hi guys im new to the forum and i have a question about a dodge ram. all i know about it is it is a 318 (between 94-99, not sure of year). the owner says it ran poorly and now wont start at all. he put all new spark plugs/caps on it and distributor cap and still no go. he had it to a garage but they didnt know the cause (but they think it maybe the computer..), and because he bought another truck he didnt care if he fixed it. i was wondering if maybe anyone on here has ever had a similar problem and would be able to give me some advice. also i am getting the truck for free from a family member so no loss if i cant get it fixed :smirk:

Hey, llane,
I know enough to be dangerous, but I'd hazard a guess that the experts here might suggest that defective crank or cam position sensors might be the culprit(s)? If so, that's not death-spiral expensive?

i've been doing some research and have found that the plenum gasket is a common problem on these trucks, could this be a cause? unfortunately i do not have the truck in my possession yet so i cant check :bonk:. thanks for the help BSAVictor i'll be sure to keep that in mind.

spark with timing , fuel with timing and compression .

do you have these things ? asking what is wrong with it with out even knowing if your gettting spark or fuel is not going to get you very far .

i would start buy checking for spark and fuel . in my experience when a cps breaks it breaks , there is no poor running just no running at all .

there are several ways to check for a vacuum leak on the plenum , spray water or wd-40 , carb cleaner , ether , propane etc and watch for a rpm change . this is spraying at the suspected area .

could be a crankshaft position sensor. there isn't a camshaft position sensor on distributor type magnum motors. plenum gaskets do go on these motors, but usually just causes engine to ping, smoke and even poorer fuel economy. You need to run diagnostics on it to see if the computer has any malfunction codes.that's where i would start.
These are very good motors. i had 213k on a 93 dakota with a 318 and it still ran very well. i have 160k on a 98 ram and it is the best running vehicle i've ever owned, with the possible exception of my drz. this shouldn't be too difficult to sort out. if you can buy it right, i don't think you can go wrong. BTW, 96 band newer are obdII motors and are more desirable than 95 and older obd1 motors.
Good luck!

brad the best said:

i know i dont have much info, i will give more after i get the truck. i just want an idea of what im getting into here. thanks though.

clrwatrtom said:

thanks for the info! it's free, so imo i cant go wrong here.. and yeah i think it is newer then 95, but im not 100% sure. hopefully i will be getting it within the next week so maybe i will be able to get some more information to go on.

llane said:

its most likely something simple . i doubt its the actual ecm, if its subject i would unplug it and clean the connections, in my experience that is the #1 ecm problem .

clrwatrtom said:

I had understood that for this vintage there is cam position sensor in base area of distributor...?

ok i have found out that the truck is a 94 with about 140k kilometers. also it fouled some plugs in its running poor stage.

sounds like plenum gasket at the very least. Check out Hughes Engines. They have lots of info on MOPAR stuff, including magnum motors. the 94 has the old style computer, not as desirable as the 96 and up models. you can't flash the old style computers with a programmer like you can the OBDII computers

BSAVictor said:

if you research, you'll find that's not the case. The V10's have a camshaft position sensor, and i believe the deisels do as well, but not the 3.9, 5.2 or 5.9 V8s

clrwatrtom said:

already been lookin into the plenum gasket problem on dodgeforum.com, they say that oil in the intake is a sign and also if you take the o2 censor out of the cat and it starts its a sign. and yeah i was aware the 96 and up models are more desireable, but its not so bad as i wasnt really lookin to flash the computer anyway, oh well. im gonna check out those 2 things when i get it (which should be within next couple days:banana:). do you know how hard it is to change a plenum gasket with the hughes kit to fix it permanently? i'm only 15 and am just getting into this type of thing and was wondering if i would be able to do it myself? thanks for the help, i've given good gas (or w/e they call it since the new forum lol) to all who have commented!

clrwatrtom said:

It's not necessarily applicable to 94, but I checked and at least the 98 5.2 has cam pos sensor in base of distributor---source = ChryCorp shop manual.

llane, simple compression tests might be good, too; if oil changing was severely neglected, etc., rings might be bad---also, valves could be burned/guides worn... some items relating to fouling plugs...? Did PO take any care of rig at all? (Might be delicate question to ask on freebee?)

Also have heard of some models with this engine having significant amount of acid from wacko battery maintenence/bad replacement mounting job spilling onto nearby coil....don't know if that applies on this particular truck....

[quote name='BSAVictor']It's not necessarily applicable to 94, but I checked and at least the 98 5.2 has cam pos sensor in base of distributor---source = ChryCorp shop manual.

the camshaft position sensor is actually the pick up trigger in the distributor. it is referred to as a camshaft position sensor, but id doesn't come in contact directly with the camshaft, but gets it's signal from the distributor shaft. it functions like the points in an older non electronic ignition styled motor. Thanks for your diligence in clearing this up.

