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  • Fuel Pressure Testing Adapter!

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A place to discuss different tools we use to keep our cars running.

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 #357483  by MunchMan
 April 16th, 2016, 9:56 am
For those of you looking for an easier way to test the fuel pressure, Actron makes this 90 degree right angle adapter for $9.50 with shipping YMMV. My tester could not bend enough with the ignition coil in the way, so I thought there had to be an easier way.

https://actron.com/content/right-angle- ... er-adapter
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 #365692  by goodwrenchldj
 March 11th, 2017, 9:48 pm
Mike, I have a similar 90 degree adapter. I tried using it on my 300M but was unsuccessful. It does not clear the valve cover. Unfortunately, I damaged he threads on the fuel rail pressure tester access port. I removed the upper intake manifold for clearance and repaired the threads with a 7/16-20 die. Even with the manifold off the adapter will not fit. It still contacts the valve cover. Your thoughts please
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 #365705  by FIREM
 March 12th, 2017, 7:14 am
Pull the coil for #4 plug, install gauge, reinstall coil, test fuel pressure.
 #365719  by goodwrenchldj
 March 12th, 2017, 2:28 pm
The #4 coil and the upper intake manifold have both been removed. I still can not install the 90 degree adapter. It hits the valve cover. If you go to http://www.speedwaymotors.com/Auto-Mete ... 13902.html you will see the 45 degree adapter that I have ordered. It should be here on Wednesday. I hope this works.
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 #365727  by FIREM
 March 12th, 2017, 8:34 pm
Be sure the elbow has the "pin" to depress the "schrader" valve in the fuel rail. Something sounds out of the ordinary here. I have always been able to connect to the fuel rail, usually with the coil in place.
 #365746  by goodwrenchldj
 March 13th, 2017, 11:06 am
Thanks for your responses. I agree that something is amiss. The adapter I am using looks like the one you recommended and has the pin for the Schrader valve in the fuel rail fitting. The problem is that I can not attach either my fuel pressure gauge or the adapter to that fitting. Both approach the fitting at an angle due to contact with the valve cover. Due to this I damaged the threads on the fitting. I removed the upper intake manifold for better access so that I could repair the threads with a 7/16-20 die. I still can not get my 90 degree adapter on the fuel rail fitting.

Please view my post regarding why I am interested in monitoring fuel pressure in the maintenance section of the forum. Your thoughts will be appreciated.
 #378532  by wilsons_automotive
 April 2nd, 2019, 1:27 pm
I have 4 dodge Intrepid, 2 chrysler LHS one Concord and one 300m. I have the same problem... 90deg threaded fuel pressure tester adapter hits the left valve cover on all of my cars. I have not found a fix.. any ideas would be very helpful
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 #378536  by Mottman
 April 2nd, 2019, 6:45 pm
DARKFIRE ( 99 300M ) Also has this issue.
The valve-cover is in the way !
Maybe grind a small clearance notch in the valve-cover ?
( yeah, I don't like that idea either )
A different ( newer style 3.5L fuel-rail ?
Maybe we should look for another type of adapter that connects
between the fuel-rail and the fuel-line ?
 #378557  by wilsons_automotive
 April 4th, 2019, 6:11 am
I don't think the cover is thick enough to grind a notch that would allow enough clearance without going through the cover completely and wrecking the cover. From what I know Mitsubishi designed the top end of the engine.. probably explains why it has the problem in the first place.
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 #378558  by beespecial
 April 4th, 2019, 9:35 am
I checked my fuel pressure last summer with a gauge borrowed from AutoZone. Didn't have to remove anything. It screwed right on.
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 #378561  by Sneke_Eyez
 April 4th, 2019, 2:00 pm
wilsons_automotive wrote: April 4th, 2019, 6:11 am I don't think the cover is thick enough to grind a notch that would allow enough clearance without going through the cover completely and wrecking the cover. From what I know Mitsubishi designed the top end of the engine.. probably explains why it has the problem in the first place.
I have never heard that before.
The 3.5L was a Chrysler designed (1g) and then slightly Chrysler-re-engineered (2g) motor. As a matter of fact, we heard from one of the Chrysler engineers who worked on it at Carlisle last year.
What is your source?
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 #378563  by Mottman
 April 4th, 2019, 6:02 pm
I have heard alot of people seem to think these engines
were made or designed by Mitsubishi.
ALLPAR has an interview with one of the head engineers
that designed these engines ( Marc Rozman )
It is actually an all MOPAR, " in house ' design.
 #378570  by wilsons_automotive
 April 6th, 2019, 11:58 am
With the hydraulic valve lash adjuster being located in the rocker arm I believed it was straight outta the Mitsubishi camp. I'm glad to know that its Mopar. Anyhow.. I modified the back of the brass knurled fitting that threads onto the test port on the fuel rail. I used a bench grinder to carefully remove enough material (at a 45° angle) where it just clears the left side valve cover. Its still tight but it works without damaging the test port threads.