Rough idle + pinging

[bubba22349]

Dose'nt sound like pingging to me more of exhaust tone with a missfire

 

[MPGmustang]

try this for your next recording...
put recorder in a big carboard box (think basketball or bigger), this will get rid of wind noise, put box under car under the engine/tranny bellhousing
with foot on brake and car in drive, rev the engine and hold to a higher speed than idle (simulate maintaining speed) roughly less than 2000rpm, then relax and rev up too slowly multipule times to 2500rpm in 2-5 sec times (simulate getting up to speed/stop and go traffic). total length could be around 30-40 sec's

you can try the same in rev if you would like so we can hear the difference, either way the engine should be under load

warning, be nice to your tranny, over reving can hurt it, it's 40+ years old with alot of mileage on it. if you think it's too high of a rev then it's too high and don't rev that high. just don't brake anything. honestly we only need to hear it when it's talking

your clips are just too short for me "hear" anything definitivly... and I think all I hear is exhaust tone/open header...

keep up the good work, you're doing great with the information!

 

[thesameguy]

Yeah, I had hoped to extend my recording session, but my little fuel problem put an end to my documentary.

I pulled the fuel pump off last night - there is some wear on the lever, but no obvious signs of damage. I have an electric pump coming tomorrow, and I'll pick up a block off plate tonight. Then, hopefully get back to troubleshooting this weekend.

What are the chances the pressure relief valve in the fuel pump is/was sticky? Perhaps holding too much or not enough pressure at various times? A fuel pressure gauge would have answered that question, but we're beyond that now. I am just wondering if perhaps the relief valve failure on Wednesday is the final failure mode of something that's not been right for a while.

I didn't realize at first, but the previous owner of the car had installed Fram fuel filters on both the inlet and outlet of the fuel pump. Not sure if carbed cars are like fuel injected cars, but every car I've ever worked on required the filter to be installed in a specific way. The way this guy had set things up, the filter on the inlet side of the pump was in the wrong direction. Crazy guy had FOUR filters on this thing - one on the pump inlet, one inside the pump, one on the pump outlet, and one before the carb. WTF? Also, the filter on the pump itself had been sealed with teflon tape - I'm pretty sure that's a no-no, as teflon tape and fuel don't tend to get along very well... There wasn't much left on any of the threads. I can only imagine that stuff dissolved and went somewhere - probably into one of the four fuel filters. :nono:

 

[bubba22349]

A stock fuel pump with it's filter is good system, with all the filters sounds to me like tank must have a bunch of dirt and or rust. With a lot of trash in there it will plug filter than when it sits it will open up again. I would pull tank you can replace it or take to be cleaned at chemstrip or a good radiator shop after cleaning I use the aircraft slushing comp. to seal it.

 

[thesameguy]

A stock fuel pump with it's filter is good system, with all the filters sounds to me like tank must have a bunch of dirt and or rust. With a lot of trash in there it will plug filter than when it sits it will open up again. I would pull tank you can replace it or take to be cleaned at chemstrip or a good radiator shop after cleaning I use the aircraft slushing comp. to seal it.

Actually, last night when I was removing the fuel pump, I also checked out the situation in back to see where I was going to stick the pump & how I was going to plumb it. I drained a couple gallons of gas out of the tank and it looked perfect. Not a spec of rust or dirt came out. The fuel also looked great spilling out of the line at the front of the car that feeds the pump, so I don't think there is any rust in the underbody fuel line, either. The underside of the car is less rusty than my '95 Alfa - the tank looks very new... of course that's no indicator of what it looks like inside. I think the previous owner either didn't know what he was doing or just got filter happy. Much of the car seems very kludged together - but I'm working on that. By way of example, when I bought the car the owner was sure it had some massive electrical problem because sometimes it wouldn't turn over - after removing a poorly installed alarm system and replacing a bunch of badly-insulated wiring, I found the problem was the safety switch on the gear selector. Hey, now the car starts every time! (Doesn't run right still, but it does start. )

 

[69.5Mav]

with all the filters sounds to me like tank must have a bunch of dirt and or rust

That is what it sounds like to me as well. Iwould at least look at the condition of the first fuel filter in the system. You've got a 60 year old tank there. No telling how much junk is in it or when it may break loose. In my case when they started putting ethanol in the gas, it disolved the varnish that was binding up all the trah, my 72 mav started puking up all sorts of trash. When I removed the tank it had 1/2" chunks that covered the bottom of the tank. I took the tank to a radiator shop and they cleaned it and sealed it for me. The car would run just long enough for me to get a mile or so and then starve out. Come back lator and start up fine, run then conk out again. Lots of trash in the fuel filter.

