Intermittent Fuel Injection (?) problem

[AngusandAggie]

Related to thread about fuel injectors, Re: yodawill2000, et al. Troubleshooting 94 J30T Gold, 195,000 miles. Relatively sudden onset of dramatically reduced gas mileage and drivability issues while owner driving car cross-country. Clearly running way rich. Finished trip by trailering car to destination. Local mechanic found hydrostatic lock in #5 and #6. All plugs (NGK PFR 6 B-11) were very sooty, and oil contaminated with fuel. Error codes for coolant temp and fuel temp sensors. After clearing lock, car started normally, driven about 15 miles, and a few subsequent short trips and idling. No problems, quick/normal starts, no black smoke from tailpipe. Next attempt to drive yielded no crank, hydrostatic lock in #5, and seemingly some excess fuel in #6. Plugs all look the same- very light soot, mainly rust red deposits. Compression pressure within all cylinders within spec. Injectors had been replaced by previous owner at about 170,000 miles. current owner has used octane additives to help out locally available 91 octane gasoline. Before time/expense of injector replacement: is something being overlooked? Intermittancy is troubling. Your comments are appreciated.

[yodawill2000]

Wow..
Sounds like either leaky lower O rings or the injectors are staying open.
Be CAREFUL as a crank attempt with Hydrolock can damage the valve-train.

I suppose there's also a chance that coolant temp issue is causing way rich fuel condition.
the coolant sensor is very easy to replace.



And
to Nico !!!

[AngusandAggie]

Thanks yodawill2000 for your response. Agree with comments on hydrostatic lock- - ongoing concern about potentially doing (serious) internal engine damage. No sign of problem after (2) lock episodes, but maybe pushing luck. Will continue to appraise problem. Thanks again for your response.

[swimshark]

replace the coolant temp sensor and fuel temp sensor. it will cause the car to run extremely rich. when my ect went out the car felt like i was pulling a train of cars up to 3k rpm and then would finally accelerate normally.

[AngusandAggie]

Thanks swimshark for comments. Was sensor replacement a total cure? Any sign of fuel contamination in the oil? Have replacement sensors on hand as next step. Still concerned that enrichment to the extent of hydrostatic lock might (?) imply lack/loss of control of injector(s)--- intermittent loss of electronic control ? Thanks again.

[yodawill2000]

You can smell the oil on the dip stick and detect if its contaminated with fuel. But as soon as it reaches temp the fuel evaporates off.
But until then it can score bearings.
When I had a leaky o ring years back i changed the oil 4 times in one week !!

[AngusandAggie]

Thanks yodawill2000 for adding more of your experiences. Due to lingering possibility of various types of internal engine damage, car is not being driven until course of action clarifies.

[yodawill2000]

You sir have a well versed vocabulary !!
Let us know your conclusion.

[AngusandAggie]

It will be my pleasure to post the eventual resolution of this problem. In the meantime, interactions with members such as yodawill2000 and swimshark provide valuable perspectives. Thanks for the compliment.

[AngusandAggie]

Continuing a thread started in July '12, re: 1994 Infiniti J30T Gold fuel injection problem. Hope that this post reaches swimshark and yodawill2000 for comment. OK, so life's an adventure. Sometimes the adventure is loads 'o fun. Sometimes the adventure turns south, and becomes an ordeal. Onset of illness in fall-winter2012 has moved my adventure towards the ordeal end of the scale, has slowed the fun portion to a trickle, and has thrown a monkey wrench into future planning. To summarize 2012 work: replaced fuel and coolant temp sensors; had injectors removed and cleaned/evaluated by InjectorRx of houston TX (no problems found. Good service--car was noticeably more responsive after injector cleaning); service records commonly mention error code 32, and the metal pipes leading to the EGR valve were both plugged to a depth of 4"; and an interesting observation-- the fuel tank was almost always pressurized (seems abnormal). Hydrostatic lock has not occurred since injector work was completed, but have only done about (6) starts and very little road time. Not gonna stick the neck way out and claim that the hydrostatic lock problem is solved. No apparent damage from the hydrostatic lock episodes. Quick starts, idle turns rough as car warms, a bit of hesitation around 2000 rpm that you can push through with a leading throttle. Anyway, resolution of health problems ain't happening anytime soon, so will put the car up for sale--- preferable to just letting it sit, and morally irresponsible to part out. Comments from yodawill2000 or swimshark, or other interested party? So I am now akin to the Blue Rajah, appealing to the Sphinx for guidance in the "darkest hour". The worldly Sphinx replied (paraphrase): "you must be more like the wolf-pack, and less like the 6-pack". Seems to fit the situation, but it may take more interpretation to know why. Thanks.

[EriCCirE]

I like this guy.

[AngusandAggie]

Thanks EriCCirE, for the comment. Love them palindromes!