Vehicle Carb issue… or?

I picked up a ice beater recently with some issues.. it was cheap… and Sherry needs something to tow me off the lake with.

Its a 87 AMC eagle .. strait 6, 4.2 liter(basicly the same as most jeep 4.0) and its carborated.

To make a long story short, the guy had a *cheap mechanic*… It ran like dirt, the timing was obviously off, the idle screw was cranked in so it wouldnt stall(yeah, a backfire is better?).. so I backed off the idle back to normal, an got it as close to in time as possible with a broken timing light(doesnt work). It idles decent and it doesnt miss…

but I didnt lose one problem… no power under load. The car wont kick down when I step on it in driving conditions, and it wont run to higher rpms when under load. It seems to be starving for gas.

The kick down linkage is connected at the throttle.. havent traced it down to the tranny but it has a serious lack of power so I havent messed around with that(least of my concerns right now).

Am I dealing with a bad carb(cant be adjusted other than idle), or am I looking at a probability of a bad valve somewhere? We dont have a lot of money to sink into a new carb if its not a high percentage chance it will fix it.

I know there are other possibilities.. fuel filters(replaing tomorrow), bad gas, etc. I just dont want to get stuck speding unneccisary cash we really dont have. Anyone around the minneapolis with a timing light?

you may also want to make sure your catalytaic convertor is NOT pluged either

sounds like it a timing issue yet

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you may also want to make sure your catalytaic convertor is NOT pluged either

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This is a really good suggestion, got a free car once that ran like crap, had a bad cat, ran great afterwards.

could possibly be a vacuum leak some where.

Sounds really familiar to me. Almost exactly what was happening with my Blazer last year. I would step on the gas and it would either have no power or sputter out on me. Spent alot of unnecessary cash before I found out it was the fuel pump. Just because youre getting gas doesnt mean its working properly under a load. You can normally buy a new pump (not the whole mount) for around 30-50$. I’d never replaced one b4 and had no problem… Hope that helps

Check for fuel pressure! It is pretty common to not have any power when the car gets hot and you have a bad fuel pump.

And check your timing with a light that works. I would focus on these two things.

Good luck Dave!!!

If it runs good and sounds good you should check for it getting full throttle. A good many old ones have been messed with and things changed when it’s as simple as that.

P.S. the fact it’s not kicking down is a good indication of that.

What carb does it have. Rochester or Carter, I assume. I may be able to find you one very cheap. If it is a 4 barrel the secondaries may not be opening or getting enough fuel when they open.

Maybe an accelerator pump?

I am certain its not a fuel pump issue… I can hold the pedal to the floor all day long and it will still run the same(at a lack of power). Usually when a fuel pump is weak on a carborated system, the bowl will eventually empty and the vehicle will stall/starve, and the pumps usualy fail before long(manual pump) I am leaning away from a fuel filter because they often have very similar symptoms as the fuel pump.. the bowl just cant fill fast enough… but I am going to replace the filters anyway because they are cheap and there is a slight chance.

This is a 2 barrel carb, not a 4. I wouldnt be the least surprised to learn the low speed(idle) jet is functioning, and the high speed jet is plugged.. to me, that is what its acting like, but its also the most expensive fix which we dont mind making.. AS LONG AS IT NEEDS IT.

Rebuilding this carb is not an option, I dont have the workspace to do it and I dont want to sit out in the winter messing with 100 gaskets, seals, and jets.. its cheaper to buy a reman carb if you figure in time, frustration, and suffering(its winter).

What sucks is this vehicle was made in the worst of the emmision years and there are no shortage of vaccumm lines, odd ball fittings, and we have some of those handy modern day things like oxygen sensors, etc that are capable of causing problems like this also. This carb as 2 electrical connections going to it that arent choke related… so its a carb with a brain to make it worse.

I might have to do a McGyver and bypass the cat for something to do(just to test).. I never thought about it, but that thing has exhaust issues and the cat had an air tube going to it from the engine that broke sometime in the past.. rather than replace what needed to be, they just welded off the air intake to the cat. I have no idea if that would affect it or not.

Like I said, this guy had a *cheap mechanic*, so rather than fixing somebody elses problem, I am just as likely to be fixing a problem caused by somebody else’s mistake.

I am not an idiot when it comes to wrenching… but I just have *one of those feelings* that its something else causing the issues at hand… like a plugged cat, bad O2 sensor, etc.

If the conveter is plugged you should smell the rotten egg smell.

put your hand by the exaust outlet. If there isn’t hardly anything coming out the cat. converter is plugged

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I am certain its not a fuel pump issue… I can hold the pedal to the floor all day long and it will still run the same(at a lack of power). Usually when a fuel pump is weak on a carborated system, the bowl will eventually empty and the vehicle will stall/starve, and the pumps usualy fail before long(manual pump) I am leaning away from a fuel filter because they often have very similar symptoms as the fuel pump.. the bowl just cant fill fast enough… but I am going to replace the filters anyway because they are cheap and there is a slight chance.

This is a 2 barrel carb, not a 4. I wouldnt be the least surprised to learn the low speed(idle) jet is functioning, and the high speed jet is plugged.. to me, that is what its acting like, but its also the most expensive fix which we dont mind making.. AS LONG AS IT NEEDS IT.

Rebuilding this carb is not an option, I dont have the workspace to do it and I dont want to sit out in the winter messing with 100 gaskets, seals, and jets.. its cheaper to buy a reman carb if you figure in time, frustration, and suffering(its winter).