Don't think this is your main problem but it one more thing that can bite you just when you think you have solved the last problem.

 

[redxm]

Been following this thread for a while. Couple I things I thought of..
As it seems to happen or not happen at all by turning the ignition on/off.. - Is the ignition switch intermittant high resistance?
I had a car once that had a horrible rattle at various times that sounded a lot like pinging. It turned out to be loose convertor bolts. May be worth popping the cover off and checking.

 

[thesameguy]

I haven't noticed anything odd with the ignition switch - converter bolts? Not familiar with that... ?

 

[Frankenstang]

I had a car once that had a horrible rattle at various times that sounded a lot like pinging. It turned out to be loose convertor bolts. May be worth popping the cover off and checking.

That's a very good idea...torque 'converter' bolts...you can check for loose/broken ones by pulling the inspection cover as redxm suggests....I'm definitely leaning towards a driveline issue or some other odd noise maker...doesn't do it in reverse and your timing measures do not indicate over advance...video doesn't seem to support it either...noise at low speed/low rpm not WOT where pinging is most noticeable. Good luck!
EDIT:..oops, meant to write, "not under load or near WOT where"....

 

[thesameguy]

You know, I could completely see torque converter bolt heads contacting the bellhousing making this noise, echoing in the bellhousing and under the car. It's still odd that the noise doesn't happen in reverse and doesn't happen consistently, though my lower flex plate cover is AWOL, so it shouldn't be much of a job to check.

 

[JackFish]

I have had a deep knock in my engine I've been trying to diagnose.
Finally used a mechanics stethoscope to pinpoint where it was coming from.
In my case, I'm now fairly certain it's the oil pump.
Looking forward to pulling the engine next week. :x

If your "pinging" occurs at idle then I doubt that it's related to the actual pinging that is caused by pre-ignition.

Heck, look for some loose exhaust manifold bolts.

 

[69.5Mav]

I would check the flex plate for cracks and weather the torque converter is bolted up to the flex plate correctly

I had a car once that had a horrible rattle at various times that sounded a lot like pinging. It turned out to be loose convertor bolts. May be worth popping the cover off and checking.

That's a very good idea...torque 'converter' bolts...you can check for loose/broken ones by pulling the inspection cover as redxm suggests

Finally used a mechanics stethoscope to pinpoint where it was coming from.

I was just going to suggest using a stethoscope. Here's a link to an inexpesive one.

http://www.harborfreight.com/mechanics- ... 41966.html

They also have digital ones for $40. I'm not sure what advantage you gain by spending 10 times the money but each to their own.

One more place to check for noise is the Ujoints especialy the front one. When they break they can make a clang that could be mistaken for a ping if it's soft enough. easy to check too.

 

[thesameguy]

Unfortunately The Noise (which I'll stop calling pinging - hope springs eternal ) only occurs in Drive, under load. It'd be kinda hard to have my head under the hood while going down the road. I cannot remember if I can reproduce the noise with my foot on the brake or not - as soon as I get the fuel pump situation resolved I'll check that out. But, the fact it only seems to make the noise while the car is in motion is what is making this thing so bloody hard to troubleshoot. I have a very good stethoscope, I just have yet to figure out how to apply it to this situation!

I had a similar situation on my XR4Ti, a high pitched squeal/whine sound that only happened over 8psi of boost. I spent WEEKS trying to track down what I was sure was a pinhole leak in the intake plumbing, and found quite by accident it was a hairline crack on the underside of the elbow off the turbo.

Edit: I don't think it could be a u-joint (or a wheel bearing) since it's not related to road speed but engine load. I could see it being engine or transmission related since it's an automatic and "road speed" doesn't always exactly equal "engine speed," but even that's a stretch.

 

[69.5Mav]

I don't think it could be a u-joint

Ujoints are real easy to check and it would eliminate one more thing from the list. To make this noise the Ujoint would have to be seriously worn out. Just turning the drive shaft back and forth while watching for play in the Ujoint should be enough to reveal a joint this bad.

 

[69.5Mav]

It'd be kinda hard to have my head under the hood while going down the road.

I had a thought on how you might be able to do that.

If you can find a smoke check station that will let you put your car on their load rollers.

Or if you can find a Dyno shop and instead of a HP pull ad get the car under load and search for the noise.

