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Discussion Starter · #1 ·
hi there 1st let me start off by saying that i have owned my 2nd gen ram for a little over one year now, and i drive it everyday for the past year, one problem i had from the start was a miss fire in cylinder 6 all the time and sometimes had a miss in cylinder 1, so my truck doesnt smoke at all so that tells me the rings are good and would have to be a bad valve or valve seat, so i replaced both cylinder heads with remaned heads ok, tryed to start motor and ran very good no miss fire codes and about the time i said iam done the motor cut off and would not start back up, so i start to do some tests like check for fire, getting great fire, checked to see if fuel pump was working fuel pump is working, checked fuel pressure and fuel pressure is at 45psi which is good, checked compression all cylinders have around 120 to 140psi, come to find out that my crank shaft sensor wire was bad, replaced sensor and tested started right up no problems, i ran the truck for about one hour getting all the air bubbles out of the cooling system and rechecked to see if any codes had come back and nothing now i was done so i thought, the next day i start the truck up runs great for 5mins then cuts off and doesnt want to restart again, i waited about 10 mins and retryed again and ran for about 3 to 4 mins and cut back off, any ideas would be helpful thanks
 

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Is the truck getting hot? Or an air bubble in thermistat fooling temp sensor? Or short in crank sensor wires still?
 

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Discussion Starter · #3 ·
temp gauge show running warm but is not help please

the temp guage inside the truck says its running at about 225, but i have a lazer temp guage and took reading off of the heads both sides, water pump, thermosat, and top rad hose, and the block and all over these areas got a temp of 180 to 190, so no not running hot, and i installed and brand new crank shaft sensor i have not rechecked it yet, iam wondering if my wiring harness is bad from moving it back and forth when i did the heads, its almost sounds like the injectors are shutting down all at the same time, and i got another question wouldnt my obd2 pickup a bad crank sensor because befour i got the new one i unpluged it and try to start to see if it would pop up a code and it didnt, and do you know if it will pop up a code for a bad cam sensor
 

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Interment short might not set codes. But if anything move harness check plugs and temp sensor. If any codes come up it might be temp. That seems like a big difference from dash to engine.
 

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The computer has a lag time and will ignore interment problem for a piriod of time.
 

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Discussion Starter · #6 ·
temp gauge show running warm but is not help please

i did stop by the the parts store today and got a new temp sensor so i will see if that fixes the guage problem, and if anything like you said move the wire harness a little, if i do find a problem with the wiring harness do you know of a place that makes them or where you can get one, iam thinking of going to pull a part and see if they have one,
 

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Discussion Starter · #7 ·
temp gauge show running warm but is not help please

would like to have a brand new wire harness that wouldnt cost a arm and a leg lol
 

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Another thing after a night of sleep why didn't think of it fuel relay:thk:
 

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Well it seems if it holds pressure with no flux.don't think its pump on its own. It should loose pressure first to regulator shut off injector. A bad relay will shut it all down, also a bad regulator will do the same, also a short to one or more injector's
 

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Now I don't know how well this translate's to dodge. Mine was more a gmc van with vortec V6 and multi port (spyder) injection.
 

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Discussion Starter · #12 ·
iam going to try switch around the relays and see if that works, and test the relays after just to see if there working, does anyone know if a relay can work some and sometimes not,
 

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Yes a relay can work like that. They become old short out when hot. Remember there a form of a switch and a capasitor to boost power.
 

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Discussion Starter · #14 ·
hi i tryed a test to day on the fuel pump, and this is what i did, at the test port on the fuel rail i pushed the check valve in and released the fuel pressure in the system, and kept the check valve open and got some one to turn the key just to the on postion, and had a lot of pressure but after about 5sec. it just stoped no more pressure, my idea of how it should work would be [and correct me if iam wronge] that untill the the fuel system builds up to the correct fuel pressure that the fuel pump would keep pumping out fuel, and i also found that if i try to start it, it will run but now for only 3sec. and die, now if i try to restart with out going to the off postion on the key switch it doesnt even try to start, but if i turn it to the off postion then turn it to on postion wait 1sec. and then start it will run for about 3sec., if some know if this is how the fuel pump should work please let me know thanks or if any ideas any comments are welcome.
 

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I'm going to give my input here, though it won't be complete. Yup, your engine management computer , when the key is taken to 'start', turns the pump on for a coupla seconds to preload the injection system for starting. If you fail to take the key back to 'off', then you won't get the preload run from the pump. Same thing, if you hold the motor mashed when attempting to start, this is called 'clear out mode' in some books, and aids in starting a flooded engine, by shutting the fuel off. Now, I'm not certain, but I think you may have something catywompus in the engine management computer, or ASD, if you are not getting power to the fuel pump once the engine fires, but you are getting preload. However, if you do not actually know PSI, in the line, it may not be enough to maintain proper engine operation. I suspect a bad connection at the ECU. I would, 1st, turn the key on, pull the neg battery wire, turn the key off, and reconnect the battery cable. this will or at least should, reboot the ECU, amongst other things, I'm sure. If that doesn't give joy, I would pull the plugs, carefully, on the ECU, and look for corrosion on the pins, and recievers. My 2 cents, as it's where I would go with this, for starters...
 

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Discussion Starter · #16 ·
oh no please not the pcm, iam going to buy another fuel pressure guage tester tomorrow, and see if the fuel pressure drops when the motor starts up, i do know i hooked up my other fuel pressure guage on it and turned the key to on and got a reading of 45psi, but i havent gotten a reading on it when its been running because it cut off to soon now, it did run great for a little over an hour, now 3-5sec., but i get someone to start the motor and i will watch the guage to see if it drops psi, and iam most of all going to try to reset the ecu.
 
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