I am trying to diagnose a rough running 1998 F150 (new to me) with 184,000 miles, 4.6l ,the code is misfire on 3&4. I changed plugs, (the old ones looked good), I changed wires(no change), and I get a great spark when I pull the wire off the coil pack on #3 but whether I let the spark jump or whether I pull it away I get no change in speed of the engine, I assume from the great spark that it is not the coil pack. I assume the cylinder is not getting fuel (the plugs were not wet or black) but the injector clicks OK. Does anyone know if it is even possible for a clogged injector to cause a misfire code?? Also got a low fuel pressure on rail two code which I assume is unrelated. I am new here since I just bought the F150. Thanks in advance for some insight on this.

 

yes as plugged injector can cause a missfire. pull the rail off and see if the injector has something blocking it. if not get the injectors flushed.. but at it being a 1998 model... u might be better off looking on ebay for some new Gen III bosh injectors thats what i have on my truck and it runs much smoother. and it generates a better fuel plume. so better fuel milage.

 

Yup, just like the one's I purchased off ebay -

http://cgi.ebay.com/ebaymotors/ws/eB...MEWN%3AIT&rd=1

smoothed out my 98 - made a noticable difference , VERY noticable..Changed injectors @ 167k

 

yeh u had to change the injector connectors out on those to? i got some off a explorer for 48 bucks on ebay. that were the same connector.

 

Sheeeezz!!!!!!!!! Nothin gets by you.......

http://cgi.ebay.com/ebaymotors/ws/eB...MEWN%3AIT&rd=1

I did get lucky on these tho - they were indeed new and never used , bone dry no gas smell....still had that new injector smell ,lol..They did thro me curve somewhat after install, the truck wouldn't start!!! I got cheezed off and pouted for a day, went back in the barn to go back over my wiring figuring I messed up somewhere and just for the heck of it, tried to fire her up again - "it's Alive" lol.. Had air in the lines, more than usual and unprimmed injectors didn't help..duhhh!! All in all, can't beat those ebay deals.

 

haha nice!. my injectors didnt give me and problems. only thing is im now maxed out on stock 19lbs. im probably going to bump them to 24's soon.

 

Thanks guys!! this is good advice and I am an eBay addict (feedback is 612) can you tell me if this item is the right one? (the guy is going to re-list) there seems to be two styles and I do not know how to detect the gen III design
http://cgi.ebay.com/ebaymotors/ws/eB...MEWA%3AIT&rd=1

 

the gen 3's are the skinny noisy ones those look like what is stock on ur truck which is either Gen 1's or 2's

 

I might have too , depends..serious thinking of supercharging (pro-charger) If I stick with a two core intercooler I can run my 19's and they say no prob w/stock comp., if I opt for the three core , then I need a bit more - 42's most likley, the stock comp would freak, I'de need a tune, trying find out who has a dyno in MI close by if I decide to go for the gold - the only place I new of is closed down..