2.3L ('83-'97) Almost no acceleration

[jeffrohotrod]

I recently got a 95 ranger 2.3 5 speed. The previous owner cut off the cat and welded in a pipe. He replaced the o2 sensors plugs & wires throttle position sensor fuel pump & filter. He said he tested the compression and timing was good so it had to be fuel injectors. I have replaced fuel injectors & pressure regulator. Mass air flow sensor. Idle air control valve. Crankshaft position sensor. Ignition coils. It starts right up but when trying to accelerate it barely does anything. Sometimes it won't even go up a slight incline. I hooked a smoke machine up and could not find any vacuum leaks. Could anyone point me in the right direction cause I'm running out of ideas.

 

[Brain75]

any codes?
sounds like limp mode to me (even the OBD1's do that if you remove the O2 sensors)... with an OBD2 system I would get a vlink v-gate cable and forscan (free program to run on laptop and do more detailed diagnostic).

I'm not 100% certain on the 4 bangers, but I think your huge issue is the missing CAT. The computer takes O2 sensor data from before and AFTER the cat, right (don't know for sure on the 4 bangers)... with it getting the same upstream and downstream numbers it freaks out and just locks up into limp mode... first result on google was a guy who hollowed out his cat and now can't get it out of limp mode.

 

[Brain75]

with no load on it, after it is warmed up, try to rev up to 3k rpm... if it acts like it just can't go over 2500 rpm (roughly ford gauges are not that accurate) then I pretty much guarantee that is limp mode.

 

[scotts90ranger]

I don't think there's any real limp mode, at least for that, and that's not how the post O2 sensor is used... all of the fuel trim stuff is done with the front sensor, rear is just making sure the cat is working and if then it just throws a code.

I would double check the timing marks, there's a plug on the front of the timing cover to check where the auxiliary pulley is lined up, I don't remember which is what but there's a diamond and triangle mark on both pulleys and one is for each but the inner timing cover is marked with a matching shape at the alignment points. They way it's running I think the cam sensor (ran off the aux pulley, lower one) might be off a tooth, they really don't like that. Also double check both coil packs to make sure they're hooked up right. One side of the coil is for #1 and #4 and the other side for #2 and #3, you can mix up 1 and 4 or 2 and 3 but not side to side.

 

[jeffrohotrod]

There is no codes. Most of the time it will not even Rev past 2k rpms. I've checked the firing order and it is correct. I was wondering about cam sensor since that's pretty much the only sensor that hasn't been replaced lol. I took the inspection plug off but could not see any marks. When I get off work tonight I'll take the timing cover off and see what I can see.

 

[Brain75]

Do you have an expensive code reader (or forscan) or just the typical $35 hand held unit that shows (OBD2) P codes and emissions "ready" status? If not, and not interested in getting the $30 v-gate cable, I'd go to the nearest auto parts store and have them read the PCM codes (something the cheaper code readers can't do)... I bet it will show you something like "no input from xyz sensor" - when the computer has nothing at all coming from a sensor (like the wire is cut, disconnected or removed) it assumes the last known good value and limps along, often without reporting a P-code.
Something you might have caused by replacing a whole mess of stuff (throwing parts at it) is put a bad new part on it... New part quality is just absolutely crap right now, either it is limping because of the no cat or because one of your new sensors is a dud (2 most likely) of course the other possibles are wiring issue etc etc...

 

[Brain75]

another fairly likely thing I just thought of is PCM issues - specifically bad capacitors in the computer, over on ford-trucks and the mustangforum there are folks reporting a few bad caps even in an EEC IV (the computer up to 94, OBD1 - previous to yours) will activate what is essentially limp mode in those (there was no true limp mode back then in EEC IV but it is what I described, the computer assumes last good value and then limits the power curve).

 

[scotts90ranger]

There is no codes. Most of the time it will not even Rev past 2k rpms. I've checked the firing order and it is correct. I was wondering about cam sensor since that's pretty much the only sensor that hasn't been replaced lol. I took the inspection plug off but could not see any marks. When I get off work tonight I'll take the timing cover off and see what I can see.

I left off before but to see the timing marks when that cap is off you have to be on TDC with the crankshaft, if you have the crank lined up it might take another revolution of the crank to get the cam marks lined up.