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 suddenly running rough and low power

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convert2diesel
phantom 309
TheRoadmasterKing
jbol
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jbol




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PostSubject: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeSat May 07, 2016 3:36 pm

I want to see if anyone can aim me in the right direction before I do a lot of unnecessary stuff.
Filled up with gas. Next day it has less power and seems to be pulsing - brum, brum, brum.
I am getting codes 22 (TPS) and  44 (02). There does not seem to be any causes they have in common.
I don't have a lot of the handy measuring tools some of you have like fuel pressure and compression but might be ab;e to find some.
Should have mentioned - 5.7 TBI, 93 Roadmaster
thanks in advance
jim
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Fred Kiehl

Fred Kiehl


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeSun May 08, 2016 9:19 am

The fuel pressure is nearly impossible to check. It is possible to get the fuel lines off of a 92 (maybe 91 as well) Fleetwood with an LO3/5 that will fit directly on the 91-93. You can also use the lines from a 93 FW (LO5), but they are a slightly different shape, although they do bolt in. They have a Schrader valve port. The only way to check fuel pressure without changing the lines is to make a T fitting that will go between the nylon hose and the metal one on the passenger's side of the engine, or between the filter and the line. There are no fittings available to purchase that I know of. The Caddy lines are the most elegant and simple way of getting a fitting.

I would check the ground at the thermostat housing first. That is the ground for the O2 sensor, and computer.

Sometimes things fail instantiously. You could try replacing the TPS, and if that does not work, then the O2 sensor. If the TPS is not working correctly, it will affect the fuel mixture, and that will be read by the O2 sensor.

It is probably not the compression, so save yourself some effort.

A notorious item is the hose between the pump and sending unit. This is a 23 year old car. The hose is known to crack vertically, and cause the symptom you are experiencing. That would be the third item I would check. Yes, you do have to pull the tank to get to it. While you are in there, you might as well replace the pump with a new DELCO pump. I replaced the hose, and a month later I ended up replacing the pump. I do not like to pull the tank any more than is necessary, so save yourself a second job.

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TheRoadmasterKing




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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeSun May 08, 2016 9:41 am

Fred Kiehl wrote:
The fuel pressure is nearly impossible to check. It is possible to get the fuel lines off of a 92 (maybe 91 as well) Fleetwood with an LO3/5 that will fit directly on the 91-93. You can also use the lines from a 93 FW (LO5), but they are a slightly different shape, although they do bolt in. They have a Schrader valve port. The only way to check fuel pressure without changing the lines is to make a T fitting that will go between the nylon hose and the metal one on the passenger's side of the engine, or between the filter and the line. There are no fittings available to purchase that I know of. The Caddy lines are the most elegant and simple way of getting a fitting.

I would check the ground at the thermostat housing first. That is the ground for the O2 sensor, and computer.

Sometimes things fail instantiously. You could try replacing the TPS, and if that does not work, then the O2 sensor. If the TPS is not working correctly, it will affect the fuel mixture, and that will be read by the O2 sensor.

It is probably not the compression, so save yourself some effort.

A notorious item is the hose between the pump and sending unit. This is a 23 year old car. The hose is known to crack vertically, and cause the symptom you are experiencing. That would be the third item I would check. Yes, you do have to pull the tank to get to it. While you are in there, you might as well replace the pump with a new DELCO pump. I replaced the hose, and a month later I ended up replacing the pump. I do not like to pull the tank any more than is necessary, so save yourself a second job.

I actually saw a video on Youtube of a Roadmaster idling badly and in the comments the video poster commended that his fuel line cracked and that's what caused the issue. Is your car acting like this?

YouTube video poster wrote:
thanks for the reply. it ended up being the rubber hose that connects the fuel pump to the sending unit. it was 20+ years old and developed a slit in it. replaced it all and everything is fine!
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jbol




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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeSun May 08, 2016 12:20 pm

The idle has a small pulsing - not enough to notice on the tach and quicker than what the video suggests - and no soot.
It is harder to tell when driving but seems worse when going up a hill when there is an obvious loss in power.
thanks
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lakeffect

lakeffect


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeSun May 08, 2016 1:47 pm

You can "somewhat" check the pump without pulling the tank.
You need a spare battery or pull the one from the car and a few wires to do it.

At the rear of the car, underneath , coming off the tank is a harness that unplugs.

Unplug it.

 You'll need to run some  heavy gauge wire from the battery terminals to the tank harness.The black will be grounded to the battery negative side. Of the other two wires one is for the fuel gauge, the other for the pump. Unfortunatly I can't recall which color is which.

The point of it is that you are trying to HEAR what the pump is doing,  If all you hear is simply the pump, It might be OK  

If you hear splashing noise, or for lack of better eloquent words, the sound of your fuel pissing all around in the tank from a crack or hole in it, then it's the hose and you will be dropping the tank to fix it. the worst part of it for me was the three fuel line disconnects coming off the tank  to the chassis lines. Pain  in the butt.
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phantom 309

phantom 309


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeSun May 08, 2016 9:35 pm

well is it just me or,,....

car was running fine,. you put gas in it,.

