Ok, my 4.6 and I need help. I have a '97 F-250 (LD) 4x4 with the 4.6, about 103,000 miles. I have had the pinging problem, have cleaned the EGR, DPFE, and MAF, replaced plugs & wires about 10,000 miles ago. For the most part, this solved the ping, except under a very hard load (towing up hill or going up hill w/ the cruise on). Last week I could not get it started, once I finally did get to started, it was skipping, and had no power. I broke down and took it to the Ford Dealer in my area, since many of the local garages do not have the computer equip to pinpoint problems. The Ford garage tells me that cyl 1 & 4 were not firing, and the rest of my cyls were running at less than optimal. They contributed this to my tune up not using Ford plugs & wires. They went on to say how Ford parts are specifically desgined for thier systems, and after market stuff just does not work. I was amazed!! I used top of the line NAPA wires and Bosh double platinums for plugs. They told me that the wires were not transmitting the power the way Ford wires do, and cyls 1&4 ran fine with Ford wires, but not with mine (seems to me I had two bad plug wires).
So here is my question (s). Does anyone have similar problems, and how were they fixed? Comments on brands of plugs and wires? I want to fix it soon, but don't want to chase my tail fixing things that don't need it. Also, I am intersted in buying my own computer reader, thinking of an AutoXray, any comments? Thanks for the help, I sure do appreciate your input.

 

Normally your factory parts are better than stock, maybe not for performance but they will outlast aftermarket no doubt. By the way wtf is the dpfe?!? I have heard people talking about it but what is it? Sorry about your prob. I only have 34k on my truck so no troulble yet. Good luck.

 

Hi F250ld

Im not clear here...what exactly did the Ford shop do? 2 bad wires...did they replace all wires/plugs etc???

Also...does your engine use the coil packs...(2) each firing 4 cyls?
If it has coil packs...were they OK?

Did they do a diag. check (OBDII)?

Ive also seen where pcm's have been replaced. So much is controlled by the PCM...just not simple anymore.

You can clean parts all day long...but how do you know that part is working properly after 90/103K+ mi?

Trial/error/testing parts etc...not easy for the DIY, unless you are real sharp/ have testing equipt/understanding what test means. As an example..testing pwires...run continuity/ohm test. This test not complicated...but others can be. Im limited on testing.

i agree on spark plugs...really! Dosent mean your plugs are bad but have seem it before nonOEM VS OEM mcraft. Switching back to OEM mcraft maybe better? Your bdpp's/wires seemed to be working ok until recent problem...so ???

I dont know about axray...maybe someone here can help more.
I havent done tune up yet.

Good luck...OT

 

It seems like everyone always assumes Ford's orginal parts are always superior in durability to the aftermarket parts available out there. I'm sure to some extent in some cases this is true, but it's not the case all the time. When Ford needs a part, they take the lowest bidder to manufacture the part under Ford's specs, not pay to have the most durable part available out there manufactured. I think for the most part the 'quality of original equipment parts' is somewhat overrated.

 

I've had the same experence with my 86 Ford T-Bird Turbo coupe. Spent good money on great plugs and wires and it ran like crap. Shop (not a ford dealer) told me to try ford original plugs and wires. For whatever reason all the parts work good together. Your results may be different.

 

No one else knows what a dpfe is either huh? By the way I have yet to use an aftermarket part that outlasted oem.

 

S&B,

DPFE (Differential Pressure FEedback) is a "sensor" which converts exhaust pressures to a voltage signal used by the PCM to open/close the EGR valve.

Bill

 

Thanks for the comments and help. The Ford garage only read the computer, told me that I needed to use Motocrraft wires and plugs, that would solve it. I replaced the wires, absolutley no difference. I have cleaned the MAF, DPFE, and EGR, replaced the PCV, and after consulting with a few people, we have feel I have a tank full of very, very bad gas...I am going to try to drain the fuel, and start over with new fresh fuel. It is absolutly amazing how sensitive these new engines are. Still looking for recomendations for scanners though, want to buy my own, so I may read codes and trouble shoot myself instead of running to a garage. Thanks for the help.

 

From my experience with a '97 F150 SC 4.6l with 106,000 miles on the clock, I think they're zoomin' ya.

