Name : Nemo Joined : 2021-09-20Post Count : 25 Merit : 0
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Wed Oct 27, 2021 2:45 pm
And... it's not the alternator. The car won't stay running. What am I missing? Also, fie on the jackal who put this bolt on this way.
Jack the R Master
Joined : 2007-01-16Post Count : 8072 Merit : 105
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Wed Oct 27, 2021 3:08 pm
Is the problem that it won't start, or that it won't stay running?
Is it possible these are two separate problems?
For a while I had intermittent non-starts that turned out to be the starter relay. It eventually died completely, leaving me stranded.
Later on the car would randomly die on me. At first I thought it was the fuel pump, but replacing the fuel pump didn't fix the problem. After that I replaced the crankshaft position sensor and the camshaft position sensor, and she's been good ever since.
BTW did not mean to suggest earlier that your car was on its last legs. You may not have taken it that way, but now that I reread it, that's what it sounds like.
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StellaRae95 Amateur
Name : Nemo Joined : 2021-09-20Post Count : 25 Merit : 0
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Wed Oct 27, 2021 3:26 pm
Jack the R wrote:
Is the problem that it won't start, or that it won't stay running?
Is it possible these are two separate problems?
For a while I had intermittent non-starts that turned out to be the starter relay. It eventually died completely, leaving me stranded.
Later on the car would randomly die on me. At first I thought it was the fuel pump, but replacing the fuel pump didn't fix the problem. After that I replaced the crankshaft position sensor and the camshaft position sensor, and she's been good ever since.
BTW did not mean to suggest earlier that your car was on its last legs. You may not have taken it that way, but now that I reread it, that's what it sounds like.
I've had both issues, but right now it won't stay running. Crankshaft & camshaft position sensors are a possibility I hadn't thought of, but I'll check since I also thought it was the fuel pump at first.
And all good man, I know how "last legs" read but I also know that's not what you meant. Starting to feel true though, I've only gotten to drive it 1/4 my time of ownership.
Jack the R Master
Joined : 2007-01-16Post Count : 8072 Merit : 105
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Wed Oct 27, 2021 5:21 pm
I don't know how you would check those sensors. If yours are original you can expect to replace them. The good news is, buying the most expensive option is only $100 for both. The bad news is, you've got to take a bunch of stuff off to get to the camshaft position sensor, so you might as well replace a few things while you've got them off. The crankshaft sensor is "only" buried under the harmonic balancer, which is a bastard to pull/replace if you don't have the tools or know what you're doing. The harmonic balancer bolt is also a "one-use-only" item, so you have to replace that. NAPA has already reassigned the part number to a different bolt, and the other parts stores may be the same. I had to get mine from the GM dealer.
The 8th gen Riv works well when you have it all together. It can be a pain to bring back an old car, but at least it's a good one.
StellaRae95 Amateur
Name : Nemo Joined : 2021-09-20Post Count : 25 Merit : 0
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Thu Oct 28, 2021 11:00 am
Jack the R wrote:
...which is a bastard to pull/replace if you don't have the tools or know what you're doing.
I clearly have no idea what I'm doing, but that's the point isn't it? A failing crankshaft sensor seems to be the most accurate diagnosis yet (no start, start but dies, excessive fuel consumption leading to a smell, and misfire), so that's the one I'm gonna go with today. I swear, it's always a damn sensor with these cars! I had a 92 PA for 5 years (213000 miles at purchase), and the ONE TIME it wouldn't start, it was the throttle position sensor. The only reason I haven't completely given up is because of that 3800. 5 years of nonstop dependability will do that. Stella owes my old PA a debt of gratitude, because any other car would have been sold/junked by now.
Jack the R Master
Joined : 2007-01-16Post Count : 8072 Merit : 105
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Thu Oct 28, 2021 11:34 am
StellaRae95 wrote:
Jack the R wrote:
...which is a bastard to pull/replace if you don't have the tools or know what you're doing.
I clearly have no idea what I'm doing, but that's the point isn't it?
That's how I roll. With the help of the forum, I've always been able to get the car back together and working again. I usually manage to take a few months with anything I do though.
StellaRae95 wrote:
A failing crankshaft sensor seems to be the most accurate diagnosis yet (no start, start but dies, excessive fuel consumption leading to a smell, and misfire), so that's the one I'm gonna go with today.
