Switching cam shaft to fix fuel pump on 1988 Dodge Dakota

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Old 03-07-2013 | 06:58 PM
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Switching cam shaft to fix fuel pump on 1988 Dodge Dakota

I have a 1988 Dodge Dakota, it came with a v6 but my friend's uncle who i bought it from had put what he said was a "boat engine" in the Dakota. It seems barely used and it appears to be a 318 to me, I have no real clue what year it is.

My issue though is my fuel pump stopped working about 5 months ago as I was driving. I knew before hand the engine was getting starved intermittently.

I put on about 3 brand new mechanical fuel pumps, no difference. I started using an electric one I got from an '89 Dak but it just never meshed up. Either it pumped too hard or the regulator didn't regulate down enough or the carb would overflow even at the lowest setting.

I got it running today, a bit of overflow, I had to keep my foot on the gas the majority of the time, and if its not cranked up successfully in the first one or two turns it kills any battery I put in it. Sometimes I get five. I have to turn the light switch I have fired to the pump on for a few seconds to feel the carb.

What I want to know is:
1. how does one check a cam shaft to see if its so worn it can't operator a mechanical fuel pump?

2. Is it even common for cams to get so used they just get worn down and cant reach the arm anymore on the pump?

3. How much do I have to remove to switch these cams out? I am getting in too much trouble breaking my cars down where I live and need to kinda rap hings up quick. Is it as simple as unbolting the engine mounts, jacking the engine up, taking the oil pan off and pulling it out?

4. I have found several new camshafts in my price range but they have different numbers. One says "318 360 .441"/.441" Lift 6901" while the other says "SB LA 318 360 .420"/.442" Lift 6900 (Fits: Dodge)"
and I wonder what that means, what the specifications on my camshaft are and if I can just interchange these camshafts and it work? Or is timing altered? I am just tired of dealing with the constant autowork and the excess gas use, and the fiddling with light switches and wiring and hoping the battery doesn't die.


I have been told the eccentric that engages the fuel pump arm is worn down, bent, etc. How do I check this out?
Old 03-07-2013 | 07:16 PM
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If it is a boat engine there is no way of telling what cam is in there. The link below is for a pump that I have used in several application. Doesn't draw a lot of power and will feed a 318 easily.

You can not use a fuel injected fuel pump for a carb without altering the flow significantly.


http://www.summitracing.com/parts/hl...01-1/overview/
Old 03-07-2013 | 07:30 PM
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Originally Posted by PK1
If it is a boat engine there is no way of telling what cam is in there. The link below is for a pump that I have used in several application. Doesn't draw a lot of power and will feed a 318 easily.

You can not use a fuel injected fuel pump for a carb without altering the flow significantly.


http://www.summitracing.com/parts/hl...01-1/overview/
Yeah I have come to find out this pump from this 1989 Dakota I am using is from a fuel ejected Dakota. I am just wondering what I can fix in this engine so that I can began utilizing mech pumps again exclusively? I have asked on other forums ad on the Dodge site it finally reached a discussion about an "eccentric" in the engine that hooks to the mech fp arm. How can I inspect that and do I have to dissemble the whole engine?
Old 03-07-2013 | 07:32 PM
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thats all im trying to use right there, the old school style pump.
Old 03-07-2013 | 08:17 PM
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Nice big block pump. Get the small block pump and it will probably work just fine.
Old 03-07-2013 | 08:35 PM
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I aint stupid, i already know about the arm length, the pic was just to show a mechanical pump in general as opposed to a elec one..
Old 03-07-2013 | 08:57 PM
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Well how was I supposed to know that?

The eccentric bolts on the end of the camshaft with the same bolt that holds the timing gear on. If one has come loose the other is sure to follow. Changing the cam wont help but changing the timing chain with a new one would probably be a good idea if your gonna remove the water pump and timing cover to see whats going on.

There is stampings under the head on the drivers side with numbers and such that will help locate what the engine is, year, and any internal mods from factory. Probably need a wire brush to clean them off to read though.

Note: If it did come loose you got a mess in there that should be looked at as the material for the eccentric is hardened steel that can jam the chain and break it. Probably need a new eccentric, timing chain and sprocket assembly anyways due to damage.

