I have a 1990 f150 with a c6-4.9 300-6 combo. I had the trans rebuilt and the mechanic told me i had a vacuum leak, so i looked over the vacuum diagram, and apparently almost all of my vacuum were in hte wrong places. so i rerouted everything, and now they are where they need to be, I pulled the clip out of the harness next to the distibutor and reset he timing according to the manufacture specs, disconnected the battery and then put it all back together... test drove it, it seriously lacked power at akeoff, so i adjusted the time by ear while it was running... test drove it again but wasnt much beter... is it possible the way the vacuum was before was fine???? or maybe i should keep going with adjusting the distributor by ear???? and what does a bad EGR smell like??? there is a wierd smell coming from the motor... its not mothballs or sulferic, so im sure its not the catylitic converter... , im soo lost right now, if anyone has any ideas, please let me knopw, i read somewhere that blocking off the egr is better...

 

egr's don't smell. They open a hole into the intake manifold creating a BIG vacuum leak.

 

OK, heres an update. I have gone through all the vaccum lines, even gone to ford to ask abotu wich vaccum sensor is which... very un-informative gentlemen.... so after doing some reserch i came to the conclusion my vaccum sensors were in fact hooked up wrong, fixed them... then if you know what im fixing to say, youll understand the can on the passengers side fender.... that coffe can reservoir... it had a crack, very hard t osee when dirty... i rtv it but it didnt hold.... so ill be buying a new one hopefully.. now, all that stuff aside, i re-timed the ignition. its dead on 3 degrees btdc.... idles great, BUT when you put it in gear and gas it, it bogs down and even backfires into the intake.... what does this sound like to you guys???? bent push rod??? warped intake valve??? cracked head?????

any ideas greatly appreciated. im going to once again change my fuel filter, i just did it 3 months ago, but ill do it again just to take out hat option. cap and rotor are fine ,plugs are fresh, no cracked vaccuum lines, mostly new now. new throttle body gasket.

anotehr wierd thing, my floor vents are on now when they are supposed to be off.. .any ideas?

 

All of that still sounds like youre fighting a vacuum leak. Do you have a vacuum gauge?

As for the floor vents, you should be able to solve that with some investigating. What is connecting the dash to the control doors? In my Focus, it's a rather cheesy cable set up ala bicycle brakes...in older vehicles, many used a VACUUM operated control port.

Happy hunting!

 

no i dont have a guage.... was looking into buying one, but i havent a clue on how to install one, plus all the fittings looked like they were threaded, i dont have an extra spot on the 300-6 for a threaded vacuum fitting.... if i do, i dont know about it.

LMC truck wants 50 bucks for a new coffee can vacuum reservoir.... just rediculous, ill weld it at work before i pay that much for a coffee can.

 

well, im stumped.. i still get random backfires into the intake, mostly when its cold... and the power isnt there still, what i have done so far is:
new lifters and push rods, new plugs, fuel filter, clean all the intake and throttle body, new pcv valves, fixed ALL vacuum leaks and quadruple checked the timing.

MOTOR /Trans : 4.9L 300-6 C-6 combo

What is happening is, when i go to work in the morning, i go to start it and it acts like its not getting enough fuel, as i throttle the truck it bogs down, ITS FUEL INJECTED!!!!! i should not have to pump the thing to get it to run.... my step dad says he thinks its the coil, but a coil usually gets aorse as they warm up, not the other way around right? i guess i could check the ohms on it. we cleaned out the cap and rotor for any carbon tracks, still the same. this really sucks for me since i just spent 1400 to get he tranny rebuilt. does anyone have any idea what else i should look at?

 

I need help, from anyone who has a early 90's ford with the fuel injected 300-6.

What i need to know, there is a set of vacuum switches that bolt to the valve cover on the drivers side of the cover. my truck has 2, newer models have 3, what I need to know is, how do i tell the difference between which ones are what switch, when i rebuilt my engine 7 years ago, i put an aftermarket valve cover on the motor, and relocated the switches to teh firewall, i think i rotated them and have them hooked up wrong, I went to Ford and the idiot insisted that all i had to do was look at my diagram of which one is which, but what he failed to hear many times was the fact hat i may have rotated them and that there is no markings on them to tell which one is which, he even printed of the same diagram as the sticker shows under the hood... if you know which is the TAD or w/e it is versus the otehr one, please post a pic or a diagram showing the switches and how to tell which one is which, PLEASE.... any and all help is greatly appreciated.

PEACE

 

Not to ask a dumb question, but why not simply reverse the installation of the vacuum lines and see if it runs better or worse?

Worst case, the truck won't run at all and you'll know that you had them hooked up correctly.

 

did that, the vaccum lines are correct, i found a diagram showing which way the yare supposed to be mounted and lines atached etc...
now i have a new problem, today we dropped the fuel tank and replaced the fuel pump strainer, the old one was clogged bad, i figured this was the cause of the lack of power the engine has.... well, we rinsed out he tank with fresh gas, and put it all back together.... the truck actually RUNS WORSE NOW! ive adjusted the timing, but it dont change it, this thing acts like it doesnt want o run at all.... i have a question... i knew that when a fuel pressure regulator goes out, it usually leaks fuel out of the vacuum line fitting on top, now, this one doesnt leak, but when i take off the vacuum line to he regulator and cover the vacuum hose, nothing changes, now i figured it would at least run rich and stutter teh motor right? i think tommorrow ill take it off, replace it with an older one and see if it runs different, mayeb the newer one is just stuck????

 

Good possibility. Or maybe a crack in the vacuum line somewhere?

 

ok, today i took off the current fuel pressure regulator... put an older one on, same story, have to pump it o start it, and to keep it runing, so i know its not the fuel regulator.... now i took off the vavle thingy off the top of the throtle, almost liek a electric choke of soem sort... its seems to be free and not stuck.. so now im researching throttle body sensor, fro mwhat im reading, this 25 dollar part could be my problem.... i guess ill have to swallow my pride and buy it.... try it out... nickle and diming my *** to kingdom come i swear... i still cant fathom why after i replaced the fuel pump strainer, its running worse..... its just beyond me, is it posible the fuel is flowing too freely now??? lol, what a headache... any more help would be sweet, my engine specs are: 1990 f150, 4.9 (300-6) fuel injected. repalced parts sofar, new lifters, intake gaskets, cleaned throtle and upper intake, new plugs, wires, bug and rotor, fuel filter and fuel pump strainer... any help would be awesome! thankyou

 

My thoughts are TPS or IAC!

 

i cant afford a new anything right now, so depresing, i know now the fuel pressure reg i put on this morning is bad, so i put the old one back on.... as for the tps, i multimetered it and it moved smoothly, its 40 to replace it so im screwed.... i unplggued the o2 sensor and it actually idles now, but as soon as i touch the throttle it wants to kill it... anybody have any fuel injected 4.9 parts that I can have for free???? lol worth a try.

as for the iac?? idler control valve??? what is the iac and what does it look like?

 

Idle Air Control valve. Not sure on your application, but on my Escort, it was a small rectangular box with two screws holding it in place...$20ish to replace.

 

sending truck to ford garage tommorrow to have it troubleshot and they can let me know whats wrong...