Engine stumbles at city speeds - Ranger-Forums - The Ultimate Ford Ranger Resource


General Ford Ranger Discussion General discussion of the Ford Ranger that does not fit in any other sub-forum.

Reply
 
LinkBack Thread Tools Search this Thread
  #1  
Old 11-05-2014
Member
Thread Starter
 
Join Date: Oct 2013
Location: Fremont, CA
Posts: 8
Engine stumbles at city speeds

OK, '94 2.3l 5 speed stick, no AC with California emissions. So I have this glitchy problem. It only happens after the truck heats up and after a restart. I'm rolling along at about 40 and it's like someone takes ahold of the ignition circuit and flips it on and off about 10 times fast. If I roll up to a stop the engine holds at about 3500 RPMs untill I come to a complete halt, then drops to idle. usually there is a CEL light too. I've replaced everything, I mean EVERYTHING except the ECU. And yes, the ICM is well grounded. HHHEEEEEEELLLP!
Reply With Quote
  #2  
Old 11-06-2014
06FordFX4's Avatar
Member
iTrader: (1)
 
Join Date: Feb 2012
Location: Canada
Posts: 694
Did you check the code.....?
Reply With Quote
  #3  
Old 11-07-2014
Member
Thread Starter
 
Join Date: Oct 2013
Location: Fremont, CA
Posts: 8
yes, 121 122 224 remeber this is EEC-IV not ODB
Reply With Quote
  #4  
Old 11-08-2014
RF Veteran
iTrader: (1)
 
Join Date: Jan 2014
Location: Vancouver, BC
Posts: 7,615
EEC--IV is OBD 1, EEC-V(1996 and up) is OBD 2

Codes 121 and 122 both say TPS(throttle position sensor) is having a problem or it's wiring is.
TPS is easy to test with OHM meter and then with Volt meter to see if wiring or sensor is the problem.
If both test fine then Computer is the problem.
Google: test ford TPS

TPS sensor is the same on a 2.3l or 5.0l, it is just a variable resistor, like a volume control or light dimmer

224 is an ICM(ignition control module) fault
Easy to test these as well, many auto parts stores have testers and will test these free of charge.

New parts do not mean "working parts", just FYI, welcome to mass produced cheap parts, lol
This is why it is better to test a part first, confirm it is bad, before replacing with un-tested part, because that is what "new" means now
New = never been tested
We demand cheaper parts, so we are given cheaper parts, they slap a warranty on it and YOU are now the Quality Control department, they happily replace a defective part under warranty but it is a real PITA when you expect it to be working, so you chase your tail for a few hours and then discovery the "new" part is bad, lol.

Last edited by RonD; 11-08-2014 at 05:45 PM.
Reply With Quote
  #5  
Old 11-10-2014
Member
Thread Starter
 
Join Date: Oct 2013
Location: Fremont, CA
Posts: 8
OK, further observations. I found that my ICM faults out only after heating up and only after a restart. SOOOO if I go out and do the at home ICM test bright and early after an overnight sit, it will test fine. But I noticed that the right bank of the primary coil craps out after warm up and after restart. As an experiment I tried something. I loosened the ICM screws, slipped two hardwood shims under the ICM to create and airspace. I also have a ground wire running from the ground screw to the engine. After a long hot drive the coil is still firing on all cylinders. I realize this is a quick fix for a failing ICM, but it is an interesting experiment eh?

YES I agree with your new parts analogy. and it is indeed exactly my experience with a CKP sensor and a DPFE and an aftermarket ICM (the dying one i have now is a motorcraft one from a wreck) and possibly the TPS that I have now, and a shift position sensor on the Volvo..... come to think of it just about EVERY cut rate piece of **** I buy is exactly that! sigh! live and learn.
Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
'94 2.3l stumbles at city speeds iank1 SOHC - 2.3L & 2.5L Lima Engines 0 11-07-2014 07:28 PM
2004 2.3L, jerky and stumbles on acceleration Jbrando03 DOHC - 2.3L Duratec / Mazda L Engines 2 11-12-2011 10:19 PM
1998 4.0 stumbles under load jakjkl 4.0L OHV & SOHC V6 Tech 11 05-20-2010 12:07 AM
stumbles when defrost on racemx904 General Technical & Electrical 7 09-07-2009 11:57 AM
2.3 stumbles from 2500 to 3500 racemx904 General Technical & Electrical 4 08-08-2009 07:35 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -6. The time now is 05:20 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.