Next day car is running bad,..

whats the odds its bad fuel,.? try a pint of methyl hydrate in the gas,..
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lakeffect

lakeffect


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeSun May 08, 2016 9:43 pm

Good point. I missed that.
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Fred Kiehl

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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeSun May 08, 2016 10:41 pm

The odds of it being bad gas is 0.000, unless you pumped diesel in it.
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phantom 309

phantom 309


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeSun May 08, 2016 10:54 pm

Fred Kiehl wrote:
The odds of it being bad gas is 0.000, unless you pumped diesel in it.


0.000?

what makes you so sure it not honey oil,..
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Fred Kiehl

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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeMon May 09, 2016 7:21 am

Even a moron would pump gas from a gas station, so it must be motor fuel. Whether it is gas or diesel is not a common error, it has happened. The chances of getting "bad gas" at a random station is virtually nonexistent, or all of the cars that got gas there would not run properly.
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lakeffect

lakeffect


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeMon May 09, 2016 7:25 am

Maybe they all got bad gas but he's the only one that posted on this forum about it.
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Fred Kiehl

Fred Kiehl


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeMon May 09, 2016 7:30 am

What are the chances of that?
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convert2diesel




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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeMon May 09, 2016 9:10 am

Fred:

Bad gas is a reality. Numerous reasons for it from a dealer letting his tanks go low so your pumping all the crap from the bottom of the tank to a bad load from the tank farm. The inline filters at the pump, if they haven't been by-passed, are only about 30 microns, to allow for the high volume flow. That still lets a lot of crap through.

Learned years ago to buy gas only from high volume dealers, especially when on long trips. Have picked up bad fills, both gas and diesel, on numerous occasions.

Bill
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lakeffect

lakeffect


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeMon May 09, 2016 9:53 am

Fred Kiehl wrote:
What are the chances of that?

My point, Fred, is that literally hundreds could have the same problem from the same fuel, same dealer, but by percentage, but what is the likelihood that any of them drive B-body wagons and would end up reporting it here on this forum?

I'd say pretty slim.

Wouldn't surprise me to hear there are more reports on Honda and Toyota forums. Not arguing...Just sayin'....
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Fred Kiehl

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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeMon May 09, 2016 1:16 pm

I have never experienced "bad gas" in 50 years of driving. The chances that he got bad gas is almost zero. The symptoms are not that of "bad gas" anyway. The symptom would be knocking and misfires. His symptom is fluctuating idle, and that would not be a symptom of "bad gas".
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phantom 309

phantom 309


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeMon May 09, 2016 9:27 pm

Fred Kiehl wrote:
I have never experienced "bad gas" in 50 years of driving. The chances that he got bad gas is almost zero. The symptoms are not that of "bad gas" anyway. The symptom would be knocking and misfires. His symptom is fluctuating idle, and that would not be a symptom of "bad gas".

condensation in fuel tanks is very common up here due to large swings in temperatures,.and water in gas exhibits the same symptoms as was described,.
You living in florida have maybe not experienced much water in fuel,.

what are the chances of that?

You may have been driving for 50 years,. but i,m damn sure i,ve driven about 5 times further in my 42 years,.
and in a lot more varied environments,..

Nuff said,. back to the fred kiehl channel.
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Fred Kiehl

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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeTue May 10, 2016 7:37 am

I lived in PA until 1995, and I never had a problem there either. The symptoms still do not match "bad gas".
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convert2diesel




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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeTue May 10, 2016 9:00 am

Fred Kiehl wrote:
I lived in PA until 1995, and I never had a problem there either. The symptoms still do not match "bad gas".

You sir have lived a charmed life.

Bill
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silverfox103
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silverfox103


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeTue May 10, 2016 9:41 am

In the winter in northern New England, every convenience store, hardware, grocery store and auto parts store, all sell "Dry Gas" which is used to remove water / moisture from gas. Seems to work.

Tom
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Fred Kiehl

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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeTue May 10, 2016 10:44 am

It is not winter, and you do not know if he lives in the north.
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Sprocket

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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeTue May 10, 2016 11:08 am

<<
Usually, it's been water in the gas and a bottle of dry gas helps. Maybe 3 or 4 times and never in the same car twice. Reading the original post that was my first thought. If it continues after that tank of gas, then I'd start looking for other stuff.
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silverfox103
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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeTue May 10, 2016 12:28 pm

Fred Kiehl wrote:
It is not winter, and you do not know if he lives in the north.

It's not winter where you live, but I have another 2 months of winter!
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lakeffect

lakeffect


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeTue May 10, 2016 1:20 pm

So rather than worry about when Winter starts or ends, Are we going to help the guy solve his problem?
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phantom 309

phantom 309


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeTue May 10, 2016 8:34 pm

nah,. we'll just let fred pass gas,..
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Fred Kiehl

Fred Kiehl


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeTue May 10, 2016 8:57 pm

I gave the OP valid information on troubleshooting his issues in my first post. The interim chase down the rabbit hole is passing bad gas.
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jbol




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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeWed May 11, 2016 12:27 am

I don't really think it is bad gas - live in Texas and have filled up twice since problem started. School is out after this week and I will start trying some of the suggestions.
If anything the problem is a bit worse.
If it is idling and I put my hand behind the exhaust it is like puff, puff. puff like some cylinders are missing. Driving uphill it is chugging.
thinks for all of the interest shown so far
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phantom 309

phantom 309


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PostSubject: Re: suddenly running rough and low power   suddenly running rough and low power Icon_minitimeWed May 11, 2016 7:40 am

Well,. so much for the bad gas theory,.

What were the chances of that,..
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