engine backfire 93 2.3

[jimbean]

This has been doing this for about a month now
At idle and slow take off

Added 4 cans of dry gas in the last 2 weeks
Replaced plug wires because of sparks 5 days ago
Triple checked wires to plugs for correct connections
Replaced fuel filter 3 days ago

Ran a code scanner today after clearing a 116 and a mass airflow sensor code
Got no codes after 2 mile test drive
Also last night i pulled the battery connectors and the {ecm connector}, after the battery so no shorts to ecm

When i put code reader on ranger the temperture guage works when i run koer tests

Still runs rought at idle

I have about 60,000 miles on plugs so i am going to change soon but i pulled them and they are all getting spark from coils and they are tan to grey in uniform color {all plugs}

During the warmup before the testdrive my temperture gauge worked right for the first time in 7 years

I also am still playing with the number 4 plug wire on drivers side just to make sure it seated so i left it off during the warmup
After i hooked up the number 4 wire the temperture dropped down to where it was before

I sprayed carb cleaner and compressed air in the temp gauge connection in the motor compartment and the ecm connection { with battery diconnected}

I have alot of corrosion on alot of engine connection
and have been cleaning all that i have seen for last year

Another question? if i pull the vaccum line off of the egr canister should there be a lot of vaccum i dont feel anything from the cannister or the vaccum line

Still runs rough at idle but not when high revs

Right now i am going to take it for another test drive with engine cold and will post back in 40 miutes or so mom`s cooking bacon and eggs

 

[jimbean]

still doing it at low revs and temperture guage is back where it was for the last 7 years
got plenty of heat in cab

 

[Mark_88]

Well, sounds like you've been through the mill on this one...but I didn't see any specs on year...and I would have to assume that it is an 8 plug fuel injected...

Backfire is usually caused by timing being off...and, depending on the year of your truck, there may be sensors that adjust the timing that need to be cleaned before it will wokright...could also be a bad ground wire on the IAC, but that may or may not cause backfire...

Fuel mixture (too rich) can also cause backfire but, again, depending on your particular setup you may or may not be able to make adjustments...

Now, a vac leak can throw off the timing causing the whole thing to be out (as I just recently discovered on my own truck) so give that a shot to find any loose or broken vac lines...

As for the evap cannister, I don't think there should be any vac on those lines...the one coming from the engine may be pressurized or it may (as on my carb) just be an overflow and then the draw from the gas tank (when sealed properly by a working gas cap) should pull it back to the tank...you may, under ideal circimstances, feel some vac on the cannister lines, but they will be from the pressure in the tank (I would think) ...

 

[jimbean]

thanks for suggestions
i will keep looking at lines
put pluggs in about an hour ago and still no difference gap 045

it a 2.3 fuel injection eight plugs
standard trans and no power anything {brakes and steering}

 

[Earl43P]

It sounds like you have two problems.

116 is the computer's coolant temp sender, has two wires and a connector.
If you got that code, I'd replace that sensor. It has a large effect on the air fuel mixture.
Read this: http://fordfuelinjection.com/?p=28

Coolant temp gage sensor uses the single wire plug. Dirt cheap part, another $8.
http://www.rockauto.com/catalog/moreinfo.php?pk=44936


If I understood you correctly, you ran it for some period with a bad #4 spark plug wire AND during that time the temp on the gage read a more normal temp, which it hasn't done in 7 years.

Sounds like you have a bad thermostat and while it was misfiring, it ran hotter and the gage showed that. A thermostat is what, $8? Change that, flush the coolant and add new, mixed with distilled water. If you want to confirm that, put some cardboard over much of the radiator and drive a normal warm up distance and watch the gage. If it warms up quicker, you know the thermostat is sticking open.

You also had a MAF code, which you said you cleared. The bad part of resetting the computer is that when it powers back up, it looks at each sensor's value and works with that, even if it is bad. http://fordfuelinjection.com/?p=10

I suggest you at least CLEAN your MAF with the proper cleaner and then reset the computer (disconnect Bat- and turn on the headlights). http://www.therangerstation.com/tech_library/CleanMAF.html

So you need a new T-stat, coolant, coolant temp sensor (as shown in the link) and MAF cleaner. Roughly $35.

Another thing to check is that the intake tube from the MAF/airbox to the throttle body is properly connected and has no leaks. If it's loose, that could affect the MAF signal.

If you still have issues after all that, we can chase after other causes like the fuel pressure regulator. Basically, when at idle, you remove the vacuum line from the FPR and the rpm should surge and run differently. If that doesn't happen, yours is bad. You can also disconnect that vaccum line with engine off and see if you see/smell gas in it. If so, it is bad. That could get more expensive, ~$25.

http://www.rockauto.com/catalog/moreinfo.php?pk=1111381
http://www.rockauto.com/catalog/moreinfo.php?pk=939963

 

[Bryan22]

One thing to take into consideration is the computer will throw a 116 code during a KOER test if the motor is not up to operating temp. If you start the truck and run a test on it cold, it will throw a 116 everytime.

 

[jimbean]

ok today i pulled injector wires
2,3,4 made the motor run really rough
injector 1 barely made a difference
would that be a fuel pressure problem?
just that number 1 injector is the first on the rail
i wouldnt think that it was pressure related
any suggestions would be great

 

[Earl43P]

Clean it...replace it...relocate it to confirm it's bad?

http://fordfuelinjection.com/?p=82

 

[jimbean]

thankyou will move it this week
how do you clean injector by hand
already use gas tank additive

 

[Bryan22]

I just solved a rough idle/backfire issue myself. Turned out to be a border-line bad coil pack. take a multimeter and test primary resistance from the electrical connector. from either outside terminal to the center terminal should be less than 5 ohms. then test secondary resistance on coil packs between corresponding cylinders (1,4 and 2,3). Should be anywhere from 10k-15k ohms depending on what brand coil packs you're running.

The secondary resistance on one of my packs was 30k ohms and it was bad enough to miss at idle and backfire pretty much whenever it felt like it. But it still ran fine at normal driving rpms.

 

[jimbean]

i move injector to new hole so i changed 1 and 4, 4 runs great in the number 1 hole and the number 1 injector runs not in 4 hole
and i am going to try and clean the spades on the injector if that doesn`t work
then im going to buy another injector
thanks for all the imput dont like to type so i bid you all farewell