Big Mystery "Limp Mode" – Check Engine and Power Loss on 1995 F250 460 EFI
 

Hello Ford experts! I’m new to your forum and would love to tap into this great resource. I’ve been scouring the forums looking for answers to help narrow down my issue and have found several posts similar to my issue but not much that points to a definitive answer. I’m thinking that this is because of Power Loss is due to the Fuel Injection system “shutting” down according to the Haynes Manual to protect the truck from further damage.

Description of the Problem:
- Check Engine light is on.
- The truck runs very poorly.
- It isn’t drivable really due to the power loss.
- The issue is somewhat intermittent. It will happen 3 of 5 times and just recently started.
- When this happens it appears to be running really rich due to the smell of the exhaust.

When I first noticed the problem I checked all the fluids and topped off the radiator as it was low and it appeared to work for about a day. But now it is back and continuing the same behavior.

(I’m assuming this is all stuff that happens if a serious enough fault occurs) Would love someone to validate this.

What I've done so far:
Thus far I pulled the codes on the truck which was a 33 and in the Haynes manual that indicated that the EGR opening is not detected.

I’ve not tested this item yet but plan to. However, it appears from my research that this is rather common fault and often times isn’t really this issue. I’ve seen way too many posts about people replacing the EGR and several other parts to try and trouble shoot this and not having any better results even with the 33 code being displayed. I’ve also seen several posts ending with the issue being the fuel pump. I’m hoping that someone can point me in the right direction for troubleshooting the issue as I don't want to replace 10 things on the truck if they aren't needed. And this appears to be the common theme when this issue appears.

Specs of the Truck:
1995 f250 XLT 4x4
460 V8 EFI
175K mileage

Thank You for your consideration and time to answer this post.

Ford Fuel Injection » How To Run a Self-Test
Here is a link on how to check for trouble codes, if you do not have an OBD1 code reader. I think I would check for codes again as your truck should have 3 digit codes, I would think.

X2 that truck should have 3 digit codes.

I'm not one to argue especially because I'm asking for some help here. But I'm confident that I got a 33 on the code readout. I'm attaching a link. These codes are slightly different than my haynes manual but you can see they are all 2 digit codes. In the haynes manual there are some 3 digit but still plenty of 2 digit codes.

FORD 1983-1995 OBD1 Decoder

You could be seeing a 111 twice. There should then be a separator flash then memory codes.

You get either 2 digit or 3 digit codes (not both together) depending on what computer your truck has. Ford started to change from 2 digit code computers to 3 digit around 1991 so it would be a good bet that your computer spits out 3 digit codes.
Maybe check codes again, noting what EPNC says.

Ok. I'll take some video of it and post it. Perhaps I'm reading the flashes incorrectly. I'll try to do this today if possible.

You would have three digit codes in 1995 unless someone has replaced the computer with a wrong older one.

Do you have an automatic transmission?
Is the trucks fuel system stock?
Any other mods (SFI/MAF)?

That link has some wrong definitions or at least on the wrong lines for the numbers beside them.

I would not go by anything the Haynes manual says either.

That code 33 means the EGR valve did not open and that will not cause what you are describing.
Continuous Memory Code 33 indicates that the EGR valve did not open with the engine stabilized and with EVR solenoid duty cycle present sometime during vehicle operation.

It sounds like you are running in limp mode and when the computer puts you in limp mode it will set another code as to why it put you in limp mode. A 33 will not put you in limp mode.

Or you have a bad FPR. Take the hose off the nipple on top and turn the key on and off and see if any fuel comes out of the nipple on top. If it does the FPR is bad. It could also be that the fuel pressure is too high. That would also be a bad FPR or a pinched return line to the fuel tank(s).

Subford,
Thanks for your response. I think you are exactly correct. The truck is in Limp Mode. I'm going to answers your questions as well as attach a video. Perhaps I've missed the code.

in the video it looks like 33 - 1 - 33 but maybe it is 331 33 or 33 133 I didn't have a 331 or 133 in my Haynes manual or anything on the above link in the post.

Regarding the other questions: I don't believe an older computer was used. but I'm the 4th owner so I can't say 100%

The truck is Automatic
And from what I can tell has a stock fuel system.
No mods that I'm aware of.

Video should be linked below. Perhaps I'm reading the code incorrectly.
1995 f250 check engine codes - YouTube

You all have been very helpful thus far. I'm really appreciating all the tips. This is a very frustrating problem to nail down.

It looks to me like KOEO 111 111 & CM 111 111.
That is no codes so the computer may have had the codes cleared after it has ran last.

Now you need to run the KOER self-test.

I agree with Bill. It looks like 111 and 111 to me too.

I'm convinced that you are correct on the 111 code. And I'm still getting the same codes for KOEO codes.

I also ran a ER code as well and got 632 about the overdrive cancel switch.

Just a note the check engine light wasn't on and it wasn't in limp mode at the time. When it goes into limp mode has been unpredictable. I would like to pull the codes when it is in limp mode as well.

Dont know if this helps or not. I'm still at a loss on the limp mode settings

Does anyone have any advice if I'm getting 111 yet the truck has been in limp mode. I dont understand why the CR codes aren't showing either. Would welcome any seasoned advice.

I've been looking at options. I'm taking a guess here that since this is intermittent that perhaps it could be electrical? I've seen some people having issue with the ECM in the past with a similar issue. Any thoughts on this. At this point I'm looking for avenues to troubleshoot. So if anyone has any ideas shoot!

Here is some information on Limp Mode:
What is Limp Mode?

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