You could change the cam but I don't see a reason to.
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Old 03-07-2013 | 09:06 PM
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The cam for the fuel pump is bolted onto the cam in front of the timing chain So unless the bolt is loose it will work !! WITH THE MOTOR OFF you should be able to kook into the fuel pump hole to see if it is loose DO not try and use a fuel injection pump way too much fuel pressure. Just use a fuel pump from any carbed 318 motor
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Old 03-07-2013 | 10:56 PM
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Originally Posted by jacilynn_s
The eccentric bolts on the end of the camshaft with the same bolt that holds the timing gear on. If one has come loose the other is sure to follow. Changing the cam wont help but changing the timing chain with a new one would probably be a good idea if your gonna remove the water pump and timing cover to see whats going on.
Is the eccentric attached to the timing chain sprocket or is it something thats behind the timing chain gear and timing chain? I can definitely change this eccentric out just by taking off the timing cover and water pump because I know the cam shaft protrudes from the head a little bit and has a few things on it such as the timing gear. You believe there is a high possibility the t gear, t chain, and eccentric all three need replacing? I know how to inspect the t chain and see if its lose or wobbly.
There is stampings under the head on the drivers side with numbers and such that will help locate what the engine is, year, and any internal mods from factory. Probably need a wire brush to clean them off to read though.
Yea I definitely need to get that info so that I can start using a manual thats closer to what I am working with. A Dodge Ram D250 guide as opposed to say an '88 Dak guide. The Dak v6 probably was way more electrical anyways explaining the fuel pump debacle.
Note: If it did come loose you got a mess in there that should be looked at as the material for the eccentric is hardened steel that can jam the chain and break it. Probably need a new eccentric, timing chain and sprocket assembly anyways due to damage.

You could change the cam but I don't see a reason to.
If it did get jammed in whats the full extent I need to examine though? Does the damage just stop behind the t chain cover or extend into the engine? I don't mind buying either 3 of those just because. I only need to know if adding a sprocket requires an engine break down. If you can JUST have a broken eccentric?
Old 03-07-2013 | 11:01 PM
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Originally Posted by TVLynn
The cam for the fuel pump is bolted onto the cam in front of the timing chain So unless the bolt is loose it will work !! WITH THE MOTOR OFF you should be able to kook into the fuel pump hole to see if it is loose DO not try and use a fuel injection pump way too much fuel pressure. Just use a fuel pump from any carbed 318 motor
If its lose its gotta be replaced though right? Its pretty hard to get a view in the side I guess because this engine doesn't belong in this bay. Am I literally looking for a lose cam or am I prodding at it to see if it moves or what?
Old 03-08-2013 | 02:45 PM
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Go to autozone they sell a universal electric fuel pump. It will run any stock small block. No regulater needed
Old 03-08-2013 | 07:14 PM
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Originally Posted by PURPLE HORONET
Go to autozone they sell a universal electric fuel pump. It will run any stock small block. No regulater needed
If the eccentric is broke I want it fixed anyway. Like I said I am just plain through with the elec pumps and don't have the money for 'em anyway. I just want to keep it stock, not drop the tank anymore, not use anymore battery juice that doesn't have to be used.
Old 03-08-2013 | 09:09 PM
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what hornet said. 2x
Old 03-08-2013 | 10:04 PM
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Originally Posted by moe7404
what hornet said. 2x
noooo moorrreee electric pumppp...
Old 03-09-2013 | 03:47 AM
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with the fuel pump off could you see inside? No not unless you have a tiny camera on a flexible shaft with a light even then it wont tell you much of anything. You might be able to put a screwdriver in there and see if its loose if the engine was out of the vehicle on a stand but highly unlikely.

The electric fuel pump only fixes the problem and not the cause which is the proper way to fix things. The small block engine is build with the cam sitting flush with then end of the block. A plate is then bolted over this to retain the cam shaft. A timing gear is then bolted to the end of the camshaft were a pin sits out so that the cam gear only goes on one way. The pin does not stick all the way through the gear as the cam eccentric has a small tab that sits in there. The bolt that holds the cam gear also holds the eccentric.

If the eccentric is turning on the cam it means the bolt has come lose already, The tab on the eccentric has either cut the aluminum on the cam gear or broken off already. Chances are that any aluminum or chunks are already in the timing chain and causing a mess.

To inspect you remove the pulleys and brackets after draining the radiator completely. Remove water pump and then the water pump housing. Warning the upper bolt on the water pump that goes directly to a tab on the top of the housing likes to seize and then break.

With covers off you can see what has happened. It is possible that the cam bolt has not come loose and that eccentric has broken clean off the motor sitting in the oil pan. Possible but not likely.

New timing gear sets can come with a new crank gear with offset keyways. These keyways allow for you to centerline a cam in. If you havent done it at least once before and have all the tools just stick with the standard 0 degree and leave it.
Old 03-09-2013 | 06:15 AM
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Originally Posted by D.j. Kellogg
I have a 1988 Dodge Dakota, it came with a v6 but my friend's uncle who i bought it from had put what he said was a "boat engine" in the Dakota. It seems barely used and it appears to be a 318 to me, I have no real clue what year it is.
-That in foe is important

My issue though is my fuel pump stopped working about 5 months ago as I was driving. I knew before hand the engine was getting starved intermittently. [/QUOTE]

-How long was this symptom going on?
Are you sure the fuel lines are not plugged, the fuel filters are clean and are the fuel lines the right size for v-8 ?

