Turbo Dodge Forums banner
1 - 12 of 12 Posts

·
Registered
Joined
·
1,165 Posts
Discussion Starter · #1 ·
Hey all,

After rebuilding my engine I've noticed I'm still getting fuel diluted oil. My oil only has about 100 miles on it and the dipstick already has a gassy smell.

I'll be doing some diagnostics, but I have a hunch it's the stock injectors sticking open, or leaking fuel after shutdown while the system is still pressurized.

I know there was a shop that services and flow tests injectors at a decent cost (compared to buying new) people have used here before.

If I do need to get my injectors serviced, I'd like to already have a lead on who to use.

Does anyone have the name of a reputable business who does injector cleaning/servicing? Thanks!!

-Zach
 

·
Registered
1992 dodge shadow es turbo
Joined
·
861 Posts
Search for a local diesel injection shop, they can probably help you out, that’s who does it around my area. FWD performance does them I believe but probably not worth the shipping costs for stock injectors
 

·
Registered
Joined
·
2,573 Posts
 

·
Administrator
Joined
·
25,735 Posts
There are three ways to tell if you have leaking/stuck open injectors creating a rich, fouled spark plug condition.
(Assuming there is no fuel in the FPR vacuum/pressure line.)

1)Connect a fuel pressure gauge, check all fuel pressure readings to be sure pressure is correct.
a)Start the engine, verify fuel pressure and then shut the engine off, does pressure hold or drop quickly?
(dropping slowly over 15-20 minutes is normal)
2)Remove the fuel rail and injectors, keep the fuel line connected and turn the key on or manually actuate the ASD Relay to pressurize the fuel rail, look for fuel leaking from the injectors.
3)Run an Injector Balance Test, this will tell you if all injectors are flowing the same amount of fuel.
a)Connect a fuel pressure gauge, turn the key on to pressurize the fuel rail (be sure to pressurize the fuel rail after testing each injector so pressure is the same for all cylinders being tested.
b)Using an injector pulse tester, pulse the injector and record the pressure drop on each cylinder.
4)If you have an injector that is not flowing as much as the others the injectors need to be directly chemically cleaned.
This is what we have...

Fuel/Oil/Trans/Coolant Additives are IMO..."Snake Oil".
 

·
Registered
Joined
·
1,165 Posts
Discussion Starter · #5 ·
Thanks for the thorough reply as always, Jan! I'm planning on tackling this project over the weekend. I don't get much time during the week for tinkering.

Was able to get my wideband A/F gauge all hooked up and those numbers seem acceptable so far, so I'll certainly need to go through your diagnostics to learn more.

Here are my A/F findings:

Half throttle boost - between 14.2-15.5; usually staying around 14.7

Full throttle boost - between 10-10.5 - higher gear flooring it hangs around 10 even.

Idle at operating temp - 14.5-15.5

Slight throttle boost can hang around the 15s, is this a concern for being too lean while boosting?
 

·
Registered
Joined
·
671 Posts
Hey all,

After rebuilding my engine I've noticed I'm still getting fuel diluted oil. My oil only has about 100 miles on it and the dipstick already has a gassy smell.

I'll be doing some diagnostics, but I have a hunch it's the stock injectors sticking open, or leaking fuel after shutdown while the system is still pressurized.

I know there was a shop that services and flow tests injectors at a decent cost (compared to buying new) people have used here before.

If I do need to get my injectors serviced, I'd like to already have a lead on who to use.

Does anyone have the name of a reputable business who does injector cleaning/servicing? Thanks!!

-Zach
I have used this service several times with very positive results:
"Ultrasonic Fuel Injector Cleaning Service 6 Cylinder Includes O-rings And Seals"
For both for my V6 LeBaron and V6 Liberty.
I wouldn't hesitate to recommend. You pay for, then send, then receive back very quickly.
Best wishes - Andy (Omnibus)
 

·
Registered
Joined
·
1,165 Posts
Discussion Starter · #7 ·
Thanks for the injector cleaning service suggestions. I'm logging them as possible choices going forward. For this time around, however, I've decided to give Mr. Injector a try after running through the diagnostics Jan has posted. All these services seem to use the same process of cleaning. I've heard from multiple others that Mr. Injector does excellent work, so here's to hoping it's true.

