Unbelievable, I switched to Mobil1 0w40 from 10w30 & my car never got off the lift.
After living in denial about fuel pump failures, knowing better all the while, ignoring the infrequent E-Minor musical note from the trunk area, my fuel pump gave up the ghost.
Erratic fuel pressure out of the filter when I did get it to start, (20 something to low 30's) 1.1 ohms resistance, (spec .5) 11 volts at the fuel pump control unit (acceptable, I think, since by battery is questionable & my battery cables need replacing)
Terminals at the control unit look good, I think I'm going to replace the pump & see what happens. Do I really need a FPCU also?
Opinions?
TIA
Only I could make my car not run after an oil change (fuel pump failure)
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Q451990
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You will probably need the FPCU as well.
Pop the cover on the controller and see if any of the components look fried. There are four (two on each side) that are screwed to the aluminum heat sink case. They look like transistors, but I think they're something else, a rectifier bridge and a couple of other things if memory serves me right. On my failed unit (and one other I saw) these components were toast but the connectors were fine. I looked up these parts and they can be be purchased for about $10 online, but I found one in a salvage yard for $50 before I went that route.
FPCUs in the junk yard are getting pretty rare - I think I looked at every Q in the greater Columbia area before I finally found one that was still there. Makes you wonder how many that are bought are plugged in to bad pumps and meet a rapid death.
BTW... you have to remove the package tray to get the FPCU out - there are two 10mm bolts on the right side near the front of the deck - they're both typically burried under the sound deadening material, so you'll need to peel it back.
Heath
Pop the cover on the controller and see if any of the components look fried. There are four (two on each side) that are screwed to the aluminum heat sink case. They look like transistors, but I think they're something else, a rectifier bridge and a couple of other things if memory serves me right. On my failed unit (and one other I saw) these components were toast but the connectors were fine. I looked up these parts and they can be be purchased for about $10 online, but I found one in a salvage yard for $50 before I went that route.
FPCUs in the junk yard are getting pretty rare - I think I looked at every Q in the greater Columbia area before I finally found one that was still there. Makes you wonder how many that are bought are plugged in to bad pumps and meet a rapid death.
BTW... you have to remove the package tray to get the FPCU out - there are two 10mm bolts on the right side near the front of the deck - they're both typically burried under the sound deadening material, so you'll need to peel it back.
Heath
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HeavyDuty
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95 Nissan 240SX S14
96 Nissan D21
06 Nissan 350Z Z33
Yup, spent about an hour "discovering the power of the button." 
I'll have the pump delivered this morning, but was the FPCU recently replaced on your old 91?
I noticed it taking an extra second or two while starting the last couple weeks, also, I did use a judicious amount of Techron in two successive tanks recently, apparently that didn't help the pump much.
I guess if I have to remove the rear shelf anyway. I might as well look inside the FPCU.
Hello Repoman???
HD, currently driving a 72 Buick GS455 525hp/650tq. $54 in fuel costs since Saturday.
PalmerWMD wrote:Contact repoman.He currently holds my old 91 Q and he can sell you the FPCU off of it.
I have dibs on the fuel pump though, as my pump is also making noise.
Fred..
I'll have the pump delivered this morning, but was the FPCU recently replaced on your old 91?
I noticed it taking an extra second or two while starting the last couple weeks, also, I did use a judicious amount of Techron in two successive tanks recently, apparently that didn't help the pump much.
I guess if I have to remove the rear shelf anyway. I might as well look inside the FPCU.
Hello Repoman???
HD, currently driving a 72 Buick GS455 525hp/650tq. $54 in fuel costs since Saturday.
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Q451990
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HeavyDuty wrote:I noticed it taking an extra second or two while starting the last couple weeks, also, I did use a judicious amount of Techron in two successive tanks recently, apparently that didn't help the pump much.
That sounds familiar from the week or two before mine failed.
It's amazing how many of us know there's a problem from the board (myself included) but then wait too long. After you replace the pump once you'll see how easy it is, and it won't happen again
I wouldn't be concerned about the mileage or age on a FPCU, since they don't seem to fail unless they're abused by a bad pump. I'd think a physical look under the cover to make sure nothing looks burnt would work tell you most of what you need to know.
Heath
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HeavyDuty
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95 Nissan 240SX S14
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06 Nissan 350Z Z33
New pump installed, started up fine, went for a test drive, up to temp & nailed it, too fast for a drop to 1st gear so I waited patiently for the power to turn on......hit 4000 rpm & subsequently a limp mode w/check engine light.
WTF?
Pulled the code, 11, CAS. Restarted the car & barely touched the CAS harness, it shut off. Noticed the CAS is directly above the oil filter. A-HA! :rolleyes I must have kissed the connector with the back of my hand as I was breaking the filter loose from above, just enough to loosen a female spade or two on the plug.
