89 dodge b250 problem running possible fuel injector?

New parts :

spark plugs, rotor+cap air filter....


my van has only 83k miles on it. It mostly sits i drive it around 3k-5k miles a year.

A problem developed, and it developed after i put fuel injector cleaner in the gas tank.

Now this problem is confusing so I will try to be clear.


It ran poorly especially when cold. It would start and for a minute it ran very lopsided and shaking, and then it would run fine although ocassionally it would have a surge problem and it got really bad gas mileage ( around 8 mpg)

Then one day, the bad running became 'permanent' when i was driving it up a hill. It just wouldnt go up, I had to back it down and limp home. Its top speed was around 20 mph.

I took the air filter off and looked at the tbi injectors. Sure enough one was not firing at all, or only once in a while although it shot gas at start up always but then immediately stopped.

error code 52 was present which says oxygen sensor detects lean mixture ( this says possible fuel injector is clogged no kidding none is a lean mixture)

So using logic and not having a fuel pressure guage I figured that beacuase both injectors hook to the same fuel pressure regulator that one must be clogged if the other works fine. So I bought a new injector.

BUT when i went to replace it what i did was just switch the injectors to see if anything changed or it was possibly electrical. BOOM, the van runs great instantly. I can see the injector that was completely clogged doesnt spray perfect but it works fine. just moving it for some reason. So I returned the part.

A week later suddenly it has gone back to symptom one again, it runs terribly and surges until its been running for a few minutes, and then it runs mostly ok with occasional surges once in a while stalling and terrible gas mileage. occasionaly backfires through the throttle body and then right after the backfire it runs fine again.

ok could a fuel pump be the problem here? How would operating temperature affect a fuel injector? Is it just the same injector reclogging somehow?

what should I do on my own without a mechanic to figure out this problem?

New parts :

spark plugs, rotor+cap air filter....


my van has only 83k miles on it. It mostly sits i drive it around 3k-5k miles a year.

A problem developed, and it developed after i put fuel injector cleaner in the gas tank.

Now this problem is confusing so I will try to be clear.


It ran poorly especially when cold. It would start and for a minute it ran very lopsided and shaking, and then it would run fine although ocassionally it would have a surge problem and it got really bad gas mileage ( around 8 mpg)

Then one day, the bad running became 'permanent' when i was driving it up a hill. It just wouldnt go up, I had to back it down and limp home. Its top speed was around 20 mph.

I took the air filter off and looked at the tbi injectors. Sure enough one was not firing at all, or only once in a while although it shot gas at start up always but then immediately stopped.

error code 52 was present which says oxygen sensor detects lean mixture ( this says possible fuel injector is clogged no kidding none is a lean mixture)

So using logic and not having a fuel pressure guage I figured that beacuase both injectors hook to the same fuel pressure regulator that one must be clogged if the other works fine. So I bought a new injector.

BUT when i went to replace it what i did was just switch the injectors to see if anything changed or it was possibly electrical. BOOM, the van runs great instantly. I can see the injector that was completely clogged doesnt spray perfect but it works fine. just moving it for some reason. So I returned the part.

A week later suddenly it has gone back to symptom one again, it runs terribly and surges until its been running for a few minutes, and then it runs mostly ok with occasional surges once in a while stalling and terrible gas mileage. occasionaly backfires through the throttle body and then right after the backfire it runs fine again.

ok could a fuel pump be the problem here? How would operating temperature affect a fuel injector? Is it just the same injector reclogging somehow?

what should I do on my own without a mechanic to figure out this problem?


This is TBI injection and you have 2 injectors. One injector may have an internal problem and need replaced. Try this, go down to NAPA/CarQuest and pickup a can of SeaFoam and run it thru your gas tank and see what happens. www.seafoamsales.com
Check the caps that snap on to the top of the injectors to make sure there is no corrosion and that the caps are making good electrical connections with the injectors. Has the fuel filter been replaced? New injectors are pretty expensive, you might want to try an online source like
www.injectors4u.com/tbi_injectors.htm
www.lincolnsonline.com/tech/00151.html

thanks for those links

I have already replaced the injector

it cost me $100 though. I wish I had seen that link earlier. I may buy the 2nd injector from there someday so I have 2 new ones to work with. Im not sure the other one is spraying correctly, it doesnt seem as full as the new one. But Im not an expert and Ill get to that later.

what the injector was doing was actually leaking up through the top and shorting out the electrical connectors. It might have done this because it was clogged? Im not sure it was weird but i opened it and it leaked straight up.

the gas was quite dirty too I noticed probably the cause of the problem, dirty gas... but Im not sure? I used a lot of fuel injector in tank things before it ceased working and I think they cleaned my fuel tank and shot that junk to the injectors. Im going to replace my fuel filter tommorow.

it was quite strange

anyhow there is a new one in there now and it fires. but im not out of the woods it seems.

now it runs really rough at start. after it warms up for a while it runs passably.

Before I replaced the injector I got error code 52 which is oxygen sensor is stuck at too rich mixture. Ok, but now I have no error codes.

However it is running bad until warmed up and getting terrible gas mileage. Do you think the oxygen sensor was killed?

I've heard of many cases where the O2 sensor stopped working and the vehicle ran rich. The same pollutants that may have clogged your injectors may have dirtied up the O2 sensor. I'd try removing and cleaning the O2 and see if that works. If not, the replacement should be less than $90 or so.

ok well the part is $42 at kragen right now, and it comes with a $10 kragen gift card.

