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Discussion Starter #21
Had another person help to turn the key on & off.
Using both inline & fuel rail gauges, neither is accurate but are consistent & don't leak.

Turn On No Return Line Pinch:
Inline gauge bouncy reading is only 5-10lbs while the fuel pump runs then falls to zero when the fuel pump shuts off. Same for fuel rail gauge but about 10lbs more.
Turn Key Off
Turn On with Return Line Pinched: Same result.

As inline gauge reads 25lbs consistently with engine running going to remove it and retry.
 

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What is Static (Key On/Engine Off or Engine Running and FPR Hose Disconnected and Plugged) Fuel Pressure supposed to be on a 2.5L Flex Fuel engine?
 

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Discussion Starter #23
Did a lot & screwed up, again.
As I remember static is supposed to be 55lbs but I'll have to check to be sure.
What I did remember was I have a known good Bosch FPR so swapped it.
What I can't remember is where I put one of the [email protected]#$%^ FPR nuts. Crap!
Didn't drop it, I literally put it somewhere. It's a flanged nut & I don't have those. Searched for 3 hrs. After dinner I'll see if there's another nut on the car like it, if not I'll have to make the dangerous trip to the hardware store.
 

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So the Flex Fuel 2.5L Engine operates at the same PSI as the turbo cars...
If that is correct and you were reading 25 PSI with the engine running...
With the engine running "deadhead" the pump by momentarily pinching off the return line, the pressure should immediately rise to "max output", I have a Walbro 190 installed and when I deadhead the pump the pressure immediately pegs my gauge at 100 PSI.
If you are not immediately getting to a minimum of 80 PSI then there is a problem with a restriction in the fuel feed circuit or a problem with the pump or hanger assembly.

As far as that dangerous trip to the hardware store, use common sense...
This is what I do during my Bi-Weekly trip to Walmart during Senior Hour.
Mask Up, Take Disinfectant Wipes and Hand Sanitizer, Do Not Touch Your Face, Wipe Down Everything You Touch Upon Leaving and use Hand Sanitizer before Touching Your Keys, Door Handle, Steering Wheel, Phone, Clean the Product You Purchased (Lysol Spray for Large Items) and Wash Your Hands Immediately After Arriving Home and Disposing of the Bag.
 

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Discussion Starter #25
Long work day.
Possible bigger problem then thought or multiple problems. Pinched return line while running & fuel pressure immediately dropped to zero. Didn't think that was possible and kept checking it actually was the return line. Same result after swapping to backup fuel pressure regulator (see below). Again, I don't trust this gauge but I don't think it's that bad. May have to put this on the back burner until new gauges get here and with slowed shipping that could take a while.

Meanwhile.
Never found the lost nut however thought of a better alternative, replace both with connector nuts. I've used connector nuts on other areas. Don't know if anyones posted this suggestion but it makes things waaay easier except standing 45min in line to get into the hardware store to spend less than $2.
FPR's bottom nut is extremely difficult to get on or off but easy to lose. I ground down a socket to get in the tight space, even then it takes too long & still a major risk of dropping the nut. I got two 10/32 pitch connector nuts and fender washers. The fender washer isn't the match to 10/32 but 2-3 sizes smaller (smaller than a dime) to fit the FPR properly. You also have to drill the washer's hole bigger to get over the fuel rail bolt. For absolute safety I also installed an external spring steel lock washer between the fender washer & connector nut. A small dab of E6000 glue or silicone into one end of the connector nut to keep dirt out. I removed a small portion off the bottom of FPR bracket's hole so it looks like a horse shoe. By removing the top nut and just loosening the bottom allows the FPR to be pulled forward until it's out of the rail. Tilting the top slightly forward allows the FPR to be removed without removing the bottom nut and risking nut and/or washers disappearing. However, I had to remove bottom nut & washers to get the FPR back on, too tight a tolerance. Still much faster, a complete swap in under 15 minutes, with my glasses & headlamp of course. The connector nut is 8mm – 5/16 and a little ratchet wrench loosens them fast to then allow fingers for a faster finish. Very nice! Bonus, if necessary you can use a regular wrench or even a small crescent wrench. Photo only shows example for bottom.
Future Bob will be happy about this.

Take care, DDBob.

270306
 

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Discussion Starter #27
UUUG!

What am I doing wrong?
or
Is it possible the little schrader valve in the fuel rail test port is not opening completely?