I don't remember having a smell or misfire.
Here's my adventure in starter relay testing - Link
You can read about my crankshaft position sensor change adventure here - Link
I had to buy a $400 DeWalt impact wrench to put the new harmonic balancer bolt in, and a impact sockets (not the same as regular sockets). I've used it quite a bit on other jobs since, but it was a hit I didn't care to take at the time.
StellaRae95 Amateur
Name : Nemo Joined : 2021-09-20Post Count : 25 Merit : 0
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Thu Oct 28, 2021 12:07 pm
Jack the R wrote:
StellaRae95 wrote:
Jack the R wrote:
...which is a bastard to pull/replace if you don't have the tools or know what you're doing.
I clearly have no idea what I'm doing, but that's the point isn't it?
That's how I roll. With the help of the forum, I've always been able to get the car back together and working again. I usually manage to take a few months with anything I do though.
Good to know I'm not the only one! I'm a little ashamed to admit, but it took me 2 weeks to replace the water pump on my 85 Fleetwood. In my defense, it was literally the first car repair I had ever done.
Jack the R wrote:
StellaRae95 wrote:
A failing crankshaft sensor seems to be the most accurate diagnosis yet (no start, start but dies, excessive fuel consumption leading to a smell, and misfire), so that's the one I'm gonna go with today.
I don't remember having a smell or misfire.
Lucky. I haven't seen either since the coil was replaced. I wonder if the crankshaft sensor ruined that coil....
Thanks for linking the write-up, I was looking for it! The impact wrench is gonna be a hard no, that's literally my rent money. Looks like it's gonna be another adventure for "Tiny but Mighty."
StellaRae95 Amateur
Name : Nemo Joined : 2021-09-20Post Count : 25 Merit : 0
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Thu Oct 28, 2021 1:32 pm
Jack the R wrote:
You can read about my crankshaft position sensor change adventure here - Link
That's outside of my abilities with the tools on hand and the location I'm in. I'm gonna have to call a mobile mechanic. Fuuuu......
Jack the R Master
Joined : 2007-01-16Post Count : 8072 Merit : 105
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Thu Oct 28, 2021 3:46 pm
StellaRae95 wrote:
Good to know I'm not the only one! I'm a little ashamed to admit, but it took me 2 weeks to replace the water pump on my 85 Fleetwood. In my defense, it was literally the first car repair I had ever done.
You did better than I did with my first water pump. Somehow I came up with the wrong torque settings for the bolts and they were waaay too low. Hello coolant! That was not on the Riviera, in case anyone is wondering.
The placement of the crankshaft position sensor is unfortunate. You might find a cheaper brand impact, but do your research before blowing your cash. I feel your pain on this one. I only found out about the extra expenses when my car was apart. There's also a special tool for holding the flex plate in place so the engine doesn't turn over when installing the bolt. IIRC it's around $80 used, and it's just a dinky little thing. Your mobile mechanic won't have it. Some people use vice grips instead. I was worried about damaging the flex plate and bought the tool.
The mechanic may, or may not, have a torque angle gauge. The one I got was cheap and did the job find.
You might be able to skip the impact if you can arrange a long enough breaker bar, and set the car up where you can use it. I think you would pretty much need the car on a lift though. I haven't worked with a lift myself. It might take so much torque to crank the bolt down that it would move the car, which would be crazy dangerous on a lift.
LARRY70GS Aficionado
Name : Larry Age : 68 Location : Oakland Gardens, NY Joined : 2007-01-23Post Count : 2193 Merit : 150
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Thu Oct 28, 2021 3:53 pm
There are a number of ways to torque a balancer bolt down. You need to stop the crank from turning. My favorite way is to pick a cylinder, doesn't matter which one. Then remove the spark plug and feed a length of nylon rope into the cylinder. Then turn the crank until it stops. Then torque your bolt. It effectively locks the crank and is easy on the piston. It works like a piston stop.
Another is to unbolt the pulley from the balancer. Then get a piece of angle iron of suitable length, and using the pulley bolts, bolt it to the balancer. When you turn the crank bolt, the angle iron hits the ground and stops the crank from turning.
