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Discussion Starter #1
Tuesday, March 24th 2020

Here's my social distancing project. Hoping you can help.

Chasing a ghost the last few months. Bad injector?

My 87 Daytona Z has a transplanted 2.5 turbo flex-fuel engine with slightly bigger Bosch injectors from a 93/94 Spirit / Acclaim. I'm thinking being this old the pintle contact surfaces may be worn but don't want to throw away money. However, in case I'm right, fuel injectors are re-manufactured so what's the opinion on the best source???


SYMPTOMS
A few months ago, only on startup, it began running very rough for 5-15 seconds then cleans out. Such a short time makes it impossible to test while running. Under heavy acceleration, it's a little rough at certain rpms. It's also lost about 2 ½ mpg but other than that seems OK. Weirdly, maybe every 6 startups it starts fine.

THEORY
I'm no expert but after lots of testing (details below) may be a fuel injector isn't fully closing??? After shut down gas would leak out, puddle and temporarily flood the intake on startup (rough running) then would continuing to run slightly rich (lowering mpg). When starting properly maybe the leaking injector was on the open head intake valve and the gas went directly into that one cylinder so it would only be rich for a few piston strokes?

WHAT I'VE DONE
  • No error codes
  • No gas around fuel injectors so assume seals are tight
  • Ran 2 bottles of Seafoam in 4 tanks of gas (no difference).
  • Sprayed carb cleaner into the intake (spotless before spraying), no difference.
  • Used my homemade smoke machine to test for vacuum leaks then a vacuum gun, no leaks.
  • Battery (12.4V) & alternator running (14.6V)
  • Swapped ignition coil, no difference
  • Injector connectors clean and tight
  • No bare wires in injector harness
  • Injector voltages are good and LED test light flickers.
  • Ground wires good: Stock fuel rail & intake manifold ground wires good but cleaned them anyway. Also has the FWDPerformance 4 sectioned 4 gauge ground wire kit modified to use much larger screws & bolts to different frame locations. Additional homemade fuel rail and alternator housing ground wires. All grounds & sockets cleaned or replaced throughout the car with several other additional grounds added. From past painful & very expensive lessons I'm a big believer in good electrical grounding & cooling esp in Chrysler products. FYI: Corroded sockets and/or bad grounds will dramatically slow-down turn signal frequency.
That's it. I'm stumped. o_O

If required, replacing injectors looks simple but very involved. Any trick way to do it rather than removing the entire fuel rail?

Thanks for your help.
Stay safe, DDBob.
 

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Great info, BTW. What you propose is possible, to test, you can use a fuel pressure gauge to verify that the rail pressure stays constant and does not drop after the engine is turned off. If not when the key is turn on the fuel pump for 1 second. If the pressure is high in the line the pump won't turn on. If you turn the key on then off, each time it is on it will turn the pump on for 1 second if the pressure in the fuel line is low. This will only happen 3 times when the engine is not cranked.
So I use these fuel cycles to gauge the pressure in fuel line before I bought a fuel pressure gauge.
 

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Discussion Starter #5
Thanks, everyone. Because we're pretty much quarantined here in Puget Sound I've got time & am saving some gas money.


Oh yes, it smells rich on startup.


I have an FP tester but it doesn't include the goofy Dodge adapter & have never found anybody that sells them. I borrow the SnapOn kit adapter from my brother but he's not around for another few days. Did the key dance twice, 15 seconds after engine shutdown, and the fuel pump does kick on as described.


I can make a pulse tester pretty EZ (couple of schematics online) but seems almost pointless now as everything indicates a leaky injector. However, I will wait to buy injectors until after doing a true fuel rail test with the SnapOn adapter. Besides, could die from C19 & would've just wasted my time on this. Really hoped to avoid tearing everything apart. This brings me back to some original questions.


Are there any hacks/tricks to make removing the fuel rail easier?


Anything I should avoid or look out for?


What shops sell the best re-manufactured Bosch? I've been told injector repair kits are a waste of time, effort & money on injectors this old.





Tearing everything apart to replace injectors I'm thinking it might be smart to bite the bullet & spend the money for a fancy fuel rail, pressure gauge and adjustable pressure regulator. TurboUnleashed has a kit for $215 but no gauge, think I've got one somewhere. Any suggestions? Searched Turbododge for used parts but nothing. I hate spending money but painful experience has proven gauges and adjust-ability is critical to keeping an old vehicle on the road. I've seen some of the DIY projects on stock rails but don't trust my welding skills.