As I'll be waiting a long time for the Glowshift FP gauge I bought 2 fuel certified gauges from the hardware store. One cheap $5 small in line and one for the fuel rail about 3 ½ inches ($18). Now what's driving me crazy. Please note; 1) there was no gas leaking during testing, 2) FP held after shut down for 20 minutes when I released it and 3) deadhead test caused FP to go up over 20 lbs in less than 2 seconds when I then released it.

* New cheap little in line gauge reads the same as the previous Marshall gauge, 42-44lbs (11-13lbs below 55-57lb spec). New rail gauge read 41-42lbs, pretty close to the in line. Put old Marshall in line back on & kept new rail and same result, 42-44 & 41-42lbs. Thought I was on the right track. Wrong.

Swapped to old rail gauge that read 25lbs and it still did, old in line Marshall still 42-44lbs. Old rail gauge must be bad, right? Maybe not.

Swapped back to new rail gauge and surprise, it now reads 25lbs while the old in line Marshall was still at 42-44lbs.


Detached then reattached rail gauge. Same result. Detached and disassembled hose to make sure nothing was clogged. Everything OK. Reassembled & tested, new rail gauge still 25lbs but noticed if I move the hose to where it started to kink the pressure rose a few lbs. Don't know if that's relevant. Detached and disassembled hose and replaced with longer hose so I could move the gauge around. Same result.

After walking away cursing this nightmare, a few hours later I thought, "Is it possible the little schrader valve in the fuel rail test port is damaged or not opening completely? Could it be that simple?"
The rail gauge connector I'm using is a SnapOn and no gas was leaking. Will try this again tomorrow but would appreciate your expert opinion.
Also, if I have to replace the fuel rail schrader valve is it Chrysler specific or are they all the same? Assume it's not normal rubber but a fuel resistant material.

DDBob going crazy.
 

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It is very possible that the schrader valve is not opening completely, also be sure the pintle/tab in the gauge hose is pushing completely down on the schrader valve.
Originally I used the schrader valve for an R-12 A/C system and if in a pinch I will use a schrader valve for a tire.
I have had schrader valves leak over the years, usually nothing major, just a smell of fuel, remove the cap and see its a little wet and then I replace it with whatever I happen to have.
I have schrader valves in my toolbox and not sure where they came from, probably tires.
If you have a compression tester there is also a schrader valve in that hose.

If it is driving you nuts and you need/want a fuel pressure gauge...

Give them a call and see how long to ship, I bought from them numerous times when I was still a tech or needed something for my car (OTC Cylinder Balance Tester, MityVac Vacuum/Pressure Tester)

I also found this...

 

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Fuel pressure gauges use a very low tension schrader valve. It most definitely is far lower than a typical schrader valve you'll find for valve stems for tires. Some of the better quality leakdown and compression test kits will come with spare schrader valves. Some will actually tell you this in compression test instructions/directions. If you suspect this may be your issue, you can remove the schrader valves temporarily and recheck pressures.
I have also noticed over the years working on this vintage of Chrysler is that the cap for the schrader valve on the fuel rail has some rubber stuffed into the far end of it. Used to keep schrader valve clean from dust. NAJ mentioned seeing wet fuel in cap. What I have found is it wasn't so much the schrader valve leaking as it was starting to crack open from the rubber swelling so much inside the cap! The rubber itself was starting to depress the pintle on the schrader valve!
Found this many many times while diagnosing faint fuel smells from under hood. Removing or reducing swelled rubber inside cap fixed the issue.
 

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Discussion Starter #30
Thanks guys.
Removed valve stem pental & it had 1-2 drops of gas but the safety cap kept it from leaking out. Cap's rubber seal has a deep depression to allow the pin into. The pin was slightly bent and it all looked pretty ragged Took a pental from a tire stem and was surprised it's tiny ring seal wasn't rubber but some form of hard plastic similar to the original. To be safe I ordered a new high temp 450 degree pental from DieselORings.com.

With the pental out I attached the new fuel rail gauge and tested. “Started off” with the same results reading 25lbs while the inline gauge reads 45lbs. So it wasn't a pental problem. I'm starting to question myself, am I missing something, both should read the same right? Also did the 3 fuel line pinch tests (in, out & both) and all caused FP to quickly shoot up. This caused the new rail gauge to go up to 55lbs & stay in a 2 lb range after un-pinching. Pinched & released again and it went up to 65 and stayed. Inline still reads 45-47lbs. Eagerly await the OTC gauge.

