Edmunds Answers


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  • avatar 0patience 06/29/08 3:15 pm PST

    Looks like your compression is good and you checked spark.

    I didn't see anything about the fuel pressure?
    Have they tried squirting fuel into the throttle body and see if it wants to fire then?

    Does it sound like it wants to fire, pop or anything?

    I would try primering with a little squirt of fuel and see if it wants to fire. If it does, then its definitely a fuel problem.


  • 0patience 06/28/08 6:39 pm PST

    It's not complex at all, just there isn't anything for you to adjust.
    If the cam sensor or crank sensor aren't cracked, then check codes with a scanner and let us know what you get.

    Check compression. Specifically, what did you get in each cylinder?
    Check fuel pressure. Specifically, what EXACTLY was the fuel pressure? How many pounds?
    Use a spark tester for coil on plug applications. How did you check for spark?
    If you used a screwdriver, there is a good possibility that you have killed the ignition module in the process.
    Are you certain that you have the plug wires correct?

    Let us know what you get.

  • docj 06/28/08 11:16 pm PST

    Here is a link that shows how to set everything...

    Hope it helps

    Doc J

    Source: http://www.autozone.com/addVehicleId,27

  • jif514 06/29/08 1:54 pm PST

    The engine is at a auto repair shop,he says compression is 130,checked all fuel injectors and are working porperly.He checked all 8 plugs with a spark tester all is good.We had programmer come in and check the the computer all is working just fine all sensors are working properly.On the outside there should be no reason why it will not turn over according to my mechanic,who besides himself has three other ASE certifide mechanics

  • jif514 06/29/08 1:56 pm PST

    By the way thanks for helping out

  • 0patience 06/29/08 3:15 pm PST

    Looks like your compression is good and you checked spark.

    I didn't see anything about the fuel pressure?
    Have they tried squirting fuel into the throttle body and see if it wants to fire then?

    Does it sound like it wants to fire, pop or anything?

    I would try primering with a little squirt of fuel and see if it wants to fire. If it does, then its definitely a fuel problem.

  • patrick88 06/29/08 3:37 pm PST

    If the spark and compression is good, computer is good that only really leaves two things
    1) Is it getting fuel, is the fuel pressure correct? Is there any obstructions in the fuel lines (i.e. clogged fuel filter etc..)
    2.) does it fire at all and just not catch? How about the air intake if so?
    If its at a auto repair shop and has 3 ASE Cert. techs, they should know how to deal with the timing and setup.
    It has to be fuel or air related. If the other items are good to go (spark, compression etc..)

  • jif514 06/29/08 3:52 pm PST

    They tried spraying fuel in the throttle body but it still won't fire all fuel injectors have been checked they have gone thru this engine with a fine tooth come to find the problen they had the truck now for two months

  • 0patience 06/29/08 9:10 pm PST

    What does a scanner tell them?
    What does te scanner say the timing is set at?
    It should give them the base timing.

    If the base timing shows correct on the scanner, then you know that the ignition timing isn't the problem.

    Again, does the engine spit, sputter, pop or try to fire??
    If it does nothing, then recheck the spark to the plugs.
    Even if the timing was way off, if you have proper spark to the plugs, it should at least pop and sputter. If it doesn't, then you have no spark or improper spark.

    One other thing that they should check.
    Have them swap out the ASD (Auto Shut Down) relay with spare or Condenser relay and see if it starts then.

    Check to make sure that the crank sensor and cam sensor have been properly installed and are not cracked or broken and that the connector is connected and secure.

  • jif514 06/30/08 5:38 am PST

    I will ask my mechanic about the base timing and the asd,I know it does not fire at all ,but he say they have spark, sensors were checked and wiring all ok

  • 0patience 06/30/08 10:48 am PST

    I gotta be honest with you.
    You may want to be thinking about having another shop deal with this.

    If your "mechanic" sprayed fuel into the throttle body and it didn't at least pop, sputter, cough or make some indication that it wanted to fire, then you have no spark.
    Plain and simple.

    I have to also wonder about the work that was done. If the crank or cam sensor were damaged on installation, then that could cause a no start.

