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 Rough idle and hesitation at low speeds

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CapriceCarl



Posts : 9
Join date : 2015-02-24

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PostSubject: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeTue Feb 24, 2015 3:07 pm

Hey guys! I was looking for a FAQ or walk through for an issue like this, but wasn't able to find one. Does anyone know where I could find one? Or if another forum has one?

Basically I've got a 92 Custom Cruiser with the 305 that starts up and idles perfectly fine. 230k miles on him. Its only when I put it into gear and only sometimes does it cause a loss of RPM, hesitates, and stumbles ONLY when driving slowly in a neighborhood or in a parking lot.

If I add a little fuel the car feels like it wants to cut off unless I give it a lot. If I just tap the throttle, as soon as I let off the car will lose RPM, jiggle and sorta stumble trying to find the correct idle. But like I said, only when crusing at very slow speeds. On the highway he seems fine. No codes, or *12 using the paper clip method.

I've ordered a new EGR and ICV and will probably put in new plugs and wires while I'm at it. I was just curious if this sounded directly familiar to anyone, or if there was a thread with a sorta flow chart on what I should be checking.

I'll continue to search through the forums. Thanks for any help you guys can give!
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CapriceCarl



Posts : 9
Join date : 2015-02-24

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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeTue Feb 24, 2015 5:16 pm

http****://vid1280.photobucket.com/albums/a497/Only1Balto/20150224_134600_zps0sn1ys70.mp4


Video of whats going on.
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CapriceCarl



Posts : 9
Join date : 2015-02-24

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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeTue Feb 24, 2015 5:36 pm

Just did cap and rotors, no change.
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71novaguy



Posts : 233
Join date : 2014-01-14

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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeTue Feb 24, 2015 6:42 pm

Vacuum leak
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HoosierDaddy



Posts : 101
Join date : 2014-12-28

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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeTue Feb 24, 2015 7:03 pm

Test or replace the throttle position sensor.
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CapriceCarl



Posts : 9
Join date : 2015-02-24

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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeTue Feb 24, 2015 7:24 pm

Thanks guys. I checked for vac leaks with the carb cleaner.

I'll look at testing the TPS.
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Fred Kiehl

Fred Kiehl

Posts : 5287
Join date : 2009-11-13
Age : 70
Location : Largo, FL 33774

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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeTue Feb 24, 2015 9:26 pm

My experience with a 92 OCC with a 305 that would act strangely, but not throw a code, was the small rubber hose between the fuel pump and output hose on the sender unit. I swapped out almost everything I could think of, until the only thing left was a fuel problem.

If you want to be able to check your fuel pressure, you can get a set of fuel lines from a 91-92 Fleetwood with an LO3/5 or a 93 Fleetwood. They both have Schrader valve ports on them.

If I were you, I would at least pull the fuel tank, and check the hose. It is a PITA job, but it is a lot cheaper than swapping out all of the sensors. BTW if it is not throwing a code, the part that causes the code is probably good. Fuel issues do not throw a code.
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Bobloblaw

Bobloblaw

Posts : 121
Join date : 2014-08-17
Location : Arizona

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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeTue Feb 24, 2015 9:42 pm

Just out of curiosity, how old is your fuel filter?

I know, I know....dont kill me.
Had a non-b body vehicle do this. Turned out to be the fuel filter.
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CapriceCarl



Posts : 9
Join date : 2015-02-24

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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeTue Feb 24, 2015 11:11 pm

Car has 220k, probably still on the stock fuel filter. I'll do those next. Thanks guys.

No codes.
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CapriceCarl



Posts : 9
Join date : 2015-02-24

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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeTue Feb 24, 2015 11:29 pm

Fred Kiehl wrote:
My experience with a 92 OCC with a 305 that would act strangely, but not throw a code, was the small rubber hose between the fuel pump and output hose on the sender unit. I swapped out almost everything I could think of, until the only thing left was a fuel problem.

If you want to be able to check your fuel pressure, you can get a set of fuel lines from a 91-92 Fleetwood with an LO3/5 or a 93 Fleetwood. They both have Schrader valve ports on them.

If I were you, I would at least pull the fuel tank, and check the hose. It is a PITA job, but it is a lot cheaper than swapping out all of the sensors. BTW if it is not throwing a code, the part that causes the code is probably good. Fuel issues do not throw a code.


I saw your post about the same subject on another thread. Have you seen the video I posted? Was your TBI acting the same way? I'm just looking for a sure step before I walk in that direction.
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Guest
Guest



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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeWed Feb 25, 2015 2:00 am

Fuel pump isn't as hard as it's made out to be on these cars.

That's my educated Internet guess, too.
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CapriceCarl



Posts : 9
Join date : 2015-02-24

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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeWed Feb 25, 2015 5:13 pm

I installed a new ICV and EGR. Started it up and let it run for 3-4 minutes. Then took it for a small test drive above 40 mph. No signs of low RPM's! I think I even got a little more pep out of him. I'll be looking at taking care of the fuel filter and pump next. Thanks guys!
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cbshea13

cbshea13

Posts : 101
Join date : 2013-09-06
Age : 45
Location : York, PA

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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitimeWed Apr 22, 2015 9:29 pm

I'll go down my checklist of things that I did, and what eventually fixed it.

About 6 months ago, I had a distributor put in (not something I could do in the time I had on the side of the road in front of my house). About two weeks after that, I had a low rpm when in gear, with the occasional stall. I chased the problem, replaced a few sensors, and a week would go by and the problem would come back. Replaced EGR, IAC, TPS (again, did one at fall wagon fest), even the Air Charge Temp Sensor. I'd get a week or so of the problem going away...only for it to come back.

So, I did what my father suggested some 6 months ago when the problem started. Checked the timing, only to find it out of whack. Since last Friday, I've had 0 issues with that problem, and I've noticed my MPG's are back to normal!

My original problem was an occasional massive drop in RPM when I put it in gear, with a very rare stall when under very light acceleration. (I found my fix reading through a similar problem on a truck forum).

On a side note, I've sent back my fuel pump and sock (I had to order through work, lol) as this fixed the problem.
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PostSubject: Re: Rough idle and hesitation at low speeds   Rough idle and hesitation at low speeds Icon_minitime

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