[FIXED] 2001 Ram won't start unless you give it a drink

Great following along with you guys! Can anyone hazard a guess as to why the truck starts and runs when fuel is added to the TB?

will do, i will get the computer on monday or tuesday, I hope I can get the connector cleaned up to work.

RobBrown wrote: Great following along with you guys! Can anyone hazard a guess as to why the truck starts and runs when fuel is added to the TB?

Thanks! As for the fuel, it's all about the lack of injection pulse. Personally, I've been trying to connect this alternator/ASD circuit to the injection pulse the ENTIRE time. My guess is that there's even more going on inside the PCM than we're aware of. None of the service information connected the ASD pin to the alternator power feed, so it's possible that the injector control circuits are somehow tied in, as well.

Right...and he says that once it gets started, it keeps running on its own. Which is weird. What input to the computer would suddenly engage the injector circuits? Maybe cam/crank sensor? Like if the engine reaches a certain threshold rpm (from the fuel being manually added and the engine actually starting) the computer kicks on the injector circuits that had been inactive during a normal crank attempt? Just trying to imagine what would change when fuel was added that would kick on those injectors.

Obviously all a guess. But super interesting!

Ok , Ws2664 back with an update about my 2001 dodge ram that was a no start and not charging that i posted last thursday, as you all might remember I had no injector pulse in the crank position but when I sprayed the throttle body it started then when i released the key to the run position my injector pulse came back and the truck ran on it's own. I hooked my scope to the cam sensor signal and had my 5 volt square wave and hooked a spark tester inline and had spark but no injector pulse. The customer said this happened the same time the alt. quit. He took the alt. to 2 parts stores for testing and they said it was good so I checked the two wires on the back of the alt. and I had no power on the blue and no computer control on the green wire so I unplugged the computer and found a burned plug and a broken pin. Got the new computer today and I got my injector pulse back so the truck starts on it's own, i got my power back on the blue wire so now the alt. is charging, however it's not charging great and I still don't have computer control on the green wire. We told the customer and he went with a new alt.and as Scanner Danner would say " IT'S A FIX" I got good charging voltage and I got my square wave and duty cycle back on my green control wire. Don't understand why that would happen unless the charging voltage was low enough from the old alt. the computer didn't need to control it. Any way that's my story and i'm sticking to it. Thanks.

Alright! Thanks for posting the fix to this issue.

RobBrown wrote: Right...and he says that once it gets started, it keeps running on its own. Which is weird.

as you all might remember I had no injector pulse in the crank position but when I sprayed the throttle body it started then when i released the key to the run position my injector pulse came back and the truck ran on it's own.

Really? :huh: I must have missed that in the opening post. I thought trat50 meant that he could get the engine TO run by adding fuel, not that it kept running. I'm glad you guys pointed that out, but this just makes it even weirder!

Very glad to hear about the fix, ws2664! I'm interested to know what kind of voltage you had on both the alternator field wires when it wasn't charging well? I suspect the PCM was full fielding the alternator and not getting the charging voltage it wanted to see.

Hey tyler, a quick note to your question ,with the new computer i had battery voltage to the alt, as you might recall that blue wire was on the same plug that burned up so it wasn't turning the alt. on at that time. the alt did turn on and start charging but poorly, it was 13.5 with no load, it went down to 13.1 with the A/C on then it went down to 12.7 when i turned on the headlights, I had my Snap on Modis on the green wire set to duty cycle and it was 0% and DC voltage showed no square wave. I set this up on my own truck as a comparison, Which is a 99 Dodge 4x4 with a 5.9 and I had a 35% duty cycle and a battery voltage square wave at idle with no load so I did think that was strange not haveing some kind of duty cycle with the old alt.I think a full field would be 100% duty cycle but this was 0%. My first thought was my new computer might be bad because normaley chrysler runs about 35%-45% duty cycle at idle no loads and as high as say 65%-70% with loads on. We went with the new alt. just to get the voltage up and low and behold my duty cycle and square wave came back. at idle with the A;C on duty cycle was 49%. Like I said, I'm not going to swear to it but I'm pretty sure full field should be 100% duty cycle and I tryed full fielding the old alt and it didn't change at all now I could be wrong about the 100% I never really paid attention to that, I know what the range should be and I never really saw a 0% duty cycle before so that kind of thru me a little bit. I hope this helped

Yes, that is correct. If I gave the throttle body about 1/2 cup of gasoline the truck started. The first time it started I told my daughters' boyfriend that this thing will be running out of gas in 10 seconds. Ten minutes later it was still running. I told him to take it around the block.. he took it around the block 7 times. He did a few burn outs and complained that it didn't have first gear. He pulled it back into the yard and shut it off. Again no start.. until I primed the throttle body. Ran normally again.

I'm planning on picking up a computer connector this Friday. (Last weekend was too busy). I'll post our results when we get a good computer and alternator.

My guess on why it would run and stay running is it is voltage related. Using an external fuel source got the truck running and provided a higher system voltage. With the burnt pins, system voltage on those circuits were probably low, combined with low voltage during cranking was enough to keep it from starting. Make sense?

trat50 wrote: Yes, that is correct. If I gave the throttle body about 1/2 cup of gasoline the truck started. The first time it started I told my daughters' boyfriend that this thing will be running out of gas in 10 seconds. Ten minutes later it was still running. I told him to take it around the block.. he took it around the block 7 times. He did a few burn outs and complained that it didn't have first gear. He pulled it back into the yard and shut it off. Again no start.. until I primed the throttle body. Ran normally again.

I'm planning on picking up a computer connector this Friday. (Last weekend was too busy). I'll post our results when we get a good computer and alternator.

Right on, my mistake sir, I didn't catch that initially. Thanks for keeping us updated! Based on ws2664's results, I'm even more confident we're on the right track with this repair.

ScannerDanner wrote: My guess on why it would run and stay running is it is voltage related. Using an external fuel source got the truck running and provided a higher system voltage. With the burnt pins, system voltage on those circuits were probably low, combined with low voltage during cranking was enough to keep it from starting. Make sense?

Oh, cool. Good idea.

Sorry, this took too long - but the owner of this truck did not have the money to finish this repair until this week.

(1.) I replaced computer connector with burned pin hole with connector & pigtail from junk yard Dodge Ram.
(2.) Owner replaced the Dodge Ram PCM with a PCM from the same junkyard Dodge Ram.
(3.) Owner replaced the alternator with a remanufactured alternator from a local auto parts store.

The owner (my daughters' boyfriend) cranked Dodge Ram - it fired and stayed running. (No priming of the throttle body was needed). Owner test drove Dodge Ram - reporting it was running just fine, and he now has 1st gear. (1st gear was lost when PMC broke).

NOTE 1: This junkyard computer has not been flashed with the VIN for this truck. He is saving cash up to have the dealership do that. Thanks for all the help - this truck is now back on the road, running and starting as expected.

NOTE 2: Odometer has "no bus" message and Overdrive is not working. Everything else works fine. The owner is not concerned with no bus message. Hoping VIN flash will fix these 2 things.

Dude, really awesome of you to get back to us after so long! Great to hear about the fix. We really appreciate hearing back on repair threads like this.

I'm kinda surprised the engine cranked and ran? :lol: Not because I doubted the fix, just because of the VIN mismatch. This truck may be pre-SKIM, not sure.

The 'NO BUS' thing will probably get fixed with the reprogram, but I'm not sure about the overdrive. Let us know if this doesn't get resolved, and we can dig into that.

OK, will do Tyler. Thanks again.