I put on about 3 brand new mechanical fuel pumps, no difference. I started using an electric one I got from an '89 Dak but it just never meshed up. Either it pumped too hard or the regulator didn't regulate down enough or the carb would overflow even at the lowest setting.[/QUOTE]

-Check the fuel lines... blow some air through them to make sure there is no dirt in them or there is dirt in the tank it may have to be removed and cleaned.
if the fuel regulator is adjustable too 7psi and the return fuel line is not plugged And the Needle Seat valve in the carb is not worn?... Check it.
It should not flood if the needle seat vavles is worn then fuel will blow right past it flooding your motor.

I got it running today, a bit of overflow, I had to keep my foot on the gas the majority of the time, and if its not cranked up successfully in the first one or two turns it kills any battery I put in it. Sometimes I get five. I have to turn the light switch I have fired to the pump on for a few seconds to feel the carb.[/QUOTE]

-Are you sure the vehicle was starving for fuel? Referring to your first paragraph, or maybe it was flooding?
Any battery doesn't mean there good. A brand new battery with the proper cranking amps for your motor size will not run down in a few cranks of the starter unless your have a MAJOR SHORT! What condition are the battery cables in?

What I want to know is:
1. how does one check a cam shaft to see if its so worn it can't operator a mechanical fuel pump?[/QUOTE]

-Take the bottom off the old fuel pump this will expose the diaphragm and pump arm re-install it have some one crank it while you apply upward pressure on the pump arm if the eccentric is there you will feel it pushing on the arm

2. Is it even common for cams to get so used they just get worn down and cant reach the arm anymore on the pump?[/QUOTE]

-I have never heard of one wearing out like that and if it where to break off it would make a hell of a noise bouncing around inside the timing chain cover until it jammed up against some thing and breaks your timing chain and gear set

3. How much do I have to remove to switch these cams out? I am getting in too much trouble breaking my cars down where I live and need to kinda rap hings up quick. Is it as simple as unbolting the engine mounts, jacking the engine up, taking the oil pan off and pulling it out?[/QUOTE]

--You will have to remove the accessories and the radiator the intake manifold the water pump/timing chain cover the valve covers the rocker arms and push-rods
the oil pan does not have to be removed.

4. I have found several new camshafts in my price range but they have different numbers. One says "318 360 .441"/.441" Lift 6901" while the other says "SB LA 318 360 .420"/.442" Lift 6900 (Fits: Dodge)"
and I wonder what that means, what the specifications on my camshaft are and if I can just interchange these camshafts and it work? Or is timing altered? I am just tired of dealing with the constant autowork and the excess gas use, and the fiddling with light switches and wiring and hoping the battery doesn't die.[/QUOTE]

-Early model L.A. small block motors or late model magnum blocks we are not sure what year your motor is so this needs to be confirmed, photos or get under her and look up on the bottom starter side of the block, also the intake bolts on l.a. blocks will be at an angle the magnum will be straight down into the manifold. the cams you list are fine as far as lift the lift will be limited to the valve springs if they are stock i wouldn't venture too high in lift maybe a 268 dur. 454 lift with out the proper valve springs though you could start new problems.


I have been told the eccentric that engages the fuel pump arm is worn down, bent, etc. How do I check this out?[/QUOTE]

You got your work cut out for you on this one.

Last edited by Gorts 5th; 03-09-2013 at 06:25 AM.
Old 03-09-2013 | 06:21 AM
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the last post i just took it one question at a time
Old 03-09-2013 | 06:52 PM
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Originally Posted by jacilynn_s
The small block engine is build with the cam sitting flush with then end of the block. A plate is then bolted over this to retain the cam shaft. A timing gear is then bolted to the end of the camshaft were a pin sits out so that the cam gear only goes on one way. The pin does not stick all the way through the gear as the cam eccentric has a small tab that sits in there. The bolt that holds the cam gear also holds the eccentric.
Yea I remember seeing the end of the cam shaft in the past and how it was set up to how things would only go on in one position on the circle.
If the eccentric is turning on the cam it means the bolt has come lose already, The tab on the eccentric has either cut the aluminum on the cam gear or broken off already. Chances are that any aluminum or chunks are already in the timing chain and causing a mess.
But this type of damage only requires a new eccentric and/or cam gear? Not a new cam outright?
With covers off you can see what has happened. It is possible that the cam bolt has not come loose and that eccentric has broken clean off the motor sitting in the oil pan. Possible but not likely.
Are you saying that if the bolt did break in addition to obviously a new bolt would have a tap in die job to get it fixed?
New timing gear sets can come with a new crank gear with offset keyways. These keyways allow for you to centerline a cam in. If you havent done it at least once before and have all the tools just stick with the standard 0 degree and leave it.
Does it need to be centerlined? What are the benefits of that? What is the zero degree? What the gear is on right now since it gas to be on that one way?

