Jump to content

1972 Buick Riviera 455 oil pressure light comes on after engine is started (idling range RPMs), combined with a suspected fuel pump failure - related?


Recommended Posts

NTX5467 ... yes (and thank you for the link, I drilled into that last night ... it will seemingly take some digging to see if there is anything there I can make use of) ... I'm pretty sure my Cruise Master system is factory installed ... I have the turn signal stalk with the 'Apply' button on the end (no switches, just the end push-button with script on the end of the stalk: '◄ CRUISE' pointing towards the button) and, EmTee, I'm pretty sure I have a(n) (functioning?  maybe not under the current circumstances) indicator light on the dash ... in between the L turn indicator light and the dreaded 'OIL' light ... can't quite make the un-illuminated script out ... it will not light up with ignition ON and the 'Apply' button pushed ...

 

 ... at any rate, my focus is to find factory parts illustrations / servicing illustrations of the actual appearance, types, locations and connections of the vacuum tubing involved at and around the Power Unit (LR of top of engine) and Transducer (L inner fender-mounted) in order to figure out where the Subject (of my thread post here) disconnected vacuum hose is supposed to connect.

 

TeamBuick has an excellent resource to the '1972 BUICK SERVICE MANUAL - SECTION A - CRUISE MASTER', (pages) 65-2 through 65-17 here.  (I hope I am not violating their rights by posting snapshots of illustrations (below) from their free online resource, or, for that matter, violating any policies of this site - if so, I will redact the snapshots immediately)  However, after rotating pages 65-9 thru 15 90°CW in order to properly study the illustrations provided, I find that the illustrations (i.e. page 65-12

image.png.940aa849cd11c28649560f15113c37cc.png

- Note: some illustrations are for 'All Series', some for select Series, i.e. my Riv being a Series '4Y') stop just short of showing that which I seek ... the actual Power Unit / Transducer vacuum source connection (at the carburetor / intake manifold? yes?), as intended by the factory.

 

The illustration on page 65-10 is not for my Series, and, the illustration at page 65-11 (All Series)

image.png.86bb173581b0805e98e06d24b8e5f96f.png

shows what appears to be a vacuum source hose nipple at the rear, center, carb base, but no vacuum hoses are illustrated, per se (see photos of my existing installation posted by me earlier in this thread, here & here).

 

I'll have to trace the vacuum hose that is currently connected to my carb base ... my money is on the vacuum brake connector back at the draw bar hitch location but I will have to check it to be sure.  Maybe you cannot have the two types of devices (C.M. and trailer brakes) competing for vacuum, otherwise why wouldn't the RV shop installing the vacuum trailer brake connection have just tee'd the hoses at the carb base? (to a substitute 'T' fitting for the existing straight hose nipple fitting)

 

FFF

Link to comment
Share on other sites

4 hours ago, Frankenstien said:

Maybe you cannot have the two types of devices (C.M. and trailer brakes) competing for vacuum, otherwise why wouldn't the RV shop installing the vacuum trailer brake connection have just tee'd the hoses at the carb base?

Yes, maybe the trailer brake and cruise control are incompatible.  The cruise has to automatically disengage when the brake is applied.  I don't know anything about your trailer brake setup, but maybe there was no way for the trailer brake to automatically disengage the cruise control, so it was disabled?

Link to comment
Share on other sites

The aftermarket systems from back then looked nothing like the OEM factory units.  ARA sold aftermarket cruise kits which looked like re-purposed Chrysler systems, servo and all.  Not sure about the Dana/Perfect Circle aftermarket systems.  PLUS, the turn signal stalks were different, too.  Typically, the ARA and D/PC systems also had MEMORY, which the GM units did not have until the early 1980s.

 

FWIW,

NTX5467

Link to comment
Share on other sites

NTX5467 ... don't hold my feet to the fire on the C.M. origin / source, but I am nearly 100% certain that what I have is factory installed ... and I also did establish just now that there is 12VDC power to the transducer (so, apparently, the [RV?] shop that did the vacuum trailer brake install and presumably left the Power Unit's vacuum source hose flapping in the breeze saw fit to not bother disabling C.M. electrically) ... with the ignition on, there is power to the green wire / 'LIGHT' connector, with ignition on and the 'Apply' button pushed (on the end of the steering column stalk), there is power to the black wire / 'ENGAGE' connector and at the brown wire / 'HOLD' connector, there is no power with ignition on, nor with ignition on and 'Apply' button pushed, nor with ignition on and brake pedal pushed (I did not try pushing both at the same time) ...