I figure even if I don't have a leaking injector, these things are 32 years old and I'm sure it wouldn't hurt to have them professionally gone through.
 

·
Administrator
Joined
·
25,735 Posts
I am not sure about your "slight throttle and half throttle boost" readings, they do seem lean for any amount of boost.
Is this car all stock?
Do the spark plugs show any signs of fouling?
Do you have access to a scanner?

Assuming all basics are correct for Cam/Ignition Timing...
Rich/Lean could be a fuel pressure issue, a MAP Sensor Calibration issue, a TPS Calibration issue, CTS Calibration issue, etc.

TPS
1)Backprobe the Signal and Signal Return Lines of the TPS connector.
2)Connect a digital voltmeter.
3)With the key on/engine off (KOEO)
a)Closed throttle voltage should be in the .30 -.90 range.
b)While watching the voltmeter slowing open the throttle, voltage should increase smoothly and consistently with no drop-offs or spikes in voltage.
c)WOT = Any voltage above 3.50.

CTS
1)Backprobe the CTS connector
2)Connect a digital voltmeter
3)Start the car and watch CTS voltage which translates to an actual temp.
Motor vehicle Automotive tire Automotive exterior Automotive design Coil
Handwriting Font Material property Parallel Rectangle



 

·
Registered
Joined
·
1,165 Posts
Discussion Starter · #9 ·
Looks like I have more homework! Lol

I have a scanner but haven't tested it yet to make sure it works.

I haven't pulled my plugs out yet but will inspect this weekend.

Timing I'm pretty sure is good, it didn't seem like I made any mistakes there and I'm pulling about 20" of vacuum on idle.

As far as modifications, I'm running a Stage III cal from FWD, and the exhaust had been opened to straight through 2.5".

The head and manifolds are mildly ported and polished, along with a 3 angle valve job and a TBI cam with the conical spring mod.

Since this build is still fresh I have a manifold vacuum/boost source routed directly to the wastegate so I'm only making about 4psi of boost at this time.

My theory on the lean readings was that the engine is still running in closed loop at partial throttle and low boost, so it would try to keep the A/F at 14.7 as much as possible.

While WOT seems a bit rich, I expect that to lean out when I turn up the boost since the cal was designed to run at 15psi.

Maybe I'm way off base on all of this, I'm not a professional and always looking to learn more.
 

·
Administrator
Joined
·
25,735 Posts
Your scanner can be used to view all sensor readings, injector pulse width and knock retard.
Just remember that the baud rate on the scanner/controller is 1.25 seconds so data is not actually live.
(KOEO Map Voltage = Actual Barometric Pressure, be sure it is correct.)

There are lots of videos on YouTube regarding A/F Ratio under boost and more info on Google, who knows, maybe you will find some info that sheds some light on your issue.
 

·
Registered
Joined
·
1,165 Posts
Discussion Starter · #11 ·
Your scanner can be used to view all sensor readings, injector pulse width and knock retard.
Just remember that the baud rate on the scanner/controller is 1.25 seconds so data is not actually live.
(KOEO Map Voltage = Actual Barometric Pressure, be sure it is correct.)

There are lots of videos on YouTube regarding A/F Ratio under boost and more info on Google, who knows, maybe you will find some info that sheds some light on your issue.
Thanks, Jan. I'll see if I can get the scanner working, and if not, I can always do it the back probe way.

I've been researching as much as I can on A/F under boost. Most of what I've come up with so far is yes, I should have a richer mixture in partial throttle (in a perfect world), say about 12.5 - 13. However, for our cars specifically it seems that the computer won't really richen things up until you hit open loop operation.

Do you run a wideband? And if so what are your findings on partial throttle boost around the 4-5 psi range?
 

·
Administrator
Joined
·
25,735 Posts
No, I do not have a Wideband, car is all stock.
 
1 - 12 of 12 Posts
Top