I get code #2 misfire. I did complete tuneup plugs,wires,etc new injector on #2 clinder, fuel filter, idle motor, both 02 sensors and fuel pressure regulator, all new vac lines. I have a 96 ford F150 4x4 4.9L auto Duel tank here is my fuel pressure 43psi key on engine off and 40 psi running. I think the specs are 50-60 psi key on engine off and around 45Psi running. It has kinda missing but driving down road smooth but no mather how I adjust my timeing the miss is still there. I double checked everything. Can anyone help me I'am stumped.
I got the timing right yeaterday a is which was hard with a rough idle. I let it run for a while and cleared all codes and called it a day. Today it started up great it was smoother than it was and then at other times it will kinda have a rough idle kinda comes and goes. I think maybe with the timing being off give me a code Cylinder #2 misfire becomes it's gone now. YES I only had cylinder #2 midfire. This is my dads truck I'am working on it for him hard my dad has cancer with 3months to 1Year to live so I'am working hard to get it perfect. when I have just a little miss it bugs the hell out of me on any car.I'am a pretty good macanhic and work on other people cars.
HERE'S WHAT I REPLACED
Fuel pressure reg
Egr and cleaned port
motorcraft platium plugs gaped at 44 and autolite wires best distribitor cap rotor button
Cleaned MAF sensor
Snice cylinder #2 was missing and I know was getting spark I though it was fuel related so I removed plemtium replaced #2 injector put back together and checked for all and any leaks.
Cleaned trottle body
replaced idle control motor
replaced both 02 sensor
all rubber vac lines
Lucues deep clean injector cleaner mixed with seafoam lol
changed oil ( no milk change or anything like that)
flused cooling system new anti-frez
Today my dad can't drive do to cancer but loved his ford F150 so my mom drove it today about 30 miles and when they got back they said it ran great real smooth. I then checked the codes with my $250 scanner 0 codes none. The only thing is kinda idles rough and then smooth out. IS there something with these duel tanks that will mess up your fuel pressure to causes this problam? Is there a switch around the tanks? Is there a litlle 4.9L problams like other motors I know thats common. On this truck both thanks work and on a pressure check there pretty close on fuel PSI.Now my dad is asking what each sensor do so we start talking about it.He whats me to replace the Crankshaft postion sensor,engine control module, engine control relay. Then after that I think the oil thing left is the pick-up coil.
I'am stumped lol for the first time it a while on a car lol
I would say pull the platinum plugs and put just coppers in...but since this is OBDII, that may not be the consensus here. Trucks of the OBS generation do fine on just Autolite or Motorcraft plugs.
1992 F-150 I6 4.9L 300 110K 4x4, SuperCab, Manual
1992 F-150 V8 302 156K 4x4, SuperCab, Auto
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I just seen online 96 ford f150's do not have fuel switch vavles on the rail it's in and on each fuel pump in the take. I just checked again my fuel psi new filter and regulator Iam geting 43PSI key on engine of running 40psi. The specs are 50-60psi key on engine off and I think 45 to 50psi running SO THIS CAN CAUSE MISFIRE FOR SURE.I am also getting the same psi on each tank. I also tryed a new fuel relay no help. I do not have a high pressure fuel pump on the rail like the older fords.I am thinking it's either low volts to the pumps maybe?I need to check that . Also maybe the fuel intria switch too is messing up I had this problam too on a different truck.
Any other options
No way both pumps are bad at least you think!
A bad fuel pump typically won't cause a single cylinder misfire. A leaking plenum gasket or lower intake gasket (where it seals to the head) can cause a single cylinder misfire. Also a cylinder leak down test and compression test can help pinpoint mechanical problems.
An intake leak will never "blow out" unless you have a turbocharger or supercharger creating positive (boost) pressure in the intake.
What happens when you unplug the fuel pressure regulator with the engine running? Does the fuel pressure increase? It should.
A lack of fuel condition should (in theory) cause P0172 and P0174 (System too lean B1, System too lean B2) codes. There will also typically be a noticeable loss of power as engine speed and load increases, or after driving some time and the windings inside the pump motor heat up and expand.
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