sensing of a longer crank time eventually wakes up everyone to a different daytime reality.
If you hang out around some tire shops, while getting tires I hope, you might observe some ferociously worn out rotors. I did many years ago.
I saw at least two very deep rounding grooves that waved like an ocean swell while going across the surfaces.
Steel pads against cast iron is not a pretty sight let alone the sound they must have made? Either unbelievable.
I cannot imagine the lack of stopping power but it made it onto the lift with no injuries. No time to be in front of that car!

The idea of taking the plugs out after pressurization would create a nice aromatic atmosphere the next morning.
I’m not so sure that my nose would be so discerning to know which cylinder or injector though.
Maybe seeing a paper towel or plastic that was tied in front of the holes might help, if working alone.
For sure the smell of any one of them leaking that would be too much.

A draining injector can not be dismissed or the likelihood of calipers fitted upside down and backwards apparently.

I recently corrected my 24 space collet indexing fixture.
It was purchased long ago for very reasonably price new. That merchant is now out of business.
I think I found out why.

I had not used very much except on round stuff so it was fine.
When was slotting and pinning a piece of hex stock for a handle so I used a three jaw chuck adapter.
The flats of the part did not line up flat to my table top because something was crooked.
One chuck jaw did not Not zeroed out straight up and down.
I discovered that a keying pin for the locating the collets was drilled off center so threw off the collets to the index plate.
About .100 off center.
This amounted to a 4 degree 12 second error in relationship to all axis’s of the machine depending on how fixture was use.
In round work, say in bolt circles I had not noticed it. As long as any work done was “inclusive” to its rotational basis only no one would know, including me!
But alignment to other external planes or things aligned correctly to a standard that I expect to have.
So, I got a nice surprise!

It was nice to know though that my intuition or skills of many years of machining are still awake!
Abate, I have slowed down so much it takes me 30 minutes to do a ten minute job.
Don’t ask how it takes to do a post!

Phil