  • patrick88 06/30/08 11:20 am PST

    I agree with Opatience,
    If they sprayed the TB with starter fluid (or whatever) it should've at least burped or bumped or whatever you want to call it :-), if there is spark present. Unless, and there is a very little chance of this, that the butterfly valve is completely shut blocking all incoming air/fluid.
    Just for the heck of it, see if it is opening and closing and if there is any obstructions. I only suggest this because it looks like just about everything basic has already been done (or has it?).
    There is no reason for your truck to be in the shop for this length of time. I can understand very difficult/challenging diasgnosic problems and they take time (been there done that), but not a week or so. If this shop has a decent diagnostic setup, qualified techs, and enough techs it should be out the door by now (except for the occassional part that is on order or a rebuild). I would go back in there and sit down with the service manager and techs and go over everything that has been done and get some answers. If not satisfactory, start looking for another shop. If these guys are really qualified and are really trying but can't get it right they would probably be glad to see someone else get it done for you. (I've had one or two things that I wasn't sure/qualified to do but tried and couldn't get it and then had someone else do it and was happy that the person got their car fixed, it made me mad that I couldn't get it (ego, and love a challenge)but the owner comes first!) If they are just milking you for parts and labor cost (more time on the diag machinces, techs etc..) they'll be against it. Test the waters and you decide.

    Another book by Pat :-)

  • bandit10 07/01/08 11:18 pm PST

    I have to agree with 0patience. Get your vehicle out of there. It's becoming an ATM for these mechanics. And as 0patience said they may have done some type of damage during the course of repair. 3 or 4 ASE certified mechanics and they can't find, and repair your Ram take it eslewhere. Your money is good all over town. As much as I like to save money, I think maybe this is the time to bring it to Dodge, pay the price once and for all. And enjoy your vehicle. I wish you the best of luck. I can only imangine your frustration hearing their stories of what they've done, and yet nothing has really ever happened to correct it. Please let use know the final outcome. We all share this site, and believe me we do care and we all learn from sharing stories.

  • jif514 07/02/08 6:34 pm PST

    Sorry for not getting right back work took me away .This will be the third different auto repair shop that has looked at it and all the same answers ,dealership here locally is out of the question

  • patrick88 07/02/08 6:49 pm PST

    Ok, you are at a new shop now (right?).
    Have them do all the basics again just to ensure that all that was reported by the other shops were correct and done.
    (a) Check fuel pressure
    (b) Check spark
    (c) Check Compression on all cylinders
    (d) Have a complete diagnostic reading done (Tech 2 and others)
    (e) Check air intake system
    (f) check timing

    It has to fall into one of these areas (unless your vehicle is named Christine :-) ).
    Has the shop done all of this? The gremlin has to be in one of these areas. I keep asking because I'm getting fustrated with all of this (just like you are) and there is no way that all of these Techs who are supposedly certified can not find the problem. (please note: after rereading this my tone seems like I'm doubting you, which I am not. It makes me mad and gives those of us who do this as an occupation a bad name. I wish I could get my hands on the vehicle to work it out!)

  • jif514 07/03/08 6:26 am PST

    No I do not think your are doubting me at all and before I sent the truck to this shop I made sure that they will perform all the tests that you guys have past on to me.I will talk to them today and see how the progress is coming they have had Christine for two days now.The last mechanic had outstanding references in my town as someone who could fix anything and some of the references I talked too back up everything that was said.He was upset that I moved the truck because he was dead set on getting that thing running but sooner or later the cost of parts so far is getting expensive and I am wondering about getting a rebuilt engine instead of dumping money down a hole.

  • patrick88 07/03/08 11:34 am PST

    Let us know what they tell you.
    I can understand why he's mad he's probably like me, once I get a challenging problem I hate to get pulled off of it (I'm pig headed and won't stop until there is nothing else to do or get pulled off, even then I hate it, but the customer/owner comes first). Your mechanic with references is probably a good one (especially w/all the ref's and rep) some times we all get stumped.
    This is a case of one of those rare occasions when something very small is stumping everyone. It does happen but rarely (I think it's possessed, if the radio turns on and the car starts rolling get out of Christine's way :-) ).
    I did talk to a few fellow Techs last night and we decided it has to be one of the above issues and something small and overlooked. It's very hard diagnosing over the computer without being able to see, touch, hear and driving.

    When you did the rebuild on the engine, what exactly did you do? What parts were replaced and were they OEM or aftermarket and correct? (should've asked this a long time ago). What caused you to do the rebuild? How long ago did you rebuild and how did it run right after (actually, did it run at all after rebuild, initial start up?)?
    Let us know the above and I will dig some more.
    By the way, what state are you in?

