Engine hiccup under load

[Joe0816]

I want to start by saying thanks for any help, I'm on powerstroke.org and I am assuming yoi guys are just as helpful. I have a 93 2.3L manual and I'm having an issue. When accelerating, my truck misses to the point where i look like a 10 year old trying to drive a manual for the first time. It will start lower in the gear, through mid but at high rpms it goes away. On the highway it pulls fine. The plugs were replaced a year ago, I pulled one out and it looked fine, gap was right. I just replaced all wires from the KEMs that were on it. I ran a few bottles of sea foam through brake booster line, one through throttle body, and half a can of cleaner through throttle body. I hooked up a timing light over the wires, and saw that one plug was barely going off, another on the same coil having similar issue. Replaced the coil pack. Still having issues, and I can't afford to keep playing the guess what to replace. I tested the injectors, all of which tested fine resistance. Also, while idling, its fine and I can rev it fine. Please help!!!

 

[Joe0816]

I should add, it started out small then got to the point where its bad. As in like a teeter taughter down the road.

 

[Mark_88]

Sounds like fuel pressure...pull the line on the FPR and smell for gas...if you smell gas then there is a problem...could also be sporadic fuel pump issue or even the infamous inertia switch...

My Tempo would bunny hop down the road in lower gears but once it got going it was OK...but would sporadically die on the highway...and this was a combination of fuel tank pump and, in a separate issue, the inertia switch fried but was still working and would cut out if I hit a small bump...

Did you try checking for codes?

 

[Joe0816]

Where is the fpr? Is the pump on the frame rail? A way to test it? Where would the obdII port be? Where is the intertia switch and how to tell if it is fried? New to rangers, used to 7.3Ls. Thanks alot

 

[Mark_88]

The FPR is on the fuel rail...it has a vacuum line attached to it...just a small roundish thing.

The fuel pump is probably on the frame rail just under your feet when driving...close to the fuel filter...which may need changing as that can cause similar issues if you haven't changed it...

Your truck is OBD-I and there should be a connector under the hood...not sure what side...OBD-II have connectors just under the steering wheel inside the cab.

The inertia switch is under the dash on the passenger side up near the firewall...should be a reset button on it but I wouldn't advise to push it too often...you can by-pass it by using a U shaped wire (10 or 12 gauge I believe) pushed into the connector to test...if it stops bunny hopping then the switch is fried internally...the one on my Tempo was physically fried with melted plastic but still managed to function...somewhat.

 

[Joe0816]

Fpr: I thought that was what it was but didn't want to sound stupid I smelled it no gas. the fuel filter looks pretty new which the guy said he replaced. Does obd I cheap scanners at oreillys need a CEL on for it to work. I'll check the switch, does all fords have it there? My 97 f250 had it in the same spot.

The FPR is on the fuel rail...it has a vacuum line attached to it...just a small roundish thing.

The fuel pump is probably on the frame rail just under your feet when driving...close to the fuel filter...which may need changing as that can cause similar issues if you haven't changed it...

Your truck is OBD-I and there should be a connector under the hood...not sure what side...OBD-II have connectors just under the steering wheel inside the cab.

The inertia switch is under the dash on the passenger side up near the firewall...should be a reset button on it but I wouldn't advise to push it too often...you can by-pass it by using a U shaped wire (10 or 12 gauge I believe) pushed into the connector to test...if it stops bunny hopping then the switch is fried internally...the one on my Tempo was physically fried with melted plastic but still managed to function...somewhat.

 

[Mark_88]

The codes can be checked at any time.

Does the CEL light up when you turn your ignition to the on position? It should light up...if not...the bulb may be out...

I don't think there is an actual code for fuel flow issues...but you might want to check the codes in the Tech Articles on the main page...my Tempo never gave me a CEL at all over 14 years and 400,000 km...but my EGR failed an e-test due to a wonky EGR module.

 

[Joe0816]

The egr system was replaced very recently, that and the fpr are the only shiny things under the hood lol. The intertia switch is not on passenger side under dash. Cel light works, but not on.

 

[Mark_88]

Not sure where it would be then...did you pull back the carpet near the top? It may be hidden under the carpet...haven't checked my 96 for one and my 88 doesn't have one for sure because it is carbed...the Tempo had one in the trunk.

Here is the link from the Tech articles on how to test for codes...if the light is not on you may get some stored codes...

http://www.therangerstation.com/tech_library/OBD_I.html

 

[Joe0816]

Yup, checked all in that area. My buddy has a 94 ranger I'm gonna swap out our map sensors tonight to see if thats it.

 

[Joe0816]

I meant maf sensor. I swapped ours out still did it. i check tps and it will read up to 3.2V but after that it quits. I'll replace it tomorrow. Do you have to pull the throttle body off or just the egr?

 

[Mark_88]

Just the EGR is accessible...from what I remember...last one I took off from a FI engine was from a 87 Mustang...and it was kind of a reach but still manageable...

I would check up under the dash near the center hump for the inertia switch...it isn't very big...

I just checked the on-line manual for the location of the inertia switch but couldn't find a diagram...it does list the inertia switch in the wiring diagram though so you do have one...

http://www.therangerstation.com/forums/showthread.php?t=319

Also check Youtube for videos...someone has probably posted a fix..,

 

[Joe0816]

Well I replaced the tps and its still doing it. Taking it to Ford on monday.

 

[Mark_88]

Well...I hope they find the problem without too much expense...last time I was in a dealership they charged me $120 to diagnose my truck...the mechanic spent two hours looking at the carb...I think that's all she did because she didn't actually fix anything or give me a workable solution...then they showed me an estimate for fixing it...$2,000...

I figured I could replace the engine, take a trip south for two weeks, buy a few cases of beer, and still have enough left over for something else that I probably need more than giving them more money...

But they did give me the drive clean pass...

 

[Joe0816]

Well my old man works at Ford, body shop manager, and because of that, I get the discount at Ford. They usually don't charge me for diagnosing, but ya never know.