4.0L Problems

[lowlyfe_customz]

Sorry... This might be a long post....

Ok so I have been reading all of the awsome content on this site for a while. Im also a member and rangerpowersports.com... On to my problem.... Ive got a '98 4.0 super cab. Ive been having problems with it for the past couple of months with real bad missfires and rough running... A little back story first... In 2007 I had a lot of problems with miss firing and actually burnt the electrode out of one of the plugs so I changed the plugs and wires and it helped it for a while and then it got worse again so I put it in the shop and it ran me about $700.... The mechanic changed all 3 oxygen sensors, replaced one plug and a lot of stuff I cant exactly remember.... It has ran great up until april of this year... then i had a missfire on the way to work one morning. After I got off work I changed the plugs (went with Autolite 103's) and it ran good for a up until about September when I went to my parts store and got new BWD Wires. I put them on and everything started getting worse.... At current time... I still have a missfire, but it is only intermittent.... it seems to only skip and run rough after it has warmed up. I have since replaced the Autolite 103s with Motorcraft SP500s and new wires.....
Here is the link to the wires...
http://www.oreillyauto.com/site/c/detail/OMS0/9572.oap?year=1998&make=Ford&model=Ranger&vi=1304569&keyword=9572
Here is the link to the plugs ive got....
http://www.oreillyauto.com/site/c/detail/MOT0/SP500.oap?year=1998&make=Ford&model=Ranger&vi=1304569&pt=03435&ppt=C0334

The guy at the autoparts store told me that my truck was designed to run iridium plugs and these matched up to the part numbers in my manual... This hasnt helped either. So therefore I went and got a can of Seafoam... I split the can between the Vacuum Lines and the Fuel Tank. It ran good while I was testing it after I Seafoamed it and then it started back up the next day... I have let the truck idle for about 30 minutes and not a skip and the next day it runs like crap... ive checked the vacuum lines... Let the truck run and sprayed carb cleaner to see if I got a rev out of it... but nothing... I have cleaned the MAF with MAF Cleaner, Cleaned my K&N Filter on the K&N Intake I have.... Checked the IAC today... it was clean... Fuel filter is relatively new.... Checked the Coil Pack with a meter... It was good on the truck. Could it show different if i took it off? I have been researching this since the problem started... I have read on here about the 90s Intake Bolts coming loose? Would that apply to my 98 as well? I have been keeping an eye on what codes it throws and most of the time it is the same thing.... It has thrown P1151, P1152, P0304, and P0174. It has been throwing the lean code since 2007. I am just completely distraught as I cant get it to run right.... It is my daily so I need it to run right.... Any help you all can give me will be greatly appreciated.... Sorry for this being so long... Brandon

 

[1996DANGERRANGER]

well the only thing i can think of is injectors maybe??

 

[Hahnsb2]

Plastic intake manifold, right? Those are known for vacuum leaks.

 

[lowlyfe_customz]

I was wondering that... I did just run Seafoam through it though so im not sure if they would be clogged or not.... If an injector wasnt firing the fuel right would that resort in a missfire... Oh wait... that would resort in a dead cylinder right? Could be firing, but with no fuel it wouldnt combust and fire right?

 

[lowlyfe_customz]

Hahnsb2.. Yes it is the plastic intake... I have seen some pics of metal looking intakes from the factory.... If Ford did make them would it be the same as the composite I have? I really dont like the composite intake because of that same reason... Vacuum leaks, Cracking, etc... If that metal one would fit, I wouldnt mind swapping over to it.....

 

[06RangerXLT]

are you the original owner?

 

[lowlyfe_customz]

are you the original owner?

No.... I am not the original owner... I bought the truck in June of 2004 after I graduated High School... It had a little over 72,000 miles on it and now it has a little over 150,000...

 

[lowlyfe_customz]

Ok, so a little update... There is some kind of electrical ignition lock that was installed on the truck when I bought the truck... I had unplugged the power wires that were tapped into the fuse panel a couple months ago while I was trying to diagnose another problem I was having. Turns out that module was hooked into the main harness and with it being unplugged after a few miles, it killed the engine.. It would not start, turn over or anything... I hooked the power wires back up and it started back up... I am thinking that this module is going bad and have talked to a friend of mine that is a electronics installer and he is going to take that module out for me.... I am hoping that is the cause of the problems because I cant think of anything else.... Wont be taken out till the 5th so I will update as soon as I can.

 

[Big Jim M]

Most of them

Ok, so a little update... There is some kind of electrical ignition lock that was installed on the truck when I bought the truck... I had unplugged the power wires that were tapped into the fuse panel a couple months ago while I was trying to diagnose another problem I was having. Turns out that module was hooked into the main harness and with it being unplugged after a few miles, it killed the engine.. It would not start, turn over or anything... I hooked the power wires back up and it started back up... I am thinking that this module is going bad and have talked to a friend of mine that is a electronics installer and he is going to take that module out for me.... I am hoping that is the cause of the problems because I cant think of anything else.... Wont be taken out till the 5th so I will update as soon as I can.

Most times them things have a plug that emulates a factory plug. If you follow those wires you unplugged you should find a plug plugged together with a factory plug and the original factory plug lying next to it UNPLUGGED! Just take the plugged one out and reinstall the factory plug and you should be good to go..
The last ones I unplugged were in the steeering column of a rice burner..
Big JIm

 

[lowlyfe_customz]

Yeah, Ive seen a few of them that have just split a factory connection and created a jumper for the module... This one, unfortunately is different... it is actually spliced in... I had one wire come off a while back where a splice connector came off the wire and killed the ignition....

 

[lowlyfe_customz]

Ok, sorry I didnt get back for the update like I said... I had it taken out on friday as planned.... Above is a pic of what it was after the guy got it taken out.... 4 of the wires were terminated into a ground.... 2 of them were spliced into the starter under the dash, and the small wires were tapped into the fuse box to power the LED.... Im not really sure if that was the problem or not, but the truck seems to be running right now.... The only problem im having now is my ABS Light and the E Brake Light are coming on now... I was told the abs sensor could be dirty and that I could clean it and see if that fixes the problem and im not sure what to do with the e brake light coming on now.... Im off the next two days so I will look into it....