What sucks is this vehicle was made in the worst of the emmision years and there are no shortage of vaccumm lines, odd ball fittings, and we have some of those handy modern day things like oxygen sensors, etc that are capable of causing problems like this also. This carb as 2 electrical connections going to it that arent choke related… so its a carb with a brain to make it worse.

I might have to do a McGyver and bypass the cat for something to do(just to test).. I never thought about it, but that thing has exhaust issues and the cat had an air tube going to it from the engine that broke sometime in the past.. rather than replace what needed to be, they just welded off the air intake to the cat. I have no idea if that would affect it or not.

Like I said, this guy had a *cheap mechanic*, so rather than fixing somebody elses problem, I am just as likely to be fixing a problem caused by somebody else’s mistake.

I am not an idiot when it comes to wrenching… but I just have *one of those feelings* that its something else causing the issues at hand… like a plugged cat, bad O2 sensor, etc.

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So you had the pump tested?

No, I have no way to test the fuel pressure. There is no valve on it to hook up to like on a fuel injected vehicle. (usually one on fuel rail or just before).

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If the conveter is plugged you should smell the rotten egg smell.

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Not always true. The fuel can sometimes cause this. In the Milwaukee area there is some fuel mixture that is more enviromentally friendly. This stuff also causes the odor you described.

Also cats can be plugged and not give a unpleasant odor.

Just get rid of the cat and use the test tube.

Strait pipes on an eagle.. hmm .. what a way to make an already sexy car more attractive!

The only thing that bothers me about bypassing the cat for the long run is previously owning a truck when the emission test were here in Minnesota(no longer exist).. The previous owner removed the cat when they replaced the engine.. the hydrocarbons were incredibly high without a cat… or seriously life threatening if exhaust were to get into the car.

Considering Sherry’s transmission is going to die soon, this will likely be her daily commuter for a while.. along with 2 kids. I dont think it would be the smartest decision I ever made.

Well, its not the timing, fuel pump, fuel filter, or cat issue

At this point in time I’m going to drive most of the gas out of the car and put some fresh gas in to be sure its not bad gas.. then stick a carb on it.

When you add the gas, put in some Seafoam and that might help clear up anything.

Will do.. I am going to throw some heet (alcohol) in there too.. if it is really bad gas, that will help get the moisture out.

I still have one of those feelings its something stupid. This reminds me of when I picked up a truck, had to replace the gas tank immediately.. went to the station and filled up for a 150 mile trip… it was bad gas, could barely gett 55 mph with a tail wind. Great way to break in a new gas tank

This car isnt that bad.. but I sure with it had some of the power its capable of so I can have a bit of confidence in it.

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Will do.. I am going to throw some heet (alcohol) in there too.. if it is really bad gas, that will help get the moisture out.

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The Seafoam will take care of the moisture too. Don’t put any isopropyl in it (Heet and other additives) that stuff is hard on fuel related parts.

not to mention there should already be 10% alcohol in the gas anyways (ethanol).

Good luck on this Dave!

It could be honestly a number of things.
1) Fuel
2) Timing
3) Vacuum lines
4) valves???

Look at your sparkplugs and make sure they are carmel color. Also, check your oil and make sure you are not flooding and getting gas in the oil.

Theres no gas in the oil, the plugs were replaced recently and there is no blow-by on them. The timing is right on, I checked it with a light yesterday. I dont hear any air sucking from a vaccuum line and I have checked over them fairly well. The ones I have inspected are ok, including the vaccumm advance line.

I guess my next suspect is the oxygen sensor.. its not going to hurt to replace it anyhow. I am not replacing anything until I drive most of this gas out and get fresh gas in it. I would feel really stupid if this was due to bad gas.

The previous owner had his *cheap mechanic* working on it quite often because he has problems with the car stalling coming up to stop signs. The mechanic(back yard) cranked the idle screw all the way and tried to adjust the timing(was probably right on before). I corrected that, and quickly solved the stalling issue… they dont like to idle cold when the choke doesnt work at all!

If worst comes to worst, and I want this car to run right.. there are jeep kits out there that would allow me to put my 350 chevy motor in there! That would take care of the lack of power issue!

If you pull your exhaust apart in front of cat. converter and go for a short drive, it will be noisy but you will know soon if anything is pluged in the exhaust system.

Did that yesterday.. the exhaust is not plugged.. yes, it was noisy.

One thing, if t is a lean condition causing the problem be very careful about running the engine hard. Running lean can detonate the engine quickly.

I drove the car around today for a bit.. it gets around.. until I got home. It will no longer idle. Just one of those days.

Somebody somewhere suggested it could be the carb mounting gasket.. and it could be, that or the intake manifold gasket. There are just so many things it could be, its frustrating.

Tomorrow is another day.. I am pretty much committed to fixing this thing now. I plan on replacing them gaskets tomorrow, along with the oxygen sensor. The previous mechanic accidently unplugged the choke… so with any luck that will function now and it will be one less thing to fix.

Its very strange how the vehicle went from idling perfectly, to not idling at all. When you let off the gas now, it will die. It takes approximately 1/8 of pedal to make it run.. then it will run close to 2000 rpm’s.

So something got worse, I just need to figure out what.

I’m off to get some fatheads to fish in the morning before working on this thing again!

If you think it may be a vacuum leak around the carb there is a very simple test for that. Just start it and spray carb cleaner around the base of the carb. If it has a leak the engine will rev up.