Adjusted the tension on the spades, now with a nice tight fit, all is well with the world again.
The pump was going bad & it feels a lot better, the car was just trying to tell me to change it now.
AZ, the A Body is a 72 GS 455, stock block, .030 over forged pistons, nodular iron crank, stock rods, but TA performance Stage I aluminum heads, TA shaft mounted rollers, Edelbrock Performer intake (to retain the ram air) Demon carb, TA front cover, with revised oil pump & water passages, MSD dist/ignition, Hooker Super Comps with TorqueTech 3" mandrel bent ceramic coated exhaust (through the N-25 (?) rear bumper), TH400 with GearVendors under/overdrive & PI converter, Global West tubular (*negative*
camber) suspension, 100% suspension resto, rear disc conversion, Hotchkis RLCA's, Koni's, lift bars, TA rear cover, Weld Rodlite 18x8's, Michelin Pilot sports, full under hood wiring restoration, PS, AC, PW, PDL. Currently white/green stripe, soon to be yellow/black (the way it came).
I can post pics tomorrow if you'd like, I had a 71 SS454 Monte Carlo when I was in high school, A bodies will always have a soft spot in my heart, too. It's so nice to be a part of a forum where there are those that see beyond whatever marque they happen to be driving at the time and appreciate others for what they are.
PS, you're dating yourself (and me) with the World of Wheels show.
WTF?
Pulled the code, 11, CAS. Restarted the car & barely touched the CAS harness, it shut off. Noticed the CAS is directly above the oil filter. A-HA! :rolleyes I must have kissed the connector with the back of my hand as I was breaking the filter loose from above, just enough to loosen a female spade or two on the plug.
Adjusted the tension on the spades, now with a nice tight fit, all is well with the world again.
The pump was going bad & it feels a lot better, the car was just trying to tell me to change it now.
AZ, the A Body is a 72 GS 455, stock block, .030 over forged pistons, nodular iron crank, stock rods, but TA performance Stage I aluminum heads, TA shaft mounted rollers, Edelbrock Performer intake (to retain the ram air) Demon carb, TA front cover, with revised oil pump & water passages, MSD dist/ignition, Hooker Super Comps with TorqueTech 3" mandrel bent ceramic coated exhaust (through the N-25 (?) rear bumper), TH400 with GearVendors under/overdrive & PI converter, Global West tubular (*negative*
camber) suspension, 100% suspension resto, rear disc conversion, Hotchkis RLCA's, Koni's, lift bars, TA rear cover, Weld Rodlite 18x8's, Michelin Pilot sports, full under hood wiring restoration, PS, AC, PW, PDL. Currently white/green stripe, soon to be yellow/black (the way it came).I can post pics tomorrow if you'd like, I had a 71 SS454 Monte Carlo when I was in high school, A bodies will always have a soft spot in my heart, too. It's so nice to be a part of a forum where there are those that see beyond whatever marque they happen to be driving at the time and appreciate others for what they are.
PS, you're dating yourself (and me) with the World of Wheels show.
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Q451990
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- Contact:
Sounds like the CAS may have been part of your problem to begin with too. The good news is that you replaced the fuel pump without toasting the control unit! The hard start (mine was more of like a stumble after starting in the normal time, just for a few seconds) sure sounds like your pump was about a week away from frying the FPCU. Probably a good time to check the MAF connectors and sub CAS sensors connections too.
Are you changing the oil filter from the top?? :thumbd That's a bad idea for the MAF connector... I don't think it was designed for r/r every 90 days.
Glad to hear that everything is squared away!
Heath
Are you changing the oil filter from the top?? :thumbd That's a bad idea for the MAF connector... I don't think it was designed for r/r every 90 days.
Glad to hear that everything is squared away!
Heath
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HeavyDuty
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95 Nissan 240SX S14
96 Nissan D21
06 Nissan 350Z Z33
The CAS didn't act up at all before the oil change, I think I whacked it during the operation, or just dumb luck. I already did the same fix on the MAF plug, that is what was wrong with the car when I bought it.Q451990 wrote:Sounds like the CAS may have been part of your problem to begin with too. The good news is that you replaced the fuel pump without toasting the control unit! The hard start (mine was more of like a stumble after starting in the normal time, just for a few seconds) sure sounds like your pump was about a week away from frying the FPCU. Probably a good time to check the MAF connectors and sub CAS sensors connections too.
I did it from below the first change, but I have one of those dreaded pop chargersQ451990 wrote:Are you changing the oil filter from the top?? :thumbd That's a bad idea for the MAF connector... I don't think it was designed for r/r every 90 days.
so I thought I'd give it a try from the top.