I'm just so mad at the truck just about the only thing I can try next is change the eec or computer then again what about the map sensor?

 

Usually when we suspect a plugged exhaust we remove the O2 sensor and if it improves we go from there. Since we can't keep it running long enough to check with a vacuum gauge Is there any way you can remove the O2 sensor or separate the exhaust before the converter? Do you have another MAP sensor to swap with?

 

The answer to that question is no. as the exhaust goes and this was the way I got it
after the cat it goes into one strait pipe and splits again just before the drive wheels and out the rear corners of the truck no muffler at all. and I don't have another map sensor to swap with. if it doesn't cost too much I might go get one and change it out just to see what it does.

 

OK, I'll get a little basic. The MAP is manifold absolute pressure sensor, the TAB and TAD are (respectively) the Thermactor (air pump) bypass and divertor valve. Of course, the EGR control valve is self explanatory.
As I said, the only thing the engine (in this version) needs to run (electronically) is the distributor, IAC (idle air control valve), and MAP.
Another thing I'm NOT seeing here is test results. As my father said, "the engine only needs fuel, air, spark, and it has to be there on time." He's right, and I base All my diagnostics on this mantra. Not the most poetic, but it still holds.
You might want to go take a break and come back to the truck. Sometimes when I put problems in the back of my mind and come back to them, things start to make sense.
Another thing to do here. Start with this:
1) What are the fuel press. test results? Is there any fuel getting sucked into the engine from the press. reg. vacuum line?
2) What codes does this thing spit out? A Faulty MAP sensor (which is the major, controlling input for eng. load in this powertrain) is very, very powerful.
3) What is the spark like? Nice and strong, or just kinda yellowish?
4) When all else fails, what is the compression like?
5) Since you've been at this a while, what kind of shape (generally) is the truck in? The worst problems I've ever encountered in vechicle usually come from the ones that "ran great until yesterday", when everything went bad.
6) Have you seriously considered a really tough to find wiring problem? It would be easy to explain all these problems with this problem. If you started off by mentioning that the o2 connector is melted, remember what I said about the battery cables and shorting out?
7) I know (believe me, I KNOW) what it's like to get beaten up by these things. You might want to start over and see if 1) you have a possibility of a good running engine underneath this problem; and, 2) How much work might be required. Is it worth saving?
8) And (I'm not being nasty here, so don't take this the wrong way): Something in one of the areas that I listed from my fathers little sentence MUST be the problem. I think you mentioned looking at the timing chain/marks, so I don't think I'd start there.
I wish I could just look at this for a few minuets, but I have to trust your results, so Please list everything in your replies; did this start all at once, or just over time? Does it do this hot, cold, and inbetween or just cold? If you take your foot off the gas, does it just stall, like the key was turned off, or does it just 'float' for a moment before it dies?
I know it sound like a lot, and it is, but I can't be there looking over your shoulder. All I can do is help to interpret test results.
And if you solve this problem, I'll send you all my evap. system leaks or transmission problems in the new cars. You'll love some of them!

 

it was running just like new one until I put in gear and it all went to hell. the color of spark is like a lightning bolt coming from the coil.(blue almost white) i'm obviously getting fuel to the pistons maybe not enough but it is getting there. no there ain't any gas coming out of pressure reg. vac. hose either. My new code reader said that circuit is faulty the #'s are 542, 10,(whatever that means) it ain't in the book. I don't have a pressure tester and can't get one. the comp. is damn high cause when I had to
in a new high volume oil pump the engine was looked to have been rebuilt with no sludge or carbon on or in the crank case it hasn't used any oil since I've had it.
So that means that this truck runs and drives like it did when it it came out of K.C. factory. It is the 16' wheelbase. Ive used this truck to haul anything and everything that it would carry or pull on 16' trailer the tranny is auto with the cooler lines stacked on top each other and never slipped or failed in any way and has never been low on fluid. I know this reads like I'm insulted from your last post but, I ain't. If I have to drop any one of the tanks then I'm f;@!$d 'cause I'm unable to disconnect the frigging filler tubes they designed those things with a hose inside one another go figure. so is there a high pressure pump that I could put in line before the filter that would raise the fuel pressure to the engine?

