89 Intermittent power loss pleases help

67coupestang

Founding Member
May 31, 2002
499
0
17
38
Visit site
ok its actually in my ranger but i seem to have the ranger station stumped...
so heres the skinny ive had this ranger for about a year. got it cheap cause it didnt run, no biggie all it needed was a fuel pump, did that, cleaned out the tank, new filter, FPR etc. okay so fuel delivery shouldnt be a problem. but id say 90% of the time it just has no power, like its pulling a trailer, or plowing through deep water, it takes off fine, but then hits a "wall" and you can feel it pulling back. no matter how hard or lightly i hit the pedal it just bogs. then at about 2000-2500 rpms (and sometimes its hard to tell because my tach also only works 50% of the time) its like a switch is flipped and the truck pulls just fine, seriously the change in power is that sudden and dramatic. So after pulling off a stop light and finally chugging up to speed with a line of cars behind me, i leave it in gear (5-speed manual) i blip the key off and on and at the next light its fine, power all the way through. I dont know where to even start testing... timing marks seem to line up for the cam, FPR holds vacuum, MAP seems to be working (runs worse with the vacuum disconected), vacuum is fairly steady bounces between 15-18 inches. I'm lead to belive it could be the ignition module (especially with the tach problem). I'm really leaning towards electrical because of the fact it can "reset" it by blipping the key. the check engine light comes on after about 10 miles IF the 10 mile mark is city driving, i can hit the highway forever without the CEL coming on but in the city it comes on, then after enough hwy driving it will go off. it will also go off when i bip the key... im lost REALLY lost and the afformentioned line of cars is getting old.. please please help me before i go crazy ... anything, any ideas no matter how far out im willing to try TIA!!!:flag:
 
  • Sponsors(?)


Dan P.

Founding Member
Apr 26, 2002
482
0
27
N.C.
stangnet.cardomain.com
"I'm lead to believe it could be the ignition module"

You hit the nail on the head there buddy. Had the same problem on my 92, replace it and be sure to use some dielectric grease on the back of the module. Its located on the lower intake manifold.
 

67coupestang

Founding Member
May 31, 2002
499
0
17
38
Visit site
Thank you! nobody could lead me in any direction at the ranger station... I'll see if i can pick one up tonight, or at least get one ordered, ill post results as soon as i find out. thanks a TON!
 

67coupestang

Founding Member
May 31, 2002
499
0
17
38
Visit site
wel... that wasnt it. Tach works though :) for the first 3 miles of the test drive after swapping modules, it was fine, then about a block from home it acted up again.. i dont know where else to look and its getting steadily worse. last night it was actually bucking like it was stalling out going down the road in 2nd. however eariler in the afternoon i was driving around to a couple of jobsites in town and i just left it running the whole time instead of shutting it off so the CEL was on and i didnt notice any power loss... so whatever is tripping the CEL is being "switched off" or bypassed by the computer and whatever that is maybe causing the problem. does that sound right? next time the CEL is on i'll have to try to catch it and run the codes...
 

67coupestang

Founding Member
May 31, 2002
499
0
17
38
Visit site
so i ran the codes with my handy little actron

KOEO
34 egr valve position
41 EGO always lean

KOER
21 engine coolant temp not at normal op temp OR edis fault CPS circut
42 EGO always rich... wait... what? but before you said...
33 EGR valve position not opening or not seated
77 operator error during during dynamic response
52 power steering circuit open or no changes...


so which way do i go now... obviously the egr's high on the list. clean it? coolant temp could be cause its sat for a while now before i ran the test... o2 sensor i dont even know whats up with that 77 and 52 dont really worry me but what about 21 edis fault in the cps circuit, how do i check the crank position sensor... where is it located on the 2.3 i know someone will say "you need a shop manual" and i agree if i could find a chiltons i would get one but all i've seen are haynes, and not only are they not helpful, but more often than not ive found them to be innacurate, especially in electrical testing specs...
 

67coupestang

Founding Member
May 31, 2002
499
0
17
38
Visit site
okay im omitting the egr valve. i pulled off the sensor portion and grabbed the plunger with a set of pliers and it moved quite freely. there is little to no vacuum at the green plastic vacuum line attached. the red going to the switch on the passenger side inner fender has a steady 17 but the output was barely enough to move the needle. im not sure under what circumstances that valve opens... also when i hooked green to red and just bypassed that switch/valve the engine ran like s*it. not just at idle but i kicked it up to about 2k and there was a definate miss like 2 cylinders just dropped off.
 

Dan P.

Founding Member
Apr 26, 2002
482
0
27
N.C.
stangnet.cardomain.com
Does the CEL come on when you go up to 45mph or the engine is warm? I would try to replace the EGR and see what happens. But I would also check the ICM again. I have seen guys go through 2 or 3 before they got a "good one" . Did you put any grease on the back of it ?
 

67coupestang

Founding Member
May 31, 2002
499
0
17
38
Visit site
the CEL only comes on after its warmed up IF im driving in town (stop and go under 55) otherwise i have driven 2hrs on the highway and it never came on until i hit a town, and do enough highway driving after that it will shut off again...

I dont know what to do... it was a little clearer yesterday and it wasnt raining or as humid and what im reading here and at the rangerstation makes me lean towards the egr. i swapped the sensor out with one i had laying around (from a 5.0, i dunno looked the same) havent road tested it but its still throwing the egr code...

if i have any energy after work tonight im gonna pull the intake /egr and give them a good cleaning
 

72COMETGT

New Member
Feb 1, 2009
8
0
0
With the type of problems that you are having I would take a look at the ECM. Sometimes when you get conflicting engine codes and/or symptoms like you describe when driving. These could be computer related issues. Something inside could have become loose or a bit corroded. What ever it is the ECM just doesn't work right. Try to get your hands on (borrow from a friend) another ECM to try in your Ranger to see if that's the problem. If not you take the ECM out you can get it checked at places like Carquest. They have to send it out to get it checked. It costs around $100 and a weeks time. Maybe in the States it's less money & quicker but in Canada it's around $100 and a week. You guys are spoiled!