So the 3.9L '97 that I have died on me this morning on the way to school. I was sitting at a stoplight, then the truck just shut off. (No coughing, no rpm adjustment, just died). When I tried to turn it back over, the starter was cranking, but nothing past that. With the help of a few kind individuals, we got her pushed up and out of traffic.

I spent the better part of the morning going over quick fixes in my head, but to no prevail, here were my actions:

-Quick inspection of visible wires/connections
-New Cap and Rotor
-Inspection of vacuum lines

After I installed the new cap and rotor, the pickup started again, but quickly died. When I tried to fire it again, I could get it running with my foot on the throttle but it would not idle. (Also, when it initially starts, it sounds like there is a knock of some kind coming from the engine, and I can smell that it is definitely running rich, at least at this point). So my plan was to just drive two footed and get it to a parking lot that wouldn't tow me, but after a put it in gear and let it sit for a while with the load on it, it ended up dying again even with my foot on the throttle.

And all the while this is going on, I feel that the pickup is somehow draining power, (it had to be jumped after the new cap and rotor, and was dead upon arriving at my house via tow truck).

I don't claim to be a mechanic, but like to think that im pretty good with my hands and pretty good at problem solving, but this just has me stumped. Does anyone have any suggestions on where to go next?

I also won't have time to get to it until Friday afternoon, this week has been crazy enough without this being thrown in there.

Thanks in advance!

Kyle

 

Check fuel pressure. It might be the fuel pump.

 

You didn't let us know how many miles on the truck. I have a 98, did the same thing. Went through all the normal procedures, tune up, checked all sensors, fuel pump which I did replace because my fuel gauge wasn't working right anyway. None of this stuff was the answer but elected to go forward since I wasn't getting rid of the thing till I solved the problem. Took months, no error codes except for the fuel level sensor. The stalling was getting worse. It would die after just starting it and it ran maybe 30 or 40 seconds. Frustrated, I decide to change out the PCM since the truck has well over 200K on it. Couldn't find one in the junkyard which led me to believe this must be a hot item....none at all to be had. Ordered online and asked if they had a run on these things. The guy told me yes all the way up to the year 2000. Anyway, solved my problem, no more mystery stalling. Please understand this was my last resort after doing much research and replacing many parts which the truck needed anyway if I was going to keep it. One thing, make sure the plugs on the computer are tight and see if it makes any difference at all. I was first using a cable tie to hold them in tight and it helped a little probably changing something internally however, it wasn't reliable as it would still stall, maybe not every day but it was still very unpredictable. Just a thought in case you do a lot in terms of solving your problem. Good Luck!

One other thing to check is the IAC since you couldn't idle it and had to keep your foot on the gas. Notorious of a bad "Idle Air Control" motor.

 

While I agree with Robertwav1 on the miles,mine was 132,000...I recommend looking into the fuel pump issue 1st as Dodgevity suggested,as it is an easy check before buying a PCM...just check to hear if pump engages when turn key to on before you actually crank it,have someone listen close to tank if you can't tell from listening from seat...had almost exactly same problem as you with my '97,5.2 just 2 weeks ago...pump would work sometime,sometimes not,and could not tell myself if pump was engaging,cause it would work for many days in a row,then not several times a day,or start/stop often...had to work both brakes,accel to keep it going,not very workable...thinking pump/or strainer was clogged(just bought truck a few weeks earlier, so was not sure how well previous owner kept tank clean)...was fuel pump so I dropped tank & replaced pump,no problems since...good luck.....fyi,if you do drop tank yourself,try NOT to bend straps,as they are exact fit...if u bend them,and don't realize it as I did,u probably will not b able to reach the bolts again...took me a while to figure why one side would not reach the bolt,had to straighten strap to reach...whitty.

 

First I would just like to thank everyone for getting back to me so quickly! You guys all have some great places to start, and I am thinking that I will start with troubleshooting the fuel pump. (Figured it could be the filter too, but isn't the filter integrated with the pump on these guys?).

Also, to answer the mileage question, Right now she is at 180K. I have service records of everything I have done to it, but unfortunately that only goes back about 20K miles. So there is basically 160K where I have no clue as to what has been done to it.

And Whitty, when your's was acting up, would it sometimes start, then die, then not be able to start for a while? Thinking back on yesterday, I really smelled gas when it was starting for the first time after sitting for a few hours, then once it wouldn't start I don't remember smelling any. This could be due to the fact that some gas could be seeping past the filter (if clogged) or through the pump correct? And if the fuel flow was interrupted, this would cause the dying and not starting correct?

Thanks again,

Kyle

 

I have a '97 Sport, as does my BIL coincidentally, both with the 3.9. His recently began dumping gas on the driveway the second he turned the key. His truck would start and run roughly, obviously starved for fuel. Other times not start at all.

He called a tow truck to pick it up and his fuel line had opened up. Nothing was wrong with his pump / filter.

Hope yours is that simple. Good luck.

 

Hi Kyle...yes,it would do EXACTLY that,went on for almost a week...could not smell excess gas,& could not figure why it would work sometimes for days as a time,then not work at all...btw,forgot to mention that it would crank,run a few seconds,then stop...over & over again,3x's,5x's or whatever...then I tried gunning it once it started to about 3,000 rpm to see if it would stay running,anything to KEEP it running,& that usually worked(often it took several starts before it would stay running because after running @ 3000 for several seconds it would die if I left it go to idle) until I got where I was going,stopped and tried to start it again after 10 minutes or whatever when I was done shopping ,etc...once it got running after that went on for almost a week,I thought it must be the pump or pressure regulator on top of pump because of the constant running/stopping...so since I could not really hear myself if the pump was engaging,I asked a friend to listen by tank to see if he could hear......sure enough,sometimes he could hear it,sometimes not...so I took a chance that it was the pump/regulator or maybe even the strainer was clogged...all the same since they are all one unit anyway...bought new Airtex(lifetime warranty) off ebay ($116)for half of what it cost at Advance...could not afford the Bosch's,or other alotta $'s....works fine now,2-3 weeks so far,no probs at all...my strainer was clean,so must have been motor on pump or regulator...hope this helps....ps,while mine is a '97,I have the 5.2 motor,and have been told by several mech's that mine does not have a inline fuel filter(cannot find 1),mine is JUST the strainer on pump(sucks,would prefer 1),so did not have fuel leak issue as u might have or the other guy(lambs) had,so yes to your question of fuel flow interruption...u MUST have about 45 psi (approx)to open up your fuel injection ports,if not will have similar probs w/starting/stopping if you smell alotta gas from any leakage...try to find leak if there is 1,and if your not sure since starting it u don't remember smelling any gas,try hearing the pump & also IF yours has a inline filter for it to leak,might not have 1....if u go the pump route,I can let u know where to go on ebay for the same pump u can get at Advance(they use Airtex too) or wherever to save $100 or so...btw,some pumps on ebay u can get for $70 or so,luckily found out before I bought 1 that they are interchangeable knock offs that work on whatever vehicle ...looking forward to hear what your prob was,good luck...Mark.

 

When my PCM died, the truck did the same thing, instantly died from no spark, then would cough and sputter and just wouldn't run.