 

I think maybe reason for the code of 542 is cause someone bypassed the relay on the fuel pumps when the key is on so is the pump depending on which tank I want to use and this doesn't bother me at all. it's been this way since i've had the truck.

 

I just burned the second starter up on this stupid thing so I really have to give up on it.
As much as I love it and tried to fix it it has been the best one thus far but I can't do it.
I thank all of you for everything and all the advise that y'all gave me. on a way better note I almost can't wait until I get the one that I've been trying to get all along, A '77 F150 with a 460 and c-6 I know that I'll have a better understanding of how it should and will run. Again I thank y'all very kindly especially you Hanky and Greasemark.

All the best
Floyd

 

Thank You Floyd.
I learned a few things about you during the past posts and The little bit I learned is you will not let this truck lick you! And that's good.
Until your personal batteries get charged again, can I make a suggestion?
You know how to use the internet, now surf around and try to pick up as much info as you can and you will find the stuff on your 92 isn't that complicated , it only seems that way because you are new at it. Enjoyed working with you and now I have to go and clean some more stuff from between my toes ,and as you can see I stepped in another one . Whether we fix it today or the next day is somewhat important, but more important than that is, we'll stay on it until WE DO FIND IT & FIX IT ! Stay in touch !

 

I just wish that the designers for all auto makers would have kept it simple instead of being too smart to learn anything. Granted I ain't that smart. What little I do know is 'cause my daddy (may he rest in peace and sing around that great white throne)was a man who found his mechanics calling while he was in the marines. Therefore he told his boys that if and when we each got our first car or truck if it breaks down then you will fix it yourself and that way if it happens again you'll know how to fix it, save yourself a few bucks in the long run. That being said, fuel injected motors run awfully good when they don't have any problems. but, when they do go bad as anything made by man does, it gets to be a really big and expensive problem. Please don't worry about me keeping in touch 'cause you know damn well that I will!!!!
Now Greasemark same to you. And know this my first love of any make will always be a Ford. I have never had this many things go so wrong in one truck or car before regardless of make or model.

 

No offense taken. I can still remember about 3 cars over the years that I couldn't fix. I wish I could have them back. While they beat me up, I don't like eternal mysteries, especially with something mechanical, I ALWAYS learned something (more about myself) when I was confronted with what (at the time) would seem like an impossible problem.
And I would like to say something to you Mr. Grindman. You may not consider yourself very smart, but keep this in mind from someone that has a good IQ, with a double major from college, and still makes his living working on cars; and I want you to listen well. YOU ARE NOT DUMB! (or should I say 'unintelligent'?)
If you had the gumption to fix the truck (given all it's problems), and you were at least familiar with the landscape under the hood, then I can't fault anyone for trying. I've had to eat a lot of crow, and I'm man enough to know when I was wrong about something or not smart enough to fix it. The info here is free, and for the people in the trenches every day (I can say the Hanky definitly has the basics down and is NO slouch on just about any topic that I've seen him comment on), and I know that I'm no beginner.
That being said, if the two of us couldn't pinpoint what was going on, then I doubt very seriously that it was something easy. We've worked on these for years, and even though I can fix a lot of easy problems and make a lot of money doing it, it's the tough ones that stick in your mind and teach you the most, even after they're gone.
One other thing. The code 542 means that the fuel pump secondary circut was open when it should have been, and was commanded to be on. In a dual tank setup like you had, that means it was the tank it was switched to when the code was set.
I would've loved to hear what the pressure readings were, because this was sounding like a fuel starvation issue.
And I don't fear fuel injection at all. They are relatively easy to fix. The worst problems on any car are the things that everyone takes for granted, like good wiring, a processor that works correctly, and grounds that are clean and tight. These are the problems that everyone hates to see.
Get back up on the horse again, and the next time you have a problem with a car, just give us a buzz. We'll be here.