I still have to lift the car and trace the vacuum trailer brake hose from the draw bar hitch connector forward to whatever vacuum source was tapped ...

FFF

Link to comment
Share on other sites

Unless you plan to tow with the car, I suggest that you remove the trailer brake system and put everything back as it left Flint.  Aesthetically, it would also make sense to remove the trailer hitch.  Someone had a hitch on my '67 at one time and I have one hole in the center of the bumper, down low, that I filled with a chrome bumper bolt.  My Riviera is also equipped with factory air shocks, so I presume the original owner installed the hitch.  Does yours have air shocks?

 

Edited by EmTee
typo (see edit history)
Link to comment
Share on other sites

EmTee ... I don't plan on towing because the only things I have to tow are boats and this car looks like it has to go too far into the water (R brake lines, drums, ect. could be immersed) to launch or recover my trailered boats (1 lake boat into fresh water lakes, 2 others that are salt chuck boats going into the Pacific Ocean) ... I also don't believe it has air shocks (there's a new wrinkle for me ... I didn't even know you could order Rivs back then with air shocks!  What was the idea?  A trunk full of gold but the car could still be levelled out?), however, I will look today when I have the car lifted ... good thought!

 

I guess the one chrome bolt low on your bumper would only register with the most savvy of observers ...

 

FFF

Link to comment
Share on other sites

Delco Air Shocks came out in about '67 or so.  Factory option in many cases, but could also be installed later on.  Tended to end the use of Air Lift branded air bags installed in the rear suspension.  End result . . . the cat sat level with the weight on the trailer hitch.  Generally, if the hitch on the car is a simple Class I, many times owners did not bother with air shocks.  Especially if all they hauled was a small trailer with their golf cart on it.

 

Never have heard of a vac-controlled trailer brake unit.  Most I've ever seen were elcto-mechanical in actuation, with electrical adjustment of the "force" of the trailer brakes.

 

FWIW,

NTX5467

Link to comment
Share on other sites

 ... so ... circling back to the fuel pump replacement task, I've got the carb fuel inlet pipe disconnected, the inlet filter housing removed and found no debris in the filter cavity (I'm surprised there was no metal or other (nylon? ... seems to be available for this purpose these days) gasket behind the large, cylindrical inlet / filter 1"-20 housing ... I have yet to find a proper exploded view of it [for: Rochester QuadraJet 7042240] ... the only replacement filter available to me locally is a FRAM CG3389) ... anyways, during two 10-second cranking tests (with 30 seconds in between for starter motor cool down) the fuel pump did not pump a drop of fuel, as expected ... even though the fuel tank is 11/16~ full ... as NTX5467 suggested earlier on, I'll remove, carefully identify (as near as I can make out, those f. p. hoses are 3/8" & 1/4" I.D., respectively ... apparently 9/32" no longer exists [unless you go with 7mm] and 5/16" is too big for the smaller f. p. hose nipple as tested on the Delphi replacement fuel pump) and replace the two short sections of flexible rubber fuel hose connecting to and at the pump ... my problem may be as simple as a supply hose cracked badly enough from age that it leaks air in enough that the poor pump is doing nothing but trying to pump air ...

 

 ... another concern is the age of the gasoline in the tank ... I have a bottle of 'NOS MAX RACING OCTANE BOOSTER' ("NOS Increases octane effect up to 6 full octane numbers or 60 points (1 octane number = 10 points). " ... and ... try as I might, I cannot find that NOS product on Permatex's website) that I can add to the tank, however, that's 17.25625~ U.S. gallons to treat (if fuel tank capacity is 25.1 USgal), NOS advises a 12 fl. oz. bottle will treat 12-16 U.S. gallons of fuel, so, at least I'm not over-dosing the fuel in the tank ...

 

 ... thoughts?

 

Thanks, FFF

Link to comment
Share on other sites

Do NOT run that old gas or you'll likely be dealing with bent pushrods and stuck valves.  Drop the fuel tank and rinse it out.  Remove the sender and inspect.  At the VERY LEAST, siphon out as much old gas as possible and refill with new gas (preferably non-ethanol).

