95 5.0 2wd auto 3.08 rear. 195k

She now runs , shifts, and brakes nice and smooth. About the last thing that I'd really like to eliminate would be what I assume is detonation under full throttle (I drive like grandpa but sometimes pass and freeway merging).

The PCV, EGR, O2, catalytic converter are all orginal (not changed).
I've set the timing to 10btdc, cleaned the TB, and MAF (helped alot).
She seems to respond to 97 gas

Will changing the above sensors/valves help?
What you all recommend?

I've read some about the seafoam vac line deal but it makes me a little nervous-could the detonation come from a load of carbon build up?

Thanks for any info.

 

Absolutely! That's why it responds to high octane fuel. The deposits artificially reduce your c.i. displacement thereby increasing it's rate of compression. The deposits also wick unignited fuel which then detonates out of sequence. Your 02's definitely pooched by now also! Seafoam, Lucas fuel injection cleaner, o2's, lay off the hi-octane! It just starts the process over again. Octane only controls/delays the point of ignition. It decreases overall combustive properties.

 

Thanks for the reply. I changed the PCV yesterday, pulled the EGR and scrubbed it out with brake cleaner and was amazed to find that most of the hard downshift clatter had disappeared!

I'll go ahead with the o2 also though, cause by now it's probably registering oxygen from the rust process instead of the exhaust.

Thanks for the help!

 

Trust me on this on. Seafoam, before the o2 replacement! 1/3 through the power brake booster Vac line at operating Temp idle. Shut off for 15-20 minutes. Restart & blow it out w/ rpm revs. Then take it for an aggressive run.
Toss the rest in the tank, unless your planning on changing the oil in the near future. If you are, 1/3 in tank, 1/3 in oil. You will immediately have a smoother idle & better throttle response. (and less detonation) With your condition, you may want to do a whole bottle in the tank. http://www.youtube.com/watch?v=zt_oX...eature=related This shows how to for Carbed, & EFI.

 

Thanks for the tip. I've put a couple of cans through the tank already. Guess I'll try the vac line deal. I'll let you know how it worked.

Thanks for the vid - big help.

 

GOOD LUCK !!!!!!!!!!!!!!!. I have been dealing with the same issue and CAN NOT find what is causing it. My next step is to have the injectors professionally cleaned.

 

Have you tried Stock Motorcraft Nic plated copper core plugs? They produce less combustion chamber temps. than Platinum's! Their only drawback is they don't last 50K miles & they don't self clean (by producing a drastically higher temperature) But if your plugs are fowling, wouldn't you like to know about it? And I like to look at my plugs more than once every 50K anyway. It would be a $15 experiment + elbow grease.

 

yep tried them and no difference, in fact I still have them but I did put the platinums back in. I am fixin to put on headers, I bought the Ford Racing shorties. The manifolds I could find were junk so I elected to put the headers. I will find out if these will help my problem or not. Next I guess I will start throwing parts at it. The truck feels like I am towing just to take off. Its not near as bad when its warmed up and been dirving around but it still does not have the power I think it should have.

 

Many times a repair shop will retard base timing to like, 8 BTDC to try to bury a ping problem. One side effect is poor acceleration from a stop because the timing curve is now farther up the RPM range. I remember the beginning of your adventure w/ this. The only bear we couldn't kill. Seems like only yesterday, but it sure aint! Good luck! If you ever figure it out, let us know. I (we) threw every trick I had in my bag at it! Still in the same line of work?

 

yep still the same. I have tried retarding the timing but it does make it more sluggish than it is. I think my next step is Im going to have the injectors professionally cleaned and balanced. I found a place around her that does all 8 for like 200 bucks. I have to remove them and reinstall but they only have a one day turn around. I figure with 180k it needs it anyway

 

Might want to consider replacement. Test pressure bleed down time, w/ a pressure gauge on the fuel rail. Maybe some are cracked. Cleaning won't help that. Ask them to consider that. Having to replace them on top of cleaning would be good for them, but not so good for you! Something's defiantly wacked, because you should be able to run 14 BTDC w/o a problem, and as you know, you sure couldn't do that now. Probably a little sketchy at stock 10 BTCD base time. I'm leaning towards an injector problem, but exactly what's the problem? If rail pressure bleeds off slowly, a cleaning is in order, If it drops off like a rock, your probably looking at injectors that are compromised.

 

Thats really what I was thinking. I still dont throw any codes and in fact the Super Unleaded dont even get rid of it. Thats one reason I think its just startving for fuel. The injectors are not matching the amout of air coming in when the throttle is opened that much. There still is no codes. I would think if it were anything else it would throw codes

 

Jeff, have you tried getting a BG or Motorvac job done? You may have a crapload of deposits in the chambers.

 

Running super redundantly in that engine can do it all by itself. After a period of time, it wont run w/o it. This ping problem's been going on for a long time, & he hasn't had much of a choice, needing the truck for transo. Have you done a fuel pressure check w/ bleed down?

 

no I have not. I have not had time. I didnt drive it much before. I have a take home car issued to me. I have thought about the fuelpressure test but have noot had the time lately. my son in law has been driving the truck. I am waiting for him to get his car back

Where can that motorvac - bg be done