Hello. My first post here. Could someone offer some advice on my next plan of attack on my # 4 cyl intermittant fuel injector problem. It reads
different resistance each time I check it. All others are at 0.0 . I believe
this stemmed from getting about 1 quart of 2 cycle fuel mix from a gas can at the end of Nov. ( I know, not too bright ). I have tried inj cleaner
with little positive results. ( added Lucas to tank that is ). It's been almost 2 months now and it comes and goes setting off 2 codes. 1 for
misfire cyl # 4. 1 for bank 1 ( I believe was obd code 307 ). In my Hanes
Service manual it states that each engine is different for the way to
clean the injector. Or, am I looking at replacing it ( or all ) of them.
I have not changed the fuel filter out since doing this mainly because I'm
not sure if it could have trapped some of the 2 cycle oil within itself.
This problem will come and go on a daily basis. Sometimes right off the
start, sometimes after 3 or more hours of "problem free" running.
Any suggestions would be appreciated.
Thanks,
Kevin

 

How much oil was in the 1 quart?

The ohm reading of the injectors is supposed to be 13.8 ohm at 68F with plug disconnected.

Toyota "T" splices into the hose coming off the filter and injects Techron injector cleaner.

 

Thank you for the reply,

There was 2 oz of mix to the quart of fuel. Originally the gallon had 8oz of
2 cycle mix added to it.

I didn't have a place to get rid of it so, down the hatch it went. It was
fresh ( for what that was worth ). There never was any smoke.
I also did this with a full tank of fuel. I have since gone through at least
60 gallons of gas.

I don't understand the ohm situation myself. With the injectors disconnected cyl 2 and 6 had a reading of 0.0 ( and run fine )

Cyl # 4 read up and down each time I placed the ohmmeter leads on the
connector. I tested them several times with the same results ?
I didn't write down the reading but they went from 4 to 6 ohms. If I remember correctly.

Kevin C.

 

8 oz of oil in around 14 gallons of gas should not normally cause a problem. 2-stroke oil is designed to burn in cylinders plus lube the various engine parts such as bearings, cylinder walls, etc.

Sea Foam is mostly mineral oil.

You are testing the injector only with the electrical plug disconnected (and not testing the harness plug terminals)?

The code should be P0304. 4 being the No 4 cylinder-if some other code post back.

This code can be caused by a lot of issues beside injectors such as ign wiring, plugs, MAF, EGR, fuel pressure, timing even the computers coolant temp sensor.

Have you inspected the spark plugs? Given oil was in the gas this is the first place to look.

The fact that the injector ohm reading on the No 4 injector varies all over the place has me wondering. Not an expert on injectors but have seen this with other electrical parts that were supposed to have a fixed ohm reading. These parts were bad or caused problems.

If the other injectors work OK would forget about the low ohms readings for now. If they work OK that is all that matters for now.

The AutoZone website has info on the injection system at the link below:

http://www.autozone.com/az/cds/en_us...rInfoPages.htm

Suggest you check the spark plugs, then ign wire for No 4 plug. Try spraying a film of water via a bottle sprayer and determine if this causes a misfire.

Would then consider the No 4 injector at this time due to the variation in ohm reading. Make sure the injector terminals are clean and some how some material is not built up causing the variation in ohm reading.

The oil might have caused injector blockage but doubt it. Not sure the oil would have effected the resistance of the injector either.

Would be looking at the plugs were oil will effect their operation.

 

Back with some new results.

I couldn't understand the OHM issue so I went back to the test this morning and got the following results. In addition, the car started fine,
ran strong, sputtered 1/2 hr later after leaving a local store, this was on
restart. It lasted about 2 minutes then ran fine once again. So here are
my resistance volts.

Cyl # 2 15.2 ohms Cyl # 4 140 OHMS (1st reading ) 70 OHMS ( 2nd reading ) 65 OHMS (3rd reading ) Cyl # 6 15.4 OHMS
{ I turned off the engine & restarted before the readings on Cyl # 4}
So, it definately appears to be the injector here . Even with these readings, I still did not have the misfire while taking these readings.

(As a reminder )
The misfire comes and goes at no particular time and lasts for a few minutes to 20 minutes or more.

Shall I try to use a good manifold injection cleaner, have it done, replace
the injector . Or some other suggestion.

As you can imagine, I'm trying to avoid the dealer & my regular mechanic
unless I throw in the towel here. ( which I seldom do )

Thank You...
Kevin

 

Take the readings with the engine off and the injector electrical plug removed. You want the resistance of only the injector.

 

Thanks for the reply once again Joey,

The engine was off when I took this reading and all three readings on
Cyl # 4 .

Engine off / Plug removed. The reading is right from the two small

prongs inside the injector. ( Gray connector removed ).

Those results were as accurate as I could get off my digital multimeter
Set on 200 OHMS scale.

Kevin C.

 

FSM for 95 1MZ-FE injectors gives resistance as 13.8 oms at 68F but also gives range of 5-23 ohm at 68F. Small amount of 2 cycle oil in tank will not cause injector to malfunction, maybe spark plug though. Cleaning the injectors will not improve the resistance. There is no DTC code 307. Misfire on #4 is DTC PO304. Change the injector.

 

If the ohm reading is all over the place on No 4 you may have found the problem.

 

Ok, I guess that settles it. I thought that cleaning the injector would
stop the fluctuation of ohms while solving the problem at hand.

I had figured that the internal "needle" or pintle was in different positions
giving me different readings.

So I take it, it is probably the internal coil which is shot.

Now, next is finding a new one. I've seen prices from $ 95.00 to $ 195.00
for a single injector. Then again, a used one on ebay for $ 11.95

I will take all your suggestions on this one. As I know little about the
internal workings of the injector. Should I bite the bullet and buy new or
take the chance on one out of a wreck.

Regards,
Kevin..