  • jif514 07/04/08 6:26 am PST

    The engine was rebuilt buy my brother inlaw he works at a engine shop that does valves cylinder sleeves pistons.It was done 6 months ago and since it was going to be rebuilt we did everything,pistons new heads,new timing gears & chain,fuel injectors,new sensors,basically everything is new except the block.I lost compression on two cylinders after 100,000 miles on it but Dodge had rebuilt it at 75,000 miles because of engine sludge and it was still under power train warranty.Well the new shop has done all the checking and it still will not fire,they say the same as before,compression,spark,fuel,sensors,w
    iring all is ok that it is not ingniting in the cylinders for some reason they want to take the front end off and look at it.I live in Southwest Fla.

  • 0patience 07/06/08 1:23 pm PST

    If the vehicle shows compression, fuel pressure, spark and everything, then the most likely culprit is the computer.
    This should be put on a quality scanner to monitor the values.
    If the values are all out of wack, then either the grounds to the computer or the computer itself is bad.

    You have confirmed that that the valves are opening?

  • patrick88 07/07/08 10:22 am PST

    Once again, I have to agree with Opatience.
    If everything mechanically checks out (i.e. properly installed, correctly timed/placed, correct parts, no poltergeists,, etc..) it comes down to electrical/computer like he said, check the computer to see if it is grounded properly, all fuses/relays/circuit breakers are good to go, and then have the computer checked.
    If it comes down to the computer needing replaced, check your local junk yard for the same year truck or a year either way. You could save yourself $100's (even 1000). Most trucks are there because of blown engines or wreck and the main computer unit isn't touched or harmed. I went to one yard to get a junk one to just to get the case and looked around and just about every vehicle (at least 8 out of 10) had a good unit in it. So whenever I have to replace one for a customer I always give this option. (ex. replaced 1998 camaro wiring harness and computer for a friend paid $15 for harness (had to remove it myself though) and I think the computer system was either $25 or $35, I know I walked out of there paying $75 (I also picked up a few other parts too).
    I'm running up to the local college today and will stop in and talk to the Head Instructor of the Autotech course and see what his ideas are (this guy is a wonder!!!).

  • jif514 07/07/08 8:07 pm PST

    The computer was redone buy a company out of Jacksoville Fla that has a lifetime warranty on it and the last mechanic had someone come in and checked the computer and it was working properly.The current mechanic has just retraced all electrical wiring and sensors and everything is fine with the wiring.He says for some reason there is no combustion in the cylinders even though it has spark.They are going to break down the front and take a look

  • waggawee 08/08/08 1:09 am PST

    Hey, i am new here and i would like a shot at trying to help out with your truck seeing that you have been going from place to places trying to get her going. I have read all what your friends have said, and those checks turn up as failures as the problem of nt starting persist. You have check cam and crank did you check the position sensor, this work with the timming. Have the timming re-check, you'll be getting compression but if the timming is off the compression will fire but wont start. You'll be getting gas and spark, so my suggestion to you is re-check the timming because the timming has alot to so with it. So get them to rotate and get # 1 piston up (tdc) and set the head timming and i am sure your christine will start up and purr. Let me know how it work out. ( waggawee ) That dont sound like electrical but mechinical problem ok.

    Source: Auto Electrican

  • scwrangler 08/09/08 2:53 am PST

    Hello-I worked for Dodge for 16 years until a stroke got me so my memory isn't what it should be, but just a suggestion. The flexplate/flywheel has small window openings spaced around it. On some engines the crank sensor must be lined up in the correct window to trigger the ignition process to begin. This may not help at all but it shouldn't take but a minute to double check. That engine is a combo effort between Chrysler and Mercedes and I do remember something about the timing being a pain. Double check the cylinder sequence when checking the compression. Seems like something on the SBEC has to be grounded out before the timing can be set correctly. Also that one has the coils mounted directly to the plugs doesn't it? One other thing make sure you have a good "non-painted" ground mount on both ends.
    Good Luck

  • jasonlives2 08/11/08 1:45 am PST

    First off, let me just say that after reading your posts and the responses, you blew me away! I have sitting in my driveway, a vehicle with the same exact symptoms! I'm an automotive and truck tech and have been for 20 + years, nevertheless I cannot figure this car out. I believe the problem may lean towards a vacuum problem but have yet to find it. Since it seems that you have been through practically everything one could think of, the only advice I can offer is check that the cats are not plugged. I hope you find the problem and post the solution so I might solve my own Christine. I'm stumped! lol

  • sflint 09/28/08 12:47 pm PST

    Any resolution to your problem? I just rebuilt my 2001 Dodge Ram 4X4 1500 5.2 liter after one of the heads cracked. I only had a correction hone done, crank polished, valve job, re-man head to repace the cracked one, and I put all stock parts in it, standard size bearings, etc. All tolerances were good. I have spark, fuel, good compression, and timing is good, as I did it myself. I squirted starting fluid down the throttle body -- nothing. Not even a backfire. However, I put back in the old cam and crank sensors. Also, I have P0601 code from the computer, which indicates "Internal Control Module Memory Check Sum Error." Haven't the foggiest what that means. Does the PCM need to be reprogrammed after a rebuild? Or do I need a new one? Any ideas? Thanks for any help....