BSAVictor said:

yes, he did take good care of the truck. as stated before he is giving it away because he has another truck and its just in the way for him now. plus it helps that he is my uncle, lol

before you jump to conclusions on sensors and such check your basic engines necessity's to run. Spark, fuel, Compression/air. usually i have found it best to check those 3 functions in the order listed (vehicle type pending) and with a good ole magnum 5.2/5.9 its quite easy and in the long run will save you time and money :thumbsup:

1. check spark at the COIL! first while cranking the engine , and just not any spark a strong one (these particular motors have a forward mounted coil with exposed metal plates that like to rot in the rust belt and split the plastic housing) have seen many of mechanics dumbfounded as they "have spark", it just happens to be weak, i recommend buying a spark tester if your a newbe (fairly cheep at the local auto store) or if your brave use a plastic handled screw driver about 3/4-1 inch from a ground source (any bare metal) if you have a weak spark replace the coil, if you have a strong spark see #2 no spark see#3

2. check spark at a spark plug, again check for strong spark, if it was strong at the coil but weak at the plug you most likely need a ignition cap, rotor and ignition wires (basic tune up) also replace the spark plugs. if you have strong spark see #4 (EDIT) i see they already replaced them (cap rotor wires) but is good info to have for future diagnostics

3. you have no spark at the ignition coil while cranking the engine you will now need a 12v test light, there will be 2 wires running to the coil one will be 12V+ (i think its a green with a orange tracer those years)and the other will be the signal (a switched ground) wire from the PCM. remove the connector from the coil and with the ignition in the run or on position check for 12v+ with the test light grounded to the battery. if you don't have 12V+ it will be a wireing,relay,fuse issue, if you have 12v+ now change the test light ground wire to the positive terminal on the battery and while cranking the engine check the other wire (signal wire), the test light should blink as the engine is cranked over if it does not blink then it will now be a computer,sensor, wire issue, if it blinks with the engine cranking over and you had no spark at the coil replace the ignition coil.

4. spark plugs, remove a spark plug from the cylinder head and inspect the electrode (little bit of metal coming out of the porcelain) see the color and if its rounded over at its edges if it worn change them (quite easy and cheep) and see if the condition improves. if it does cool, if not see #5

5. check your fuel at the fuel rail, now i will assume you don't have a "fuel pressure gauge but at this point you really wont need one for basic diagnosis, on the fuel rail ( it is located on both sides of the intake plenum connecting the incoming fuel line to the injectors) you should see the "test port" will or had a black screw on cap over the port and will have a small valve in it like a tire. NOTE! before doing this test make sure u understand its the fuel rail and not a AC line otherwise you will remove refrigerant! wearing safety glasses,goggles depress the center of the little valve with a small screw driver, fuel should squirt out with the ignition key in the on position if it does not cycle the ignition key (off to on/run position) and try again if fuel does not come out of the port then the fuel pump is not working or the line is clogged and is another story (will explain if necessary later)

now if you have gotten this far with everything operating properly we can go into other aspects in another post but i highly recommended following the list provided before jumping to any major conclusions unless you feel the problem is truly something else and is staring you in the face. I have seen may of leaking plentum gaskets in my time (my 93 5.2 ram is still leaking hehe) but they NORMALY do not leak bad enough to cause a "no start" condition. as far as the cam and crank sensors go i still feel its good to go through the beginning of the list to "narrow down" your problem and come up with a clear conclusion of what the malfunction is. any questions also feel free to PM me if u like :ride:

Keith

the only reason i was gonna check the plenum gasket first is because it's relatively easy, but if i find this is not the problem, i will continue by completing the list above, and get back here with the results. i get a lot more/better info from here then the actual dodge forum haha, thanks!

llane said:

Print K19's info it is simple and complete also discount/cheap ignition parts aren't any better than old parts. On the intake plenum discussion when it fails it allows the engine to draw vacuum in the crankcase causing a lot of oil loss you can check this by removing the pcv valve and the other vent hose and putting your hand /finger over the holes and while running you will feel it sucking if the plenum /intake gasket is/are leaking. I doubt this would cause a no start the engine will run off of oily plenum air . My guess is coil wire wasn't changed or was switched with a plug wire I'm not a fan of dodges but with good ignition they start.

I hope like crazy it isn't what happened to my dodge ram. I had a 97 4x4 with the 318 (5.2). I was sitting in a parking lot with the engine running and it died all of a sudden. After days of trying to diagnose the problem, and replacing alot of parts that were'nt broken, I discovered that three teeth on the timing gear had chipped off and allowed the timing chain to slip. It took out almost the whole valve train, yet the engine would turn over like there was nothing wrong. 2,000 dollars later it was running again. Like I said, I hope you don't have the same problem. By the way, It only had 87,000 miles on it. My mechanic said he had never seen that kind of failure on such a low mile motor. Good luck.