My dad has a 2001 ram 1500 with the 5.9 gas engine. So about 2 weeks ago my parents said it wouldn't start and trying to piece together my dads story, he has problem describing things, but I guess he ran the battery down trying to start it, then he charged it and it started but ran like shit and in his words it would "only idle at 5000 RPM" and if he let off the throttle it would die. ( I told please let's try not to put a rod through the block doing that!)

So I went over and was all preppared to work on it........ it started right up and ran fine It had 1/4 tank of gas and had been sitting for about 2 weeks, so I put seafoam in it and cleaned the battery cable (couldn't tell from dads description if it had a dead battery or if he ran it dead trying to start it) I drove it to work 50+ miles a couple times and topped off the gas tank. No problems at all.

So now it sat for a week or so and yesterday he loaded it up with trash and went to leave and said it wouldn't start, so today I came to look at it again and I just reach in and turn the key and it starts right up.

He says that when it does this the ABS light comes on, but not the engine light. I didn't check codes, but no engine light.

My mother said it started running real bad on the freeway a while back (like it was the time he got it started) and they pulled into a truck scale and then it suddenly ran fine again.

I bought cap, rotor, plugs and plug wires, will install those. Does any body happen to have expieriance with this type of symptom?

UPDATE:
I got the crank position sensor, cam position sensor, cap, rotor, plugs and plug wires replaced. It has sat for over a month and has less than a quarter tank of gas. I started it up and it kinda ran rough, so much so I suspected I had gotten crossed plug wires, a double check showed I had them right. Upon starting it the second time it sounded smooth. I let it idle and warm up then took it out to test drive. I drove like 2 miles down the road and turned around and gave it full throttle and it started hesitating bad, like cutting out or miss-fireing. Only at wide open throttle. So I pulled in and shut it off and put STP gas additive in the tank (thought it could have water in tank from sitting), tested again and it ran great. Drove 15 miles and did a lot of WOT acceleration....... then on the last run the engine light started blinking (at WOT) when I backed off it quit blinking and went out..... still running fine mind you. I checked and got no codes. Does the engine need to learn the new sensors or something?

The blinking engine light could be the transmission. We've had problems with it and I was pushing it pretty hard, but whatever it was it went out on it's own.
2nd update!
Now on the way home I got code 0351."Iignition coil A primary or secondary circuit malfunction". Does this meen I probably need a new coil? Or?
I drove it 65 miles and it was running GREAT then in the last 6 miles it was missing.

My first thought with only running at very high idle is air bypassing the maf. That could be a sticking egr or a cracked intake tube.
I don't work on many dodges but I think this may be one of the models with bad power centers. That would cause your problem and might be covered by a recall.

Dodge can read it's own codes.  If I remember right, turn the key on, off and on again and it should throw a code where the odometer reading is.  You can find code definitions on Google.

while, it is unlikely the issue, as I have never heard it go away and come back, those engines are known for a bad gasket at the bottom of the intake.

the intake is a cast piece and the bottom is open. they seal it with a plate and gasket. the plate expands and contracts at a different rate than the intake. so eventually it leaks.

with a flash light you can look down the throttle body and look at the bottom of the intake, you will see if it has sucked up oil and burned it a bit.
this causes a vacuum leak and gives you erratic idle or bad idle, and I have heard of misfires.

however this would not account for a no start, unless the leak was so bad, the iac couldn't shut down enough.
that would probably be the second thing I would look at is the iac, see if it is bound up.

if you can get it to no start, I would check and see if there is a spark or not. just to help narrow it down.

throttle position censor

my 03 jeep does this. It's affectionately called the "key dance"

key off, key on, key off, key on I think is how it goes. I haven't checked mine recently

I checked codes, it just says" P   DONE". I tore oout the pluge wires and trying to replace the dist cap Legs are cramping up trying to stand under the hood. Had to stop. Crawled out from under hood and collapsed. Why couldn't dodge put the distributor up front?

Sounds like an air issue, check idle air control, maf sensor, look for leaks between the maf and the heads, this could include a bad intake gasket.

If I remember correctly the cam position sensor is at the base of and inside the distributor cap, this can cause the problem you're talking about and as mentioned earlier the intake had a known issue with a leak at the base. Also working off memory when the battery dies completely it tosses all its learned fuel trim, timing, etc and defaults back to mapping that blows chunks, it will run extraordinarily rough at first and must be kept at high idle or it will die. After a few miles of actually driving (not just running in your driveway) it'll readjust and run fine!