 

[chad]

Break area?
It would help to locate the "region" of the thing...
Under hood, near pass. floor boards, etc...

 

[thesameguy]

It'd be kinda hard to have my head under the hood while going down the road.

I had a thought on how you might be able to do that.

If you can find a smoke check station that will let you put your car on their load rollers.

Or if you can find a Dyno shop and instead of a HP pull ad get the car under load and search for the noise.

The thought has occurred! I don't think California emissions shops would let me do it since they're pretty tightly regulated, but it's worth a try. There is a Volvo shop around the corner that has a dynojet they charge $75/hr for, so that's an option as well. It wouldn't be cheap, but possibly cheaper than me continuing to throw parts at this thing.

I've working on the electric fuel pump install now. The block-off plate is installed, I removed the 305 fuel filters the previous owner installed, got a 5/16" fuel pressure gauge T fitting & a mechanical gauge, the Carter P4070 tentatively mounted to the floorpan by the tank, and wiring/fuse/relay installed to run it. Unfortunately I failed to notice the P4070 comes with 3/8" hose barbs and the Falcon is all 5/16". Nobody around here carries 1/4" NPT->5/16" fuel hose barb, and I'd prefer not to use standard hose barbs if I don't have to. It started raining here, so the project is on hold - if it clears up I'll just go with standard 5/16" hose barbs for now, but I ordered a pair of correct fittings from Jegs a little earlier.

I have high hopes the old fuel pump was the culprit and the electric will cure my issues, but really low expectations that it will. We'll see - at least I'll be able to rule out fuel delivery as the issue.

 

[thesameguy]

Break area?
It would help to locate the "region" of the thing...
Under hood, near pass. floor boards, etc...

I can't tell where it's coming from - it's definitely in front of me and not behind me, but it's hard to narrow it down more than that. It does not seem to be louder with the hood up vs. down, but that ultimately doesn't indicate much - it's not like a '62 Falcon has a tightly insulated body & engine compartment.

 

[thesameguy]

Got the fuel pump essentially done today - folks weren't lying, the sucker is LOUD. I have some NVH tuning to do, it seems.

That said, I now have a single filter between the tank and the pump, and 5/16" metal tube & hose all the way to the carb. The fuel going through the filter is spotless, so I am reasonably certain my tank is just fine - there certainly isn't anything coming out of it! I have a solid 6-7psi at the carb, or so says el cheapo Mr. Gasket pressure gauge. My previous issue of massive flooding at shutdown is gone, so I think the old pump's relief valve was toast. I also notice the fuel entering the carb is extremely well atomized, which was not the case before. The car starts & idles better than ever. In fact, superbly. I am pulling 16-17 inches at the manifold - I t'd off the line that goes to the transmission's vacuum modulator and hooked up a boost gauge (too bad I have no boost ). Adjusting idle speed & mixture has an instant affect on the vacuum, so I think all that is working properly.

It still makes The Noise. It just can't be pinging, it can't be. It's something else. Here is what I know:

1. In reverse, I can rocket down the driveway in total silence
2. In reserve, I can mash the brakes and accelerator, overpower the brakes (one wheel burnout!), and still not get The Noise
3. In neutral, I can hammer the throttle and rev it til I'm nervous and not get The Noise
4. In drive, I rocket down the driveway making The Noise the whole way
5. In drive, I can mash the brakes and accelerator and get The Noise
6. Disconnecting the vacuum advance on the distributor has no affect on The Noise.

Both my girl and I did some 1/16 mile sprints down the driveway with our heads hanging out and the hood up. She says it's coming from "forwards and down" - I can't effing tell.

Since it it doesn't matter if the car is actually moving or not I think I can rule out things like wheel bearings, rear ends, driveshafts. In any case, the u-joints feel totally tight. Since it does not make The Noise in reverse, apparently regardless of load, I think I can rule out the engine, and probably anything on the car itself that just rattles.

So, transmission? What in you-know-where inside the transmission could make a noise like this?

Thanks guys, I feel like great progress is being made!

 

[thesameguy]

More: Because I have no concept of personal safety, I jacked the rear end up, started it up, put it in drive, and tried to make The Noise. I was totally unsuccessful at that for a couple reasons, however it came to light that you can *barely* hear The Noise with it just idling in Drive and your head under the car. It does seem to be coming from the transmission, but maybe the torque converter? Hard to tell, but now I should be able to break out the stethoscope and get closer to it.