FYI:
  • I confirmed that my 2 FPR's are speced at 55lbs.
  • Replaced my fuel pump about 8 years ago with a Walbro 255 from FWDPerformance.com
 

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Until you get your "New, Known Good" gauge there is really nothing that you can do since you have no idea if either gauge is reading correctly.
Chrysler says if fuel pressure is reading low they want you to place the gauge in front of the fuel filter and retest but then of course you need the adapter to place in the line.
If pressure is low, replace the fuel filter, if it is still low be sure there are no restrictions in the fuel feed line from the tank to the fuel rail, if none are found remove the pump hanger and see if there is an issue with the hose on the hanger or the clamps.
If there is an issue with the hose be sure to use a Submersible Fuel Hose.
My Walbro has been in the car for 13 years and pegs my gauge at 100 PSI instantly when pinching the return line.
 

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Found this when chasing down a fuel problem in my friends autocross GLHT. Tank sock filter was fubar, and pump ingested one of the rubber feet that the fuel pump assembly rests on inside the tank. Look closely at fuel inlet in photo. Lucky owner had enough common sense to put the car on the trailer before he blew engine up from running so lean.
 

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Discussion Starter #33
Hope my Walbro fuel pump doesn't look like that as it's only about 7 years old.

Managed to borrow a cheap FP rail tester & it actually worked! Both the little inline Marshall and cheap rail tester read 45-47lbs, went up & down with rpm increase/decrease, gauges immediately maxed with the return line pinched, after shut down pressure held for more than 10 minutes when I disconnected and most importantly all readings matched. Repeated the test 3 times with the same results. Finally consistency. Feels good to make some progress! But, if a leaky injector wouldn't the FP fall quickly after shutdown?

OK, FP is confirmed low.
  • Momentarily removed the FPR's vacuum line & FP jumped up about 10 lbs to 57lbs. Writing this I realize I didn't think to try & hook up my vacuum tester pump/gauge to that line to see if it was low but don't know what it's supposed be anyway. Will try tomorrow.
  • As both FPRs resulted in the same readings I would assume they're good but ya never know. Any way to test with a vacuum pump/gauge?
  • Checked fuel line from the rail to the gas tank and everything looked healthy.
  • Chrysler said to check FP in front of the filter? If that's between the filter and fuel rail that would have the same readings as the little inline & rail gauge. Shouldn't it be checked between the tank and filter? If the filter was clogged wouldn't it act like a valve keeping high pressure between the tank & filter then reducing pressure between the filter and fuel rail? Not a big deal as I'm pretty sure the kit has the necessary connectors, just don't want to do unnecessary work.
DDBob
 

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Sounds like fuel system is absolutely in perfect working order. The 55 PSI is static pressure, meaning no vacuum or pressure is being applied to regulator. 45-47 PSI with engine running is exactly what it should be (vacuum/pressure line attached). Fuel pressure slowly decreasing after shut off is more likely check valve in fuel pump weeping than injector. Many seem to do this. I would call that completely normal. Abnormal would be to maintain full pressure at rail indefinitely after shutdown.
I think you really are chasing a ghost (lol). Unless your getting flooding issue (very hard hot restart), fuel smell in oil, running on two or three cylinders on hot restart, your injectors are probably working perfect.
 

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Multi-Port Fuel Injection measures Total Fuel Pressure across the tip of the injector since the injector is exposed to manifold vacuum/pressure it is a combination of push (rail pressure) and pull (engine vacuum)
The Static Fuel Pressure reading at the rail is the pressure that will be maintained across the tip of the injector.
2" HG = 1 PSI, if static pressure reads 55 PSI and you start the car and have 18" HG in the manifold rail pressure will drop 9 PSI so rail pressure will now read 46 PSI.
46 PSI + 18" HG = 55 PSI across the tip of the injector.
Rail pressure constantly changes according to engine load (as vacuum increases/decreases) so the FPR is constantly moving.
On a turbo car the FPR also allows rail pressure to increase above static, every 1 lb of boost = an increase of 1 PSI of rail pressure, at 12 lbs of boost with a static reading of 55 PSI rail pressure will read 67 PSI, that is why the pressure needs to react instantly to changing load conditions.

Yes, Chrysler says if rail pressure is low check pressure "before" the filter to verify the filter is not restricted, that is why I said just replace the filter, its easier.

Fuel pressure bleed is normal on all cars but over time, not immediately.
That is why the ASD is actuated for 1 second with initial key on to pressurize the fuel rail.

 

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Discussion Starter #36
May have found the ghost, much worse, crap!

Didn't reply sooner because wanted more info.

Good Part: Did all the FP and vacuum testing prescribed and everything was good. Static ASD activation by grounded test socket or Key On is 57lbs, idle 47, pinched fuel line pegs gauges instantly. Vacuum is about 19lbs and goes up and down while revving engine & driving.


