Misfiring cylinder

[lucas200400]

Hi there I have a 2000 Ranger 3.0 Flex engine with a M/T and over 135,000 miles. For the last year or so since I bought the vehicle I have been having a misfire on my #6 cylinder. It will come and go every few weeks. Typically stays for about 2 days with the check engine light and then will disappear for a week of 2.

So far I have replaced the plugs with stock Motorcraft ones and put Standard Ignition wires to replace the ones on it. Then I replaced the coil with one from Standard Ignition. After that I replaced the fuel filter, moved fuel injectors, got a professional fuel system cleaning done where they bypass the pump. There are also new O2 sensor. I have cleaned the MAF sensor along with cleaning the plenium chamber with Seafoam while the truck was running along with cleaning the intake chamber with a teflon safe cleaner. I have also been keeping up with tune ups. Also to my knowledge it has yet to overheat.

Does anyone have any recommendations as to what to do next or what to check. Also is there anyone having a similar issue to mine?

 

[bikerboy]

there are three things you need in a cylinder. spark, fuel, and compression. are you getting spark? even though you replaced the plugs, wires, and coil pack doesnt mean it's sending spark to the cylinder. do a compression check on all the cylinders and post your readings

 

[lucas200400]

I have spark to all my cylinders, but I will do a compression check soon.

 

[snake]

Could be the PCM as well- there is a place in houston that can check it for you if you can be without the truck a few days. Fedex it in and they'll fedex it back to you. They repair them too if there turns out to be something wrong with it.

 

[Yank]

Can you give an address for this place in Houston that fixes PCM's? That would be a good thing to have. Can't they "flash" the computer to refresh it?

 

[snake]

I believe they can do all that and more... www.ecmtogo.com 1-888-326-8646 I bookmarked it for future reference myself...

 

[Dead Ranger]

i went round and round with same problem looking for an easy fix. finally went and got dirty and found a bent valve. check compression, pull the plug, crank the motor and look for spark. fuel is a little harder, cuz #6 is buried under the intake, but if you do go that far, ill tell ya its easy to drop crap down into the valve chamber when you pull the injector (course, that's how i found the bent valve) so clean round the injectors. check compression. i didnt cuz i was too cheep to buy a new compression gauge.

 

[stiluv]

i had the same problem in my 99 flexfuel. it was the fuel pump and its not cheep. i spent $500 on a new one and thats with the discount through my shop. hook a fuel pressure gauge to it. good luck

 

[fixizin]

i had the same problem in my 99 flexfuel. it was the fuel pump and its not cheep. i spent $500 on a new one and thats with the discount through my shop. hook a fuel pressure gauge to it. good luck

A fuel pump can cause a misfire on just one jug, the same one all the time? That's scary. Well, I guess if that one injector was dicey/clogged, it would fail first as pressure got sketchy...

PS: Did you drop the tank or remove the bed to swap the FP???

 

[WNY964x4]

i had a 90 with a 2.9 that i dropped the tank on , it was a PITA , when we worked on my teachers truck in class , i had gotten good with removing the bed , I had the bed off , the pump changed , and the bed back on in about an hour.

 

[fixizin]

i had a 90 with a 2.9 that i dropped the tank on , it was a PITA , when we worked on my teachers truck in class , i had gotten good with removing the bed , I had the bed off , the pump changed , and the bed back on in about an hour.

Thanks for the real world feedback. I think my sender is going bad. I'm thinking removing the bed is what, 6 bolts, the tail lights harness, and the fuel filler tube? Oh, and buddy to help hoist.

Good time to replace bed-to-frame bushings, and that aged fuel filler hose... hope this isn't a thread hijacking... lol.

 

[almostclueless]

Yes, one cylinder can suffer first from a weak pump now that they've gotten the idea in their head that returnless EFI systems are a good idea. One cylinder can be the last to get fuel.


Don't throw parts at it, if the tests you can do dont identify the sure cause pay a good shop to diagnose it.

 

[fixizin]

Yes, one cylinder can suffer first from a weak pump now that they've gotten the idea in their head that returnless EFI systems are a good idea.

??? Which Ranger uses a returnLESS EFI system? My petrol is doing laps all the time, after a quick stop at the pressure regulator...