Help is always appreciated.


Sincerely, DDBob.





FYI: I have several Mods I've not seen anyone else use that possibly you or someone else might find helpful. I have 3 pics posted on my album of relatively easy aerodynamic mods I made. Aero was a hobby since I was a teenager. Cost was about $35 but another $10 to mount the little trashed Chevy truck front spoiler found in the ditch (fast removal with R pins). I have more pics but can't figure out how to upload them. Maybe 3 is all I get. I believe my 87 Daytona was and may still be the most aerodynamic out there other than the old factory racers and a few salt flat racers. The front end mods dramatically reduced road air noise and provided a massive rammed air increase to the radiator and intake. Rear mods got completely crunched in a wreck and I was never motivated to replace them or continue upgrading. Before the crunch, change to crappy tires & possible fuel injector leak I would consistently get 23mpg mix, 38mpg highway at 55-60mph, occasionally 41 and once 44mpg. Those measurements were made after reaching highway speed, accelerating this engine always sucked fuel, pretty much flat ground, probably had a 10 mph tail wind and at least 70 degree weather. Aero works even for an old 2.5.





Others have found these mods very helpful after adapting them to their vehicles.


Every required repair I try to do it for future Bob, old Bob, feeble broken down poor Bob. It may take longer now but future Bob can do it in record time, less money, without physical injury or too much cursing. These simple mods allow removing my stock appearing tail light access panel and 2 piece plastic cover in front of the radiator in less than a second each. Others allow replacing my engine bay Power Module computer in under 1 ½ minutes (set record on 3rd try at 1 minute 20 seconds, fast enough) and interior Control Module computer in under 1 minute. Of course these times are totally dependent on me wearing glasses, being warm, knee pads and using a good head lamp.
 

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My experience with an Adjustable Fuel Pressure Regulator was not a good one, IMO, if the car is stock leave the OE in there.

As far as a fuel pressure gauge, back about 12 years ago I was having intermittent issues so I installed an electric fuel pressure gauge, still working fine.


1st Pic Fuel Pressure Sensor Underhood
2nd/3rd Pics Fuel Pressure Gauge On Dash (the smaller of the two)
 

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If it smells rich and no smoke then could very well be leaky inj's and fuel pr gauge may give indication on how fast it loses pressure after shut down.

To test we just pull rail and crank mtr with cardboard and watch pattern of inj's and make sure no drip. Can be messy if you don't cover all the bases and use common sense though.

Reason i asked about smoking is one of the first signs of H/G leak is slight coolant getting into cyl and slight rough run on start up till it burns of. If that were the case it will slowly continue to worsen until you notice sharp fluctuation in temps and too much coolant in overflow.
 

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Discussion Starter #8
Dear NAJ,
Am I correct that, in the engine compartment pic, the FP sensor is connected to the brass fitting directly in front of the crank? If in the fuel line does it give an accurate pressure reading? I thought readings had to be after the regulator and directly from the fuel rail.

Dear Shadow,
Forgot to mention I did check the water and oil for cross contamination and there was none. Also nothing odd with the overflow tank. However, now you have me worried and I'm thinking I should do a cylinder pressure test. I actually have that tool so don't have to wait.

Thanks, DDBob.
 

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I assume you have a two piece installed. If my car has non CB Valve cover, I remove the PR on the rail. This allows you to wiggle out the rail and injectors. My CSX now has a CB valve cover, so I just pop it off. The rail/injectors are easier to remove.
Once the rail is out why don't you test as NAJ suggests above, It is quick and easy.
 

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Discussion Starter #10
Thanks for the tips. I was going to wait to pull everything apart until after the FP test. Hopefully, get the adapter tomorrow.
 

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I have also seen HEPs do this, they may be the strangest to chase down because I've seen them do so many different things from dying and that it (simple) to dying then restart in 5-20 min and go on like that for a year, to running rough once in a while on start up and when you come to a stop ect ect. All with no HEP code.
 