Originally Posted by Gorts 5th
-Are you sure the vehicle was starving for fuel? Referring to your first paragraph, or maybe it was flooding?
Any battery doesn't mean there good. A brand new battery with the proper cranking amps for your motor size will not run down in a few cranks of the starter unless your have a MAJOR SHORT! What condition are the battery cables in?
Its done both. It starved for fuel when it 1st started dying on the roads before I modified. Its starved twice after the elec pump was put on, the majority of issue has just been fuel coming out of the carb from the top and between the gaskets. Now I know its just too much pressure. The cables look already, no corrosion, still copper colored. I was using the smaller battery from my taurus w/o incident and during the times I had just got it. I got another battery here at 890 CA. I guess I can do a full inspection of them though.
You got your work cut out for you on this one.
If its at the end of the cam and behind the t chain cover it should be easy after I take a few other things off.

But like I had asked before after these items are all replaced I am in the clear with mech pumps from here on out?
Old 03-09-2013 | 08:58 PM
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IF the bolt came loose you would need to replace the cam gear, timing chain, crankshaft gear with a new set (comes in kit). Replace the eccentric if broken or the tab is fubared.

Highly unlikely the bolt sheared off into the cam but if it did you can remove it easily enough. I like to use a piece of tin with a hole drilled in it to protect the surfaces. Next I use a small rod 3/8 or a long 3/8 cheap bolt. Weld the end of the broken bolt to the rod and turn out. The trick is to not weld on anything but the bolt. You leave the weld only cool enough so that it's not super red hot. While still hot twist out.

Centerlining a camshaft requires that you know what the centerline is. On a used engine camshaft this is near impossible to do. Ive done it by searching some of my older manuals that had the centerline stated for the engine but it's not always easy. Measuring cam lobe heights and duration inside an engine is tricky as hell. Once you have the information(if your lucky the cam has numbers stamped on the visible end) you can find out what cam it is in charts and therefore the centerline.

The advantages to a centerlined camshaft are increased performance, fuel mileage and even correct ignition timing. The vibration damper has timing marks on it which are not always sitting where they should be after 40 years.

I had one 383 come it that was rebuilt. Brand new mopar perforance magnum cam. Timing chain and gears were brand new. The engine could barely get out of it's own way, used tons of fuel, and ran like absolute crap. We put centerlined the camshaft in and found the new timing marks were actually 4 degrees off. We also found that the timing mark on the damper was off by 10 degrees. With cam centerlined and all reassebled along with a new mark on the damper the car laid blackies for a 100 feet at 3/4 throttle. Fuel milage of the car went from 12 - 24. She also ran smooth at all engine speeds. This however was an extreme case. Most of the time a timing chain and gear set is almost spot on so just put a new one in.
Old 03-10-2013 | 04:17 AM
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Originally Posted by jacilynn_s
IF the bolt came loose you would need to replace the cam gear, timing chain, crankshaft gear with a new set (comes in kit). Replace the eccentric if broken or the tab is fubared.
http://www.ebay.com/itm/Timing-Chain...14a0e7&vxp=mtr
So basically buy that and the eccentric. I can get the ecc for like 39 bucks and that timing chain set for 27.


Centerlining a camshaft requires that you know what the centerline is. On a used engine camshaft this is near impossible to do. Ive done it by searching some of my older manuals that had the centerline stated for the engine but it's not always easy. Measuring cam lobe heights and duration inside an engine is tricky as hell. Once you have the information(if your lucky the cam has numbers stamped on the visible end) you can find out what cam it is in charts and therefore the centerline.

The advantages to a centerlined camshaft are increased performance, fuel mileage and even correct ignition timing. The vibration damper has timing marks on it which are not always sitting where they should be after 40 years.
Do they usually not have numbers on the lobe or do they kinda just get rubbed off on most engines after awhile? I still gotta figure out what is 318 came out of and its build year period. Centerlining cam shaft kinda sounds the same as lining timing marks up when finding tdc. But basically centerlining is figuring out what position the lobe is pointing in before you put the timing chain back on? Like is the lob supposed to be at 12 o clock, 1 o clock, etc. Thats what I interpreted centerlining as.
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