  • eytcheson 11/06/09 8:24 pm PST

    He may have to open the front of the motor to check and make sure the v8 mark is at 12 oclock with double mark links of chain and the single mark link of chain is at 6 oclock for crank. as well the single mark in chain should me lined with point of R on right side and mark of chain lined with point of point of L on left side. the V8 marks should both be at 12 oclock on cam shaft gears. This is how I got mine to fire after replacing heads. You should be abel to see schemadic from your local shop.

  • dadsmobileshop 02/25/10 10:48 am PST

    the 2002 Dodge ram has 2 different computers onboard. One reads a 16 tooth cone wheel and the other reads a 32 tooth cone wheel, also they are two different wheels used on the left side shaft on the head. These items have replaced the dist. and allow the computer to read the wheels and fire a spark when needed. If the wheels are not correct it not run, however you will still have good compression, fire and fuel pressure. You need to check the cone wheel and the smaller wheel on the camshaft. The cone wqheel is on the back end of the crank shaft however you can see it if you use a mirror and look through the hole where the crankshaft position censor goes. The engine is easy to get into time use a pilot level and make sure the marks on the gears on the cams shaft are V8 at 12 oclock and the other two are at 3 and 9 oclock. Hope this helps out if you further assistanc you can call me if you wish at 678-373-9663.

  • latinosamg 03/20/14 9:15 pm PST

    your problem is your timing is off make sure they ran a compression check on every cylinder had same problem on customers truck the dowel pin on the camshaft sprocket had somehow sherred off and caused the timing to go off had compression try holding your hand over the throttle body and have someone cranck the engine if you feel air pushing toward you then your timing is off

  • ram64 12/20/14 11:50 am PST

    I'm pretty sure compression is suppose to be higher than 130 for the 4.7 but maybe not. Hope you get it up and going again

  • sandman799 02/23/15 4:23 pm PST

    I also am having problems with my 2002 Dodge Ram 1500 Quad Cab 4x4 SLT with 4.7 liter magnum V8, mine was starting and running perfect for the last several years and one day we tried to start it to get registered and only turns over but won't catch, I couldn't hear the fuel pump cycling on with the key so I replaced it but still won't start, it turns over strong but no indication of any kind that it's going to catch and like I said nothing changed or was touched between the two days, so fuel pump replaced and figured I would have to try starting it a few times before the pump was up to pressure and fuel injectors would push fuel to start but it didn't, I thought maybe if the battery wasn't charged enough to activate fuel injectors, I do know it's got spark and good fuel pressure and if I spray starter fluid into the throttle body it starts up immediately and runs strong for a few seconds and then dies and I can do this many times in a row and it'll start easy and run strong until starter fluid has burned up. If I press in on the fitting on the passenger side fuel rail it pushes fuel out strong even without the key on, what I mean is if I turn the ignition on and turn it off and then press in the center of the fitting on the passenger side fuel rail it spits out fuel. But after all this I am going to turn on the key and see if power is getting to the injectors with a meter and if they are getting power then I have no idea what else to check besides the cam and throttle sensors? One other thing I've been contemplating is maybe it's the alarm/remote start/keyless entry system because everything goes through the relays on the alarm system so if it isn't powering up the fuel injectors then it could be the problem and I will have to bypass the relays on the remote start and see if this fixes the problem? Anyone else want to weigh in on this? Oh yeah it's a 2002 truck with 42,000 miles on it, so it's got very low miles for its age and we've never had a single problem with this truck and we love it and need to get her running again but I wanted opinions before I go ripping out the remote start portion of the alarm system??


  • slickerg 02/28/15 2:18 am PST

    Well, I can surely feel your pain on this one!! I have a Jeep in my shop right now having very similar issues. Here is what I have learned over the past week of pure hell with this engine:

    Your problem is most likely in the timing chain. If you made the unfortunate mistake that I did and installed an aftermarket timing component kit you will need to have the factory sprockets put back in place. There are 2 different tone rings for the cam sensor. One is for the Jtec system and one is for the NGC system.