  • Thanks 1
Link to comment
Share on other sites

Posted (edited)

EmTee ... I am a little surprised at how strongly you (and, frankly, others I've encountered online) feel about old gasoline (really old gasoline has a varnishy smell that helps to differentiate it from 'fresh' gas ... my car's tank was last filled on 23JUL2011 with Chevron [Canada] Supreme Plus [94 [octane (M+R/2)] gasoline ["94 OCTANE IS ETHANOL-FREE ... "] with 76,161.4 miles on the odo ... so, since its' got 76,187.5 on the odo now, that means it's gone only 26.1 miles in the 11~ year interim ... and I've somehow lost the better part of 5/16~ of a tank to ? ... evaporation? ...  can't be thievery ... the car's in a locked garage [that remains well above ambient external temperature and humidity conditions ... in winter]) ... anyways, I've been down this path a few times before and I've never encountered any of the problems you list EmTee ... dropping the fuel tank?  With all due respect, that's just not happening ... siphoning out all the old gas? ... granted, not as big of a deal as dropping the tank, however, that's not happening either ... I'll dose the gas in the tank with my NOS octane booster mentioned in an earlier post and later fill the tank with the same gasoline as mentioned earlier ... if I bend pushrods and / or valves get stuck early on during use of the car, you can say I told you so ... besides, I still don't have resolution of my potentially low engine oil pressure issue anyways, so, am more inclined to accept some further risk to the engine, however, I do not expect any issues such as you describe.  FFF

Edited by Frankenstien
clarifications (see edit history)
Link to comment
Share on other sites

Old gas????  Remember that the FIRST factions of the gasoline to evaporate are the lighter ones (which increase octane over what the basic blend has in it).  So, you might have started with 93 pump octane fuel, but now have less than 85 pump octane.

 

FORGET that fuel additive as it probably has a LARGE amount of alcohol in it.  Most octane boosters only raise Research Octane a few points, not nearly what some seem to indicate on their bottles, by observation.  That additional alcohol in the octane booster will also lean out the fuel mixture, which is why similar brands ALSO recommend an increase in main jet size so the resultant fuel does not make the air/fuel mixture too lean, so larger main jets off-set that situation.  Which also means a carb disassembly to do the jet changes!

 

Even in a closed fuel system, there will be enough temperature changes to result in condensate in the tank, which combined with any ethanol or alcohol in the fuel, will result in "phase separationi", on the bottom of the tank . . . where the fuel pickup resides.  That gunk will then be transported into the carburetor and flake it out, too.  You can probably get enough of that stuff out via the forward fuel line (supply line to the pump) being disconnected and the rear of the car elevated a bit?  Then, fresh fuel could well dilute the remaining gunk enough that it should not hurt anything.  BUT the completely BEST way to get all of that stuff out is to remove the tank and rinse it out, period.

 

NOW, there are some fuel additives (usually specific to the gasoline-powered electric generator industry . . . not GENERAC but municipal-sized automatic-start generators) which allegedly will re-generate older gasoline in to useable gasoline.  You can find it via Google or similar, as I did a few yars ago.

 

Your car and YOUR feet.

 

NTX5467

Link to comment
Share on other sites

EmTee & NTX5467 ... thanks for the additional thoughts / info ... the NOS octane booster I intend to use label's featured info says it's "Blended with Nitro-Methane" and the FIRST AID TREATMENT portion says "Contains petroleum distillates." ... that is the extent of the contents info on the bottle's label ... below is an excerpt from the MSDS sheet for the product ('PER01-092 12012 OCTANE BOOSTER RACING ANG.pdf'):

image.png.6fa171c093dfda98a557c0e2e31a2867.png

I don't see any mention of alcohol there, per se ...

 

Presumably, also adding methyl hydrate (to mitigate any water condensate that may have accumulated) is akin to adding methyl alcohol / methanol, and is, perhaps, to be avoided? ... based on your observations, NTX5467?

 

FFF

Link to comment
Share on other sites

On 8/10/2022 at 2:41 PM, Frankenstien said:

(to mitigate any water condensate that may have accumulated)

I remember how much water would pour out of the third members on the rear end pile when we took them apart. Makes me wonder how many out of storage cars are lubed with whipped oil and water.

Link to comment
Share on other sites

I ran into a similar situation a few years back.  A mounting cap screw for oil pump had loosened and backed out far enough for the counterweight on the crankshaft to knock the screw out.  the results were a dead engine, the distributor would not rotate.  The oil pump housing was trash.  If your problem is like this, then the pump would leak pressure and oil before any revs would be detected by the pressure switch.  I hope that in your case this is not true.  but "stitch in time saves nine".

Dan

  • Thanks 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...