different day, different problem =/

[87Rangerdude]

ok, i finally got my truck running and registered, but i've got a new problem now. whenever i get up to over 35-40mph the truck sputters, backfires a lot and then it dies if i cant keep it running by pumping the gas and putting it in neutral, its acting like its getting too much fuel, but i thought i fixed this problem by tuning the carb, but apparently that wasnt the problem, also it sounds like it loses spark when it happens. i've checked all the plug wires,coil connections. when i pull to the side of the road and let it sit for a few minutes it starts right up and drives fine until i get up to speed again. if anybody has any suggestions they would be greatly appreciated, thanks

edit: the truck is an 85 2.8 auto 2wd

 

[87Rangerdude]

it idles shitty afterwards too

 

[Original_Ranger84]

Sounds like either a vaccum leak or a bad case of carb Icing. Does it get pretty cold where you live? And is your timing set or dizzy loose?

 

[87Rangerdude]

might be the timing, i havent checked the dizzy out yet, only to make sure all the plug wires were on tight, when i open up the dizzy what should i make note of? oh, it cant be carb icing, i live in florida

 

[87Rangerdude]

how do i set the timing on the dizzy?

 

[litleblue]

What type of ignition do you have. Duraspark or TFI (stock feedback system)?

 

[87Rangerdude]

stocker TFI, hoping to do a duraspark conversion when funds are available

 

[litleblue]

Unplug the spout connector leading to the distributor. Single connector usually a green/yellow wire. Check timing with a timing light, set timing to 10deg btdc. Turn off engine reconnect spout connector, restart engine, with warm engine recheck timing this time (calculated timing) should be about 27btdc.

Your discription wouldnt lead me down the timing route. I would check fuel delivery system. Carbarator Icing is a big problem with these 2.8 feedback rangers. Ford had many TSB's on this problem, they even went as far as to install a heeted carb spacer. Icing accours when the dew point temp and ambient temp are very close. IE: 40 deg F outside air temp, 40 deg F dewpoint temp or 100% relative humidity. Although this might not be the problem when the truck starts to run shitty, stop along the side of the road, pull the air cleaner and check down the carb you may be suprised and find frost built up on the throttle plates and venturis. if this is the problem make sure the heat riser (stove), flapper valve and thermastat located in the air cleaner is working properly.

Also make sure you pull codes and post them if the above isn't the problem.
Dont start replacing stuff just because a code is displayed. A perfect example is code 41 oxygen sensor lean. Most likely the sensor is correct there is a vacuum leak or the feedback valve is leaking (back of the Carb). Repairing the vacuum leak and/or the feedback solinoid will clear the code. A new O2 sensor would most likely repet the code. A good idea to post the codes first.

 

[Eric Kropp]

If all the emission equip. is still installed and functioning(?!) I would check the map sensor.

Eric

 

[87Rangerdude]

well i got it back from the shop today, they changed the timing, tuned the carb and put a brand new fuel pump on it, and its still doing the same thing. it seems like it does it the most at around 38mph right after it shifts into 4th gear. its acting like its not getting enough fuel, but i know it is. im so confused

edit: he said the brake booster is junk in it too, if that would have something to do with it

 

[enginepaul]

"he said the brake booster is junk in it too, if that would have something to do with it"

That would be a possible vacuum leak. And while we are on vacuum leaks, those hard plastic lines - the colored ones - have a tendency to get brittle, crack and leak.

 

[87Rangerdude]

i bought another brake booster/master cyl from a junk yard, ill know tomorrow if that solves my problem