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No, pressure is checked before the FPR, the pumps output is always at max, the FPR allowing fuel to go back to the tank always keeps pressure in the lines at regulated pressure under ALL operating conditions.(Total Fuel Pressure is measured across the injector tip, combo of rail pressure and engine vacuum/pressure)
It would be like checking water pressure at your faucet.
If you placed a gauge inline right before the faucet and the faucet was closed you would read max pressure, (which would be the same as pinching off (deadheading) the return line), when you open the hot or cold water the pressure will drop although at the source max pressure is still being maintained.
Also, the service valve in the fuel rail is before the FPR.
 

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Discussion Starter #13
Thanks for the help.
I got the FP adapter this morning and tested. Discovered someone broke the FP gauge, maybe me, and it's reading 10 lbs with nothing hooked up & 45 lbs running with gas dribbling out, can't trust it. May take a while to get another tester. Mean time, I do have a good Power Module and Logic Module for backup. I'll swap those and see if they make a difference.
Shadow, I rechecked my water & oil for cross-contamination. Nothing in water but under the oil filler cap there was a very small amount of white foam. So small I missed it the first time but it is there. Head has had a super tiny oil leak (looks more like a paint stain) just behind the distributor since I bought the car 10 years ago. I wash the engine every summer and it doesn't show up till next summer. If a blown head gasket I may have to sell the car because my medical issues are making it increasingly difficult to do hard repairs. DDBob
 

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Discussion Starter #14
Thanks again for your help.
PM & LM swap made no difference.
Thinking (hoping) the little bit of foam on the oil cap was just some condensation.
Can't get another FP test kit until Monday or Tuesday.
Oh well, this & quarantine saves gas money but it sure is boring.
Stay safe, DDBob.
 

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Discussion Starter #15
Still waiting on my brother's FP tester. Although aloud to work all tools, including their own, are on lockdown. Waiting sucks! Mean time the plan is to get a Glowshift electric gauge and have a small engine compartment gauge.
NAJ, your engine compartment photo shows 2 brass couplings for the sensor.
1) Any problem with drilling & tapping a hole in the big one to install a little gauge?
2) Space is tight on these cars, where'd you run the wiring through the firewall?
Thanks, DDBob.
 

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Discussion Starter #16
Forgot to mention. The gauge that I have with incorrect and wandering readings. With engine running it does provide readings between 40-45 but when engine is shut off immediately drops to zero. If a leaking injector wouldn't it take longer? Malfunctioning fuel pump? It's a certified Walbro from FWDPerformance with maybe 10,000 miles.
 

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I would not drill and tap brass fittings only because you do not want any fuel leaks.
I ran the wiring under the weatherstrip and through the grommet where the clutch cable runs through the firewall.
Engine Compartment Front-2014.JPG
The easy way to see if the issue is with the pump, injector(s) or FPR is have someone turn the car off and immediately pinch off the inlet line, if pressure now holds the issue is with the pump/pump hanger, If pressure still drops repeat on the return line, if pressure now holds the problem is with the FPR,if pressure still drops repeat and pinch both lines at the same time, if pressure drops you have a leaking injector(s).
 

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Discussion Starter #18
Thanks NAJ. Will hit it today while the sun's shining. The foreseeable problem, pressure drops so fast I won't be able to pinch the line quick enough.
 

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Discussion Starter #19
Well this sucks!
Foreseeable problem proved true. At engine shut off FP drops to zero instantly, impossible to pinch off in time. Even if a single injector was stuck open wouldn't it take 5-10 seconds for FP to hit zero? If so wouldn't instant zero pressure indicate a problem in the return line? No gas on the floor.
Forgot to mention, I checked all around injectors & fuel pressure regulator, removed FPR vacuum hose and everything's bone dry.
If not the return line or other suggestions I'm guessing the next step is to pull the fuel rail & injectors and test them. I've got an injector rebuild kit in case O rings get torn and it includes the little filters.
Some 3 weeks ago I cut 2 fingers to the bone so they're not fully healed. Should feel great getting gas on them.
Thanks again.
Stay home, stay safe.
DDBob.
 

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Pinch the return line off first and then turn the key on, your gauge should go to maximum pressure, if it holds you know the FPR is the issue.
If you had an injector leaking that badly you would see it with an extremely fouled spark plug and/or cylinder misfire and lots of black smoke.

***Be 100% sure the losing pressure immediately issue is not with your Gauge or you really will be chasing a ghost.
 
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