I have NEVER had a pinging problem with this engine. I bought it with 37,000 mi; put in new Bosch Plus 4s at 45,000. New lower end NAPA plug wires and Autolite platinums at 100,000. No problems whatsoever! Ford products may be good, but they are overpriced and some aftermarket parts are BETTER!

Seems to be lots of pinging with the FOU1 PCM, too.

I also would check the coil packs, then see if there is a Ford PCM reflash bulletin for yours...seems that on occasion Ford sees fit to update the programming in these things.

Also, from various posts:

1) Chevron Techron or other EFI Cleaner
2) Clean MAF Sensor with Q-Tip or Electrical Spray
3) Clean DPFE Sensor
4) Change Spark Plugs and Gap Correctly
5) Clean EGR System and Intake Manifold
6) Clean Throttle Body
7) Program to compensate for pinging from Mike
8) Timing Adjuster from Steeda
9) Remove Octane Compensator/Bar

A lot of the above deal with various system components having carbon in them.


If you check out the prior posts on this topic, there is a wealth of infomation on this topic.

#7 above refers to the octane table in the PCM. Maybe just buy a SuperChip and be done wit it.

Good luck!

 

I hear what you are saying I had the same problem recently with my 97 4.6 with 120,000 replaced the orig. plugs and wires seemed to solve the missing and stumbling. But 2 weeks and 600 miles later it seems that it needed a coil pack for the #4 cyl. that was missing. Pulled the coil pack and found it out of spec. both primary and secondary resistance were out and since I have replaced it 1200 miles it now runs just fine. I went with stock plug wires and plugs but ended up buying a Sturdy coil pack about $150. Be sure to check the resistance across the coil pack before buying a new one and remember that they are cross fired it may be on the oppsite side from the missing cyl.
Good luck.

 

Waht are the readings supposed to be?

 

Had to locate my Haynes Man. where I put all my notes.
The book says Primary Resistance 0.3 to 1.0 ohms mine was reading between 1.2 and 1.7. The reading for Secondary Resistance is 6.5 to 11.5k-ohms and mine was 13.42 to 13.47.
Way out of spec. in both cases so it was easy to see that was at least one problem that needed attention. Thank-fully that seems to have solved the problem. I will most likely replace the other soon since they are the same age and were under the same conditions if one failed the other is not far off.

 

From experience (been in the business 17years now), I wouldn't use Bosch platinum plugs in a lawnmower. I have seen way too many problems in all makes and models when these plugs are in.

Two things are most common, bad hesitations and pinging.

I also would NEVER use napa parts on anything, (I work for a now FORMER napa service center) We lost more money on bad parts, their brakes (especially for trucks) and igntion wires are the WORST of all. So many comebacks and problems, it just isn't worth it.
Now we go with only OEM parts, they seem to last the longest, and really don't cost any more.

If you want to eliminate the ping, use NGK plugs, non-platinum, you'll have to change them every 30k, but they are cheap and have stopped many vehicles from pinging that I have worked on.

 

I have had problems with aftermarket plug wires. I have had to sets of "top of the line" plug wires that didn't seal and caused the spark to jump down the sides of the plugs a leave a carbon track. I have also had plug wires that don't seal at the top and let water get down around the plug and rust it out. I finally replaced these wires with Ford wires (not much more expensive) and haven't had a problem yet.

As far as plugs....I use AC and haven't had any problems.

I guess I should've left the original wires on considering they weren't giving me any problems. An expensive lesson at $120+ for a set of plug wires, but a lesson well learned.

 

Thanks for the responses. I drained the gas, and now it runs ok. Not quite perfect but at least it goes down the road with out bucking and stumbling. I do believe though that I will change out my plugs to Autolite double platinums or NGK. I have not been impressed with those BOSH plugs. I changed oil yesterday, just to make sure to get all that un-burned gas out of the system. Also have been running it around town, and man you should see the black smoke when I stomp on it and hits passing gear! Two weeks, a trip to the Ford garage, new wires, new fuel filter, new PCV again, cleaned the DPFE again, cleaned the MAF again, and problaby a new set of plugs from a tank full of bad, bad gas. I'll keep you posted. I think I will check the resitance on my power packs as well, just to be sure. Love the truck, thinking of an FIPK II, and maybe a chip for the future..... Thanks again for the help. It's a great site for info and help.