So its reasonably cheap to replace it, and if I took it off I would want to put the new one in. So I have to meditate on it.

Its not really as easy as all that because its the heated o2 sensor kind and it comes in a rusty pipe.

So anyhow well while the injector was clogged( it was not clogged actually it was leaking and shorting the electrical connector so lets call it intermitantly dead), the engine was running too LEAN, not rich.

But the error code came up twice, as too RICH ( the error came up after it was running passably mind you, when the injector was working, not when it was not working at all.....)

Ok and now, after the injector replacement there is no error at all....but um... i replaced what was wrong and its still running poorly so I cant think of what all can cause those symptoms....

ok well the part is $42 at kragen right now, and it comes with a $10 kragen gift card.

So its reasonably cheap to replace it, and if I took it off I would want to put the new one in. So I have to meditate on it.

Its not really as easy as all that because its the heated o2 sensor kind and it comes in a rusty pipe.

So anyhow well while the injector was clogged( it was not clogged actually it was leaking and shorting the electrical connector so lets call it intermitantly dead), the engine was running too LEAN, not rich.

But the error code came up twice, as too RICH ( the error came up after it was running passably mind you, when the injector was working, not when it was not working at all.....)

Ok and now, after the injector replacement there is no error at all....but um... i replaced what was wrong and its still running poorly so I cant think of what all can cause those symptoms....

If there were fuel related problems that may have fried your new plugs, especially if you were dumping extra fuel into the engine. There is no way to clean them once they start to short out. Also check your spark plug wires, cap, rotor to make sure something wasnt knocked loose.

ok well

i looked at the spark plugs and they were indeed covered with soot. in very few miles.
All of them showed signs they were firing though. I replaced the 4 worst ones and also replaced the wires.

Ok the entire secondary ignition is brand new now other than the fact that soot is on the plugs.

It does run much stronger. I must have had some level of misfre to make a difference.

It still starts very rough. It still gets awful gas mileage I cant even calculate. if starts are included, its getting like 5 mpg....

I took it for a long run because once it warmed up it was giving a lot of power and finally after about 45 minutes error 52 came up again. oxygen sensor stuck in too rich state.

Ok well I cant think of what can cause that other than the oxygen sensor itself being bad.

It is at 83k miles about time to replace the thing anyway.

that sea foam stuff scares me. but i obviously need to clean out the combustion chamber with something now, and im not even sure im done shooting junk into it from the fuel. I hope I am...

If you're wary of Sea Foam, try a couple of tankfuls with a normal fuel injector cleaner, or STP fuel treatment or something.

Once you get the O2 sensor changed, hopefully your mileage will come up.

You can also just run the SeaFoam through the gas tank. I've used it for years and it's close to the same stuff Mother Mopar uses which is their Combustion Chamber Cleaner #4318001.

well I am still having problems...

Heh I dunno how to describe it because its changing on a regular basis. The hard starts are quite different now and much shorter, I assumed the computer was readjusting....

but now backfire is much more common.

What are the possible causes of intake backfire? I have to go through and check them off. It has a new fuel filter, can a fuel pump cause regular backfire? it can also be the unreplaced injector. can it be combustion chamber deposits? what all causes throttle body backfire?

When i replaced the fuel filter, the gas was totally clean in it and coming to and from it.... unlike the gas i got at the injectors a few weeks earlier when i replaced drivers side injector. That was dirty. So I assume Ive run through the pollutants but I cant trust my own logic on this problem because I still cant figure it out....

Well I have 2 bottles of slick 50 fuel system cleaner Im going to use up ( as soon as I can afford all the gas lol $3 a gallon over here in northern cal) And then i will use sea foam


This van is my 2nd vehicle my main trans is my geo metro. But it is my baby.

Ok I have a shaking problem some sort of rattle.... It only comes up when drive in engaged, not in park.... It seems to be coming from the alternator ok but its engine related, the vibration is coming from the engine it just so happens that is the loosest peice of metal attached to it. Some sort of fuel unblanced running problem. It goes away when its fully warmed up.... ok well Im confused.

I guess oxygen sensor next and see if this goes away. also one thing of slick 50 and 10 gallons go in tonight
u two guys, what would you do next? no errors this week on only short little runs.

ok last night i put in the injector cleaner and 10 gallons.

i took a 15 mile freeway trip. I got good ol error 52 again. Perhaps it takes about 15 miles of running to register an error code im learning this

turned it off for a few hours. it started up fine. same 15 mile trip no error code.


This morning for the first time in weeks, it started fine. Nothing wrong.

one part of my head is saying its the oxygen sensor ok.... But how could it get better?
the other part now says that its actually the injector I didnt replace. There is something weird I am learning about injector operation, because although they seem simple they are strange, and that a 'clogging' isnt really what happens, I mean the holes stay open, whats going on is the carbon gums up the movement of the internal float. operation of one seems to make the ecu turn off the other one not moving correctly, or if not that it just stops on its own, I mean if it gets a signal to open, and it doesnt open fast enough for the signal it just closes.

anyhow, weird stuff I have to learn more about it.

and the third part of my head just thinks that the fuel pump is dying and only gives problems at start up. Like the sock is clogged... inocorrect pressure is reaching the injectors its just that one is new so it is getting the full shot where the other is blocked so its getting less ( doesnt quite make sense to me but as I said they are weird)

there's a similar post about a similar problem.

It seems like an injector drive problem from the ECM.

That's what it was on my 89.