i have a 98 ford ranger 2.5 and ive read a thousand posts and yet i still cant fix my problem. every time im driving and i do a quick speed up ( my rpms go over 3 or 4k ) and i let off the gas the engine shutters andd dies or stalls. even in neutral if i rev it up and let off the gas it dies. runs just fine cold or hot in idle and when i drive like a canadian it also runs fine but its inconvienant because i cant drive into fast flowing traffic plus im sure its bad for my truck. also i have the code p1404 but im not sure that has anything to do with it seeing as i've already read tons of post about it. i should also mention i have thought that it could maybe be the code or egr or the aig or whatever its called that helps with air flow. please someone help me im screwed right now

 

45 views on this post and already so many responses. im open for any tips or advice. like real advise beacuse in a few hours i will be taking my truck to a mechanic shop but if someone can save me hundreds of dollars that would be awesome

 

Check the IAC as it controls whether the engine is cut off from air completely when the throttle plate is closed. If you get a fast idle immediately after you start a cold engine, the IAC is likely working. If you have a MAF problem, the computer could think there is little to no air, and would cause hesitation by cutting the fuel flow to match.
Check your fuel flow and pressure. Most gauges have a valve you can open to catch the flow when the pump is energized. If the pressure is good, check the volume by measuring flow over a 10-20 second time period, and multiply correctly to determine if that is the proper gpm rate.
If the problem is that whenever you abruptly close the throttle, the engine dies, then check the above stuff. Other wise, please add more detail about the symptoms.
tom

 

thank you tom. ive checked pressure of the valves or whatever sorry not 100 percent mechanic savy but im im good at taking apart thingy ma bob A and B just dont know names. im not sure what a maf is so please explain that part. so far what i have done this morning is i have taken off the egr, the dpfe and the iac and clean the hell out of each. but when i put back on i still have the p1401 code and the thing still shuts down whenever i rev up the engine and then suddenly let off the gas

 

o i have also checked fuel pressure and that was great as well

 

anybody know what would happen if my egr vacuum solenoid went bad??? maybe thats my problem

 

MAF is Mass Air Flow sensor. It is in the large tube between the air filter and the throttle plate & intake manifold. It has one or two wires that are heated by electricity flow, and will cool when air goes past. Knowing the ambient temperature and current applied, one can calculate the MASS of the air flowing into the engine. If flaky, it can cause hesitation and poor response. It can also cause P0170 and P0174 codes, I think.
Another thing to look at is the TPS. If it goes flaky, the computer can "think" that the throttle plate is closed when in actuality it is not, and thus decide to cut fuel flow. That can also cause transmission torque converter lockup to dis-engage and re-engage ***** nilly.
tom

 

ok update after cleaning everything out its not dieing when i let off the gas pedal however it is still bogging down alot. i talked to a semi mechanic he said that when it is bogging down he notices that itll start running great again once the vacumes caught pressure again or something like that. he said it sounds like something is just taking to long to open or close after each rev. PLEASE SOMEONE explain this to me

 

The MAF will cause bogging ... it will be slow to realize the air is passing by if it is dirty ... and will cause hesitation as the fuel flow will not catch up to the air flow that is already happening. Inside are two wires that can get schmutz on them, and they will report bad data to the computer. I took out the four torkx screws, {I think security torkx}, disassembled enough to see the wires and cleaned them using a q-tip. VERY GENTLY as you can mess them up if you are rough.
Did you check fuel VOLUME? Pressure is nice, but if there is a restriction in the filter, it will show pressure at low or no volume flow, but once you start to use fuel, such as while driving and accelerating.... it can't flow enough ... and the pressure would then drop and the engine run poorly. So, volume is significant. Easy to test with a gauge equipped with a 'tap' and small hose to gather the fuel.
tom