_________________ 98 Riviera SC3800 All stock except gutted air box. 1970 Buick GS455 Stage1, TSP built 470BBB, 602HP/589TQ Best MPH, 116.06 MPH, Best ET, 11.54 https://www.youtube.com/watch?v=UHCda-t_Jls https://www.youtube.com/watch?v=sfT2tEO4XcU
StellaRae95 Amateur
Name : Nemo Joined : 2021-09-20Post Count : 25 Merit : 0
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Thu Oct 28, 2021 7:35 pm
LARRY70GS wrote:
There are a number of ways to torque a balancer bolt down. You need to stop the crank from turning. My favorite way is to pick a cylinder, doesn't matter which one. Then remove the spark plug and feed a length of nylon rope into the cylinder. Then turn the crank until it stops. Then torque your bolt. It effectively locks the crank and is easy on the piston. It works like a piston stop.
This idea scared me at first, but the more I think about it, the more I like this idea!
Hey Jack, do you remember the final torque value you finished with? My eyes started crossing from all the reading I did today so I might've missed it, but the 111lb/ft+76° is not ideal.
Jack the R Master
Joined : 2007-01-16Post Count : 8072 Merit : 105
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Thu Oct 28, 2021 8:06 pm
I don't like torque-to-yield either, but there's no way of guessing what the final torque rating is. It might even be different each time, depending on how much grit is in the bolt hole. Or so it was explained to me. I cranked mine over 76 deg with the impact and couldn't tell you what that amounts to, but it must be pretty high. The crazy strong impact had to work for a while to do it. I think I got the bolt to 111+20 degrees manually first with a 200 ft/lb torque wrench. I put all 200 ft/lbs into the bolt and I couldn't budge it a bit further. If I'd known it was going to take so much force to do +76 degrees I would have set up the car different, but the way I had it, I couldn't get a longer bar on the car and it wouldn't have had hardly any range of motion.
StellaRae95 Amateur
Name : Nemo Joined : 2021-09-20Post Count : 25 Merit : 0
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Mon Dec 06, 2021 1:29 pm
So, I ran out of cash and had to put the car on ice for a bit, but now I'm back. Got my hands on a FSM too, but this thing is THICC and tough to understand for a beginner.
I hired a mechanic, who changed the rubber fitting on the hose leading from the boost sensor and I finally got to drive my car home, but it refused to start the next day. So I checked all the other fittings I could see and replaced what I could. She starts, still dies, but it's an improvement over no start at all. I want to go back to the basics (air, fuel, spark) because maybe it's a simple issue that I overlooked. Spark: When running, all 6 cylinders feel like they're firing. Fuel: There is definitely pressure at the rail, enough for me to start the engine and idle for 20-30 seconds before RPMs steadily decline until death. Could be a problem, but it doesn't seem likely to me because of how quickly it'll start up again. Air: I suspect this as the most likely culprit because of the vacuum diagnosis. I realize I've been hearing a sucking sound when the car was running and was just oblivious.
What chapter in the book should I look at? I'm pretty lost.
StellaRae95 Amateur
Name : Nemo Joined : 2021-09-20Post Count : 25 Merit : 0
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Mon Dec 06, 2021 2:18 pm
Huh. Pretty sure my TPS connector isn't supposed to look like that....
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8687 Merit : 181
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Mon Dec 06, 2021 3:03 pm
StellaRae95 wrote:
So, I ran out of cash and had to put the car on ice for a bit, but now I'm back. Got my hands on a FSM too, but this thing is THICC and tough to understand for a beginner.
I hired a mechanic, who changed the rubber fitting on the hose leading from the boost sensor and I finally got to drive my car home, but it refused to start the next day. So I checked all the other fittings I could see and replaced what I could. She starts, still dies, but it's an improvement over no start at all. I want to go back to the basics (air, fuel, spark) because maybe it's a simple issue that I overlooked. Spark: When running, all 6 cylinders feel like they're firing. Fuel: There is definitely pressure at the rail, enough for me to start the engine and idle for 20-30 seconds before RPMs steadily decline until death. Could be a problem, but it doesn't seem likely to me because of how quickly it'll start up again. Air: I suspect this as the most likely culprit because of the vacuum diagnosis. I realize I've been hearing a sucking sound when the car was running and was just oblivious.
What chapter in the book should I look at? I'm pretty lost.