Bad Part: Re-examining the oil dipstick & cap there appeared to be a tiny amount of foam/water. As it was 2 months past it's 6 month oil change time (still only about 2,000 miles) I ran cleaner, let drip overnight then new synthetic & filter (always used Mobil 1). Old oil looked dirty but nothing unusual. Drove 10 miles, examined cap & stick and a tiny amount of foam is back. It must be leaking a very small amount of coolant because it doesn't appear to smoke on startup.

I'll try to borrow my brothers SnapOn cylinder compression tester & radiator tester tonight. I didn't notice the water drop because the plastic heater valve leaks a few drops through the valve control arm.

Is it possible re-torquing the head could fix this? If so aren't Chrysler head bolts a one & done product as if you re-torque they stretch so would have to install ARP head bolts?

DDBob.
 

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Good Luck,
The OEM headbolt can be reused BUT the FSM describes the maximum stretch.
#4
Myth #4 "headbolts have to be thrown away every time you use them"

Answer- Maybe.

Mopar specifies that headbolts SHOULD be replaced if they have been used twice. I have found a simple way to test headbolts and its never failed me yet. First step is to throw out any bolt that looks stretched or has some corrosion on it. Then you install the bolts using the procedure in the factory service manual, then stop before the last step.

The last step is to turn the bolt a 1/4 turn from the last torque reading (65 ft/lbs for an 11mm headbolt) set your torque wrench to 100 ft/lbs and do your 1/4 turn. If the bolt is good you should have no problem getting that reading before you hit the 1/4 mark, if a bolt is bad it won't come up to the 100 ft/lb mark. Just replace that one and continue on to the rest of the bolts.. I mention this little test of mine because I know most FWD Mopar racers have a bucket of bolts lying around from engines that have been striped, so spares 9 times out of 10 usually aren't a problem...
 

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Replacing head bolts is cheap insurance.
A compression test will only show a faulty head gasket if the gasket is blown out between two cylinders.
You need to run a Cylinder Leakdown Test to determine if the gasket is leaking at the water jacket.
If there is exhaust gases in the coolant you can use the pressure tester.
Install the tester, do not apply pressure, start the car, pressure should build slowly as the coolant expands, if it builds quickly there are exhaust gases present.
You can also use a Block Tester to check for exhaust gases.
White sludge is normal if the car is not driven for long periods of time or not allowed to reach operating temp when it is running.
 

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Discussion Starter #39
Update.

Did the blue chemical block test twice & it stayed blue both times.

Hopefully tomorrow night I'll get testers for leak-down, radiator pressure & because we have one a cylinder compression. If all test good then I'll be back at square one.

Drove it yesterday about 15 miles including up & down a few big hills. No overheating & no foam on oil cap but some dis-colorization on the dipstick. Strangely not on the stick's tip but about a 2 inch area about where the block meets the oil pan. Examining that spot under a magnifying lamp there's a small amount of corrosion there. Whatever it is it's been there a long time. First thought the dipstick tube was lose but it's tight. Even if lose there's no outer water leak so it can't enter there. DDBob.
 

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Discussion Starter #40
Thanks for your help but I'm so screwed. Tuesday April 28th 2020

UV chemical dye in radiator & drove 20 miles. Should've done this first.
Result: No overheating or foam but fluorescent dye in oil and visually on piston tops in cylinders 1 & 2, much worse on cylinder 1. Also noticed a lot of black ashy carbon 3&4 that after SeaFoam shouldn't be there. From all this I knew at least the head gasket's bad but did compression & leak down tests anyway. It's been 8 years since the last compression test and there's too big a difference for an engine that wasn't abused.

* Compression Tests
Cylinder 1 2 3 4
Cylinder Firing Order 1 3 2 4


8-6-2012 DRY 132 132 129 136
WET 142 140 140 142

4-28-2020 DRY 118 124 113 118
WET 141 125 125 140
* Leak Down: Dip Stick Y Y N Y
Test Oil Fill Cap Y Y Slight Y
PVC Y Y N Y
Radiator Y Maybe N N
Exhaust Pipe N Slight Y Slight
Throttle Body N N N N

Air leaked into the radiator super fast on cylinder 1.

Thought leak down on cylinder 3 was very strange. Leaked down so quickly I thought the piston wasn't at TDC. Checked and ran test 3 times to make certain. Because of that and 3's compression is lower than the others my theory it has a bad exhaust valve.

Again, so screwed. Decision time on the Daytona's future. Will let you know.
DDBob.
 
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