I have a buddy with an 01 5.2 and an 02 5.9 that were both having issues where they'd fall on their face, pop a bit etc, then all of a sudden go back to running fine. Some days it would happen a lot, other days it would be fine. Ended up finding the crank position sensor was junk, as in literally falling apart, replaced it and all was good. Thinking the same thing might be the problem with the 5.2, I pulled the crank position on that one and... junk. Replaced that one and it's been fine as well.

Not super difficult to get to, but if you have bigger hands you'll be exercising your vocabulary as it is in a bit of a tight spot.

that is on the back of the motor, bolted to the transmission housing.
might be a pain to get to without a step stool.

I have seen GM 8.1 motors with bad crank sensors give those same symptoms. Both times the part was falling apart and a bitch to get out. Maybe they use the same part.

Those were tough to diagnose as well.

I had a 99 Ram with the 5.2 doing similar things to me, until it left me stranded at a gas station. Ended up being the IAC (idle air control) valve/sensor.

In order of likeliness:

Crank position sensor.
Pick up coil (in distributor)
AIC

The bad (I gaurentee it's bad) belly pan gasket in the manifold will not cause any problems in starting.

Thanks. I think we are getting somewhere now.

When I had this with the gm 8.1s I was getting code's for the transmission. I think that was because input and output speed signals did not match. I got no codes for the speed sensor. The trouble shooting tree in the factory manual led to the sensor. When I tried to remove it it was broken. The replacement part was a different design.

When mine did that, I replaced both the cam position sensor and the crank position sensor. That was a fun time!

You can see it - or you can touch it. But you can't both see it and touch it at the same time.

Mine was always the crank sensor. Learned to change it on the side of the road by feel since you can't see the damn thing. Seemed like it happened 2 or 3 times a year

Looked it up in Haynes manual. Yeah, I can't see it. Can it be reached from undernieth easier

Through the wheel well (may have to remove the wheel wheel liner) and the wheels turned was easiest for me.  (This was on a Dakota - but same engine / location as yours).

You can see it from underneath, but you can't really work on it from there. It is useful to crawl under there and eyeball it just so you will know what to feel for from the top side.

A longish hex (Allen) bit for your ratchet is handy. Sorry, but I can't remember the size.

You can plan on mostly laying on top of of the engine and using only your left hand to work on the sensor. It is a bit like putting you hand through a jagged maze and you will have your shoulder against the engine unless you have arms like a gorilla.

The 2001 RAM factory service manual in PDF form is available online if you hunt for it.

UPDATE: So since I posted, I have so far managed to get the cam position censor/cap/rotor changed. I can only squat under the hood a few minutes before my legs cramp up.
Can not see the crank censor AT ALL. Thought I felt it today, not sure. No idea how the hell I'll change that.

INFO for others: the cam position censor (that is what Haynes calls it also), you will have trouble getting one at an auto parts store unless you ask for a "distributor pickup"
NAPA was no help. A very knowledgable counter guy at Knechts took the time to google search it and find out what the other name for it was.

Sorry, I didn't think to mention that.




I stuck my cell phone down there and took some pictures. That helped a lot with with having an idea of what I should be feeling for. A telescoping inspection mirror helps also.

Lay face down, stretched out on the engine and you can reach it.

Heck, I told you that a few posts back!  

Sorry, didn't notice.
My legs are still sore from squatting under the hood the other day. I figure one more weekend to do the plugs and wires, one more weelend to do the crank sensor (If I'm lucky)

BTT. update in OP.

Did you run the wires correct?  I mean - really correct?  Wires run incorrect can cause cross firing, which will cause misfiring....which will cause your engine light to blink.

Check here: Wire TSB

ETA: Blinking check engine light indicates problem that can damage the catalytic converters.  This is typically a misfire condition.

Light is out now. Runs better than ever. Touch the throttle and I'm doing 90! I hope I solved whatever was wrong, but only time will tell since it was intermitante anyways.

ETA: Now on the way home I got code 0351."Iignition coil A primary or secondary circuit malfunction". Does this meen I probably need a new coil? Or?
I drove it 65 miles and it was running GREAT then in the last 6 miles it was missing.