When the car is running, what happens to fuel pressure readings at the rail? HINT: with the electric fuel pump (FP), when you turn the key it will allow the fuel system to build pressure. If, however, the FP is not making adequate flow/pressure after car's starting, then the car will burn fuel faster that the FP is pumping. So it will start and die. The figures should be in your fine manual but I think you're looking for 48# or better, say 50#, key-on-engine-off and 45# or better running (or whatever it says in your service manual).
If your flow is inadequate, maybe it's the fuel filter but gas is so clean in general nowadays that isn't likely. Before you mess with the filter, though, [i]check/replace the fuel pressure regulator. A bum FPR will act for all the world like a dying fuel pump. Depressurize your rail then get a set of snap ring pliers and take your FPR off the rail. If you discover it's holding gas inside itself, replace it.
Thinking out loud what you might want to also do is pull the hatch in the back and just look at the top of the fuel pump while you're at it, see if there is anything obviously wrong. You will need (well, you will *want*) a GM or a Universal fuel pump spanner to remove/replace it.
StellaRae95 Amateur
Name : Nemo Joined : 2021-09-20Post Count : 25 Merit : 0
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Fri Dec 10, 2021 12:51 pm
albertj wrote:
When the car is running, what happens to fuel pressure readings at the rail? HINT: with the electric fuel pump (FP), when you turn the key it will allow the fuel system to build pressure. If, however, the FP is not making adequate flow/pressure after car's starting, then the car will burn fuel faster that the FP is pumping. So it will start and die. The figures should be in your fine manual but I think you're looking for 48# or better, say 50#, key-on-engine-off and 45# or better running (or whatever it says in your service manual).
If your flow is inadequate, maybe it's the fuel filter but gas is so clean in general nowadays that isn't likely. Before you mess with the filter, though, [i]check/replace the fuel pressure regulator. A bum FPR will act for all the world like a dying fuel pump. Depressurize your rail then get a set of snap ring pliers and take your FPR off the rail. If you discover it's holding gas inside itself, replace it.
Thinking out loud what you might want to also do is pull the hatch in the back and just look at the top of the fuel pump while you're at it, see if there is anything obviously wrong. You will need (well, you will *want*) a GM or a Universal fuel pump spanner to remove/replace it.
Back to the fuel system, yay. I'll start checking things this afternoon when it warms up a little. It shouldn't be the FPR though, I replaced that two months ago. No fuel in the line when I checked the other day either.
I had a random thought. I've had poor braking since day one (I can stop, but the pedal doesn't inspire confidence at all). Do you think a vacuum loss of sufficient size from the booster could create bad brakes and keep killing my engine?
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8687 Merit : 181
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Sat Dec 11, 2021 7:45 pm
StellaRae95 wrote:
I had a random thought. I've had poor braking since day one (I can stop, but the pedal doesn't inspire confidence at all). Do you think a vacuum loss of sufficient size from the booster could create bad brakes and keep killing my engine?
I don't know.
But, if you have a vac leak at the booster, effort to stop the car increases (a lot).
Just fix it.
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LARRY70GS Aficionado
Name : Larry Age : 68 Location : Oakland Gardens, NY Joined : 2007-01-23Post Count : 2193 Merit : 150
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Sun Dec 12, 2021 3:10 pm
A vacuum leak will often trigger a CEL for a lean condition. You can also easily check engine vacuum with a vacuum gauge. My engine fully warm makes a full 20" of vacuum at idle. Anything less than that, there is a leak. And yes, that will significantly increase braking effort.
_________________ 98 Riviera SC3800 All stock except gutted air box. 1970 Buick GS455 Stage1, TSP built 470BBB, 602HP/589TQ Best MPH, 116.06 MPH, Best ET, 11.54 https://www.youtube.com/watch?v=UHCda-t_Jls https://www.youtube.com/watch?v=sfT2tEO4XcU
StellaRae95 Amateur
Name : Nemo Joined : 2021-09-20Post Count : 25 Merit : 0
Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..) Sun Mar 06, 2022 6:50 pm
Hey folks! Tax time means Riv time! I'm working with a mechanic who thinks the problem is electrical, either the PCM or one of the fuse boxes underneath the rear seat. Apparently, the problem is strong enough to drain my battery down to 3V. (It wasn't vacuum lines, apparently, and he also says fuel pressure at the rail is good.) Any suggestions welcomed.
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Subject: Re: I guess this is my various query thread? (formerly "Fuel pump won't stop..)
I guess this is my various query thread? (formerly "Fuel pump won't stop..)