eblau
Adventurer
I know a lot of you have E250/ E350 with 351W so heres one for you:
My van: 1992 351W 160,000 miles. Well maintained.
Classic bucking/ stuttering misfiring etc. issue but comes and goes like most of these do. The last round of this was way worse than usual though, in addition to the random misfire/ stutter there have been fits of backfiring and once so far it has shut off while idling. I have done KOEO test and the most recent codes were 123 and 113, 123 being the most relevant as it is TPS input voltage too high. 113 is a rich code which obviously could have been set at any point during this last fit it was throwing. I cleared those, drove it for about 30 miles then had another round of codes, after the shutting off while idling, 183 and 128. 183 being a rich code, again not going to get me anywhere BUT 128... MAP. I have replaced the TPS and even had to modify the eccentric holes in the TPS itself it get it below 1.0v at idle so I can "assume" its not that, although with the garbage being produced these days it certainly is suspect. I have removed the PCM and had the capacitors replaced as well as the board cleaned but mine was pretty bad so I cannot rule that out at this point. My brain is ruling out vacuum leaks because of one particular thing it does/ does not do: randomly it will increase idle from normal to up around 2000 then back down again. I have checked the notorious hard lines for cracks, the TAB and TAD lines look great and I have repaired the tank vent valve rubber lines. It will do that revving on its own and its very precise how it revs and drops, like something controlling that specifically unlike a vacuum leak where its either leaking or it isn't and erratic while the PCM tries to adjust. Occasionally it will run perfectly, we made a run down to TN where we enjoyed nearly 1000 trouble free miles in the summer with the AC cranking the entire time, it stuttered slightly when pulling a grade but otherwise it was fine. My intuition is telling me check the TPS, check the idle valve... if they are in spec I think I may have another issue with the PCM. The PCM sends its 5v reference to the TPS in addition to other various sensors on the same circuit like the MAP sensor so perhaps there is a short and its sending more than 5V to the TPS and MAP randomly? Any better ideas? I was planning on another 1000 mile long weekender in March but this has axed those plans.
My van: 1992 351W 160,000 miles. Well maintained.
Classic bucking/ stuttering misfiring etc. issue but comes and goes like most of these do. The last round of this was way worse than usual though, in addition to the random misfire/ stutter there have been fits of backfiring and once so far it has shut off while idling. I have done KOEO test and the most recent codes were 123 and 113, 123 being the most relevant as it is TPS input voltage too high. 113 is a rich code which obviously could have been set at any point during this last fit it was throwing. I cleared those, drove it for about 30 miles then had another round of codes, after the shutting off while idling, 183 and 128. 183 being a rich code, again not going to get me anywhere BUT 128... MAP. I have replaced the TPS and even had to modify the eccentric holes in the TPS itself it get it below 1.0v at idle so I can "assume" its not that, although with the garbage being produced these days it certainly is suspect. I have removed the PCM and had the capacitors replaced as well as the board cleaned but mine was pretty bad so I cannot rule that out at this point. My brain is ruling out vacuum leaks because of one particular thing it does/ does not do: randomly it will increase idle from normal to up around 2000 then back down again. I have checked the notorious hard lines for cracks, the TAB and TAD lines look great and I have repaired the tank vent valve rubber lines. It will do that revving on its own and its very precise how it revs and drops, like something controlling that specifically unlike a vacuum leak where its either leaking or it isn't and erratic while the PCM tries to adjust. Occasionally it will run perfectly, we made a run down to TN where we enjoyed nearly 1000 trouble free miles in the summer with the AC cranking the entire time, it stuttered slightly when pulling a grade but otherwise it was fine. My intuition is telling me check the TPS, check the idle valve... if they are in spec I think I may have another issue with the PCM. The PCM sends its 5v reference to the TPS in addition to other various sensors on the same circuit like the MAP sensor so perhaps there is a short and its sending more than 5V to the TPS and MAP randomly? Any better ideas? I was planning on another 1000 mile long weekender in March but this has axed those plans.
