Hey i have a 94 ford ranger 4.0l at, 4x4 xlt. has 141k on it. and recently, i have been having some problems with it. what the problems are, my check engine light keeps coming on randomly when i accelerate up to 2500 rpms and hold it. also, if i lay my foot into it, it downshifts into 2nd, and use to actually get up and go, recently, its been a turd, and when it hits about 4000 rpms, it starts to cut out kind of like a rev limiter, but sounds like crap! And i know its not the rev limiter.. cause it redlines at 5k. and doesn't have a 2 step sounding revvy. just holds at 5k without bouncing. and anyways, it cuts out, and it wont go anyfaster! But the weird thing too is that if i let off of the throttle a bit, it goes faster! But shifts into 3rd. if i keep my foot into it. it will hold at about 67mph, and at like 4200 rpms. after that, it cuts out. but if i let off while in 2nd (or first) it will actually hit 5k. which is totally weird. also, it hesitates when i go to take off. like i will just feather the throttle, and its like im not even giving it gas! it just sits there. today, i was leaving work with a buddy of mine showing him what it was doing. i had it to the floor and it was riding at about 1100 rpms and cutting out and missing. its weird. the only thing that came to mind was that i just put a cold air intake on it. but i still have my o2 censor hooked up and everything. but today, i looked at it, and my altinator pully had chewed a hole in the intake system. and i thought that was the problem. NOPE. replaced it.. still did the same thing. so idk what is going on! please someone help!!

 

Welcome to FTE.

Your not being kind to your engine, operating it the way you've posted.

You had an OEM cold air induction set up properly sized for the engine, so no need to have moded it, as the stock set up isn't flow restricted nor is the engine wimpy.

When you did mod it, was the AIT sensor included in the new setup???? How long was it run with the hole in the air tube????

Are you using an oiled foam, or cotton gauze air filter in the intake mod????

Where are you on All past & present due scheduled maintenance items, like air & fuel filters, pcv valve, plugs & wires & what brands are you using???? Yes the 4.0L is sorta persnickety about what we use.

How many other mods have you made???? There are so many unknowns, we need some kind of baseline to know where to help you begin a trouble shoot.

 

Actually, im not rough on my engine at all. the only mods that are done to it is a full spectre cold air set up with a filter, and the o2 censor still hooked up. and a cherry bomb exhaust (i don't reccomend it to anyone...sounds like crap). getting ready to chop that off and put a flowmaster. but no, i don't thrash on it at all. turns out, i found the problem.. my altinator pully had chewed a hole into my intake system at the bottom of it... and when i was going slow, my o2 censor must have been reading wrong (obvioulsy) and it was getting too much air, therefore, causing it to cut out, and then when you would get on it... it wasn't getting enough air.. so i replaced the part. and it runs fine! Now i just have to fix a weird howl that its making when its running! it doesn't sound like a fan belt squeak, but a howling. its weird... any ideas what it might be?

 

Is the howling noise coming from the front of the engine & did it begin After the alternator pully did its thing on the intake air tube??? If so, look to a problem with the serp belt, idler or tensioner pully bearing, or the tensioner itself, like a weak or broken tension spring thats not applying proper belt tension. There are molded in tension range marks on the tensioner casting. If all that checks out, maybe put the water pump & alternator bearing on your suspect list.

 

Alright. Ill be sure to check that out right away! Thanks alot for your help!