    An engine with the Jtec will have a 3 connector PCM (engine computer). NGC will have a 4 connector PCM. The cam tone wheels have different window patterns. So, you could have the totally wrong sprocket for the right hand head cam. However, I also have discovered that my kit had a sprocket that looked pretty much identical to the original factory one but still did not work properly.

    Plus, in the long process of dealing with this I have also come to the conclusion that the idler sprocket may not be completely lined up the same as the OE one is. With the aftermarket timing chain parts installed and the colored links placed at the corresponding marks on the sprockets, my engine had 150 psi compression on the right head and 175 on the left head. Moving the right had sprocket with the tone wheel one tooth clockwise (when looking at the front of the engine) the compression came up to 175 on the right head. However, this set the timing out of whack also and has caused the coils to all fire at once and blow the ASD relay fuse.

    So, the only solution is to use the factory timing sprockets and use extra care to set the timing correctly. I don't know how to post the setup pic but any pro shop will have access to that info.

    I noticed that when the right cam sprocket is set correctly, the cam sensor should be lined up with about half of one of the tone wheel windows (it will be a 2 window set that is close to the end of the sensor). When I had the right cam advanced one tooth, the sensor end was lined up with a solid part of the tone wheel, just past this 2 window set.

    If the timing in your engine has been off already, the ASD fuse is likely blown. Make sure they check that. My engine was also setting ignition primary codes once it ran with the OE tone wheel installed but advanced one tooth.

    I really hope this helps! The timing setup on this engine is really poorly designed. The procedure to line everything up is too ambiguous. The manual says the v8 symbol on the cam sprockets is supposed to be at 12 o'clock when the crank is at #1 top dead center. However, they don't seem to really be at 12 o'clock no matter what you do. They are either a little bit before or a little bit after. And, in this case I believe the right cam should be a little before 12 and the left should be a little after.

    I have taken the front cover off of this POS 3 times now and have to do it again tomorrow! I would have had zero problems if I had used all OE parts for the timing kit. Hard, expensive lesson learned! Good luck and let us know the outcome.

  • sandman799 09/14/15 12:10 pm PST

    I also have a 2002 Dodge Ram 1500 with the 4.7 liter engine, everything checks out, fuel pressure, spark and everything else, I can spray starter fluid into the throttle body and she fires right up and runs strong and smooth for a second or two and then dies when fluid burns off, I've replaced fuel pump, cam sensor, crank sensor, throttle body sensor and checked injectors with noid tool, and fuel pressure at the fuel rail test port, it has a remote start and alarm system that have been in it since new but I thought maybe it was the remote start portion of the alarm maybe causing the no start, so I removed that part of the alarm system from the truck so all functions are direct wired again instead of going through the remote start module and still no start? Like I said I've replaced everything that people say can cause this problem, it just makes no sense for it to start perfectly and run strong and then a couple weeks later I go to start it and just cranks and cranks and cranks but won't fire unless I spray starter fluid into the throttle body and then it fires up immediately and runs strong until fluid is burnt up? I know it's gotta be something simple because I've replaced the components that would normally cause this problem and none of the parts made a difference at all, I thought there might be a fuel shutdown switch that if it gets tripped this is what happens, I actually had a vehicle a long time ago that had the fuel shutoff switch that would shutoff fuel in the event of a crash or something like that but it tripped and it acted just like my truck is now except it had a physical switch that you just pushed back in to reset it and get fuel running again and the car started right up, so anyway yeah everything works as it should except it will not allow fuel into the cylinders to fire, but haven't found any reference to a fuel shutoff switch for my truck? I've also scanned the computer for codes with my OT2 OBDII scanner and everything looks good as far as the scanner can tell and there haven't been any codes generated at all, What about the ASD relay? Is that the same as the fuel shutoff switch? Where is the ASD relay and how do I test if that is causing the problem or not? Please someone help me, I'm a fully disabled veteran and need this vehicle to start so I can make my veterans appointments at the VA hospital, I just don't know what to do to get this thing running and there shouldnt be anything that is stopping it from starting? I do remember my wife telling me that our nephew was screwing around under the dash on the drivers side and before that it was starting fine and I've looked under the dash thoroughly and don't see any damaged wiring or anything that looks out of place, or at least I don't see anything obvious so it could just be a coincidence? So anyway someone please help me, I'm at my wits end on this one and need my truck running again

    If it is the timing being off would it still start and run strong when spraying starter fluid into the throttle body? I mean you would think that if the problem was the timing then it wouldnt start even with starter fluid would it? Or would it still start with spraying gas or starter fluid into the throttle body even if the timing is off?


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