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Comments
Cross your eyes and think green / brown.
what do you think?
robert
Perhaps you could explain it better... did you say it sounds like the snapping of electrical discharge. (sparking sound?) Perhaps an effect caused by the 8 individual ignition coils.
good luck,
robert
I am not sure what noise an injector sounds like, but my initial thoughts were that it sounded like a slight lifter tap. I would also equate it to the chatter of a "reed relay" or comparable tiny relay- not the clunking of a larger relay.
Sorry to hear that you are having to dig your way out of the snow, but do envy your ownership of a 4WD. I love the height of the 4WD and really wanted one- just found it hard to justify in southeastern Missouri.
Thanks
LL
3-4 mv at the two firewall bolts and the two fender bolts
9 -10 mv at the alternator case, mount bolt and the bolts used to hold down each sparkplug coil assy.
What do you think??
I noticed something odd however- Two of the plug coils have what appear to be capacitors mounted to the bolt. They are connected at one end only through the metal grounding tang.
There is a similar module at the Passenger fender bolt connecting ground to a wire which comes out of the 1 1/4" wiring harnesss by the accumulator. The part number is:
56041396AA
250-0.47 (probably 250 volt .47 microfarad)
2119 (probably julian date and year of mfg)
In this application, the capacitor would be shunting any voltage spike to ground, not DC levels. The 2 units at the plug coils serve little value if connected at only one end. I have never seen a capacitor connected at only one end, even up through lower RF signals. Besides, a .47 microfarad is for a signal well below the RF level.
The two "capacitor like" units at the plug coils differ only in the last 4 digits (1969 vs 2119), which is why I suspect it to be date of mfg)
Are you willing to check yours? If so, they are located on each side of the engine- 2nd plug back. Specifically they are the #3 (drivers side) and #4 (passenger side) plugs
Ed
Ed
All of your voltage measurements appear well within acceptable levels. (Remember, a LOWER reading means a better connection)
I was going to ask you about the injector capacitors next but you beat me to the discussion.
The schematic wiring diagrams clearly show that each bank of injectors has a capacitor on the +12V side of the circuit. As you allude to, these are known as decoupling capacitors. (Decoupling is their function, not the type of capacitor...If anyone has further questions about this please read a good book on electronics design)
I noted that the ones on MY Dakota are likewise NOT CONNECTED INTO THE CIRCUIT. I suspect that the engine comes from the MACK build plant with them installed but the wiring harness (which comes from another plant?) has the connectors missing for some reason.
What is the purpose of the capacitors? Well... the function of the caps are to "store" energy and release it as needed. ...."lot of technical stuff missing here" This would help the injectors open faster when the computer sends the signal to open. One could think of this as making the injectors more 'responsive' or 'snappy' when they open.
What happens when the caps are not in the ckt? Decoupling caps can usually be removed from any ckt with no apparent operational differences.
HOWEVER... it must be considered that the designers SPECIFIED that the caps should be there.
a newer stlye 2WD Dakota. I need to sell them
asap. My truck is a lease and I need to turn it
back in. The body will fit on a 4 wheel drive reg. cab also. The suspension lift is by fabtech.
email me at matthew.goss@gm.com with any questions. My asking price is $100.00 for the body lift (complete) and $175.00 for the suspension (with shocks)
I live in GA, had a yellow slime, rather than buildup. Switched to Synthetic at 2,200 miles and have had no trace of yellow stuff since.
If you live where it's colder, you'll get condensation built up. Something about it not breathing like other engines; I'm not a chemist, but I can believe that part.
I've got to look into the synthetic oil brands. I was chastised a bit on here for using Mobil 1. Used the darn stuff for 15 years or so and nothings ever blown up! Synthetic is superior stuff for many reason, any one with a good reason to switch, please let me know. I have no Mobil or Exxon stock!
Good luck out there.
I guess the argument is do you buy Yugo or recognised make if you are only keeping the car for a few hundred miles - Yugo is probably good enough and cheap - others are better. As far as I am concerned to each his own. My personal choice would be to always use synthetic, in my case Mobil 1. Having said that, I am in the process of buying a car that I will put sufficient miles on to change the oil every 8-10 weeks. As it has a capacity of 11 quarts of oil that natural stuff is starting to look VERY attractive.
I paid 24,900 including everyhting except taxes. Worked on 4 dealers for 2 months. I am so fraking happy. I can't wait to dump my 93 Pathfinder. Thanks to all you guys for asking the questions i wanted to and answering them like i wanted. There are no dumb questions here! Party on Dakota dudes!!!!!!!!!!!!!!!!!!!!
You did say that the print had the cap connected to the 12 volt bus of the injector bank at each side. Is that same 12 volt bus also sourcing power to the high voltage coils, or are the B+ primary side of the coils being fed from another circuit altogether? (I wish I had my manual now!!!!)
With the capacitor tied between B+ and ground, I
assume that the switching occurs on the negative side of the injector coil. Would make sense. I am not very familar with the auto injector circuitry but assume it to be similar to any similar inductive circuit.
As with any inductive load - On turnoff, the coil will act like a small reversed battery and generate a small voltage spike on the line. (with a DC circuit, this is easily observed with a scope) If not properly filtered to ground, close to the source, it could possibly create havoc with other sensitive electronic chips. HOWEVER, most of the time there is probably adequate current draw (load) on the system reducing the reflected load impedance, thus drowning out most of the spike (with or without the cap). Either way, I think we are getting close but I won't feel good till we get to the root cause of the tick.
Are you sure you don't hear the slight tick???? I would feel better if you did! Especially knowing your caps are not hooked up either.
Ed
We have 8 injectors and 8 ignition coils all inducing voltage spikes into this single power supply wire. Having the capacitors missing from this +12v supply circuit will most certainly make this electrically 'noisy'.
As you surmised, the PCM (Powertrain Control Module) [what most people refer to as the engine computer] controls ALL of these things and more by switching ground. (Standard electronic design)
NOTE: Did you know that there is a BATTERY TEMPERATURE SENSOR underneath the battery? This allows the PCM to control the Alternator and calibrate the fuel/spark for specific thermal conditions.... pretty cool design
Thanks in advance.
Scott
I think one factor that is often overlooked is the quality of the oil filter, most people will only change with their oil - the hassle factor if nothing else, and if you are 'pushing' the change intervals with a synthetic then you need to make sure the filter is up to the job.
Interesting to read the macguy's comments on using regular oil in demanding applications. The engine I was referring to earlier on is the late '80s Jaguar V12. This runs at a compression ratio of 11.5:1 (at least it did new), and yet factory still recommends a quality natural oil - Castrol in their case.
Incidentally, I saw a few comments on 10W30 oils, I believe that for most climates / applications Dodge recommends 5W30 for the 4.7.
BTW- finally figured where the water droplets were coming from. The AC accumulator!!. Driving home today (temp around 65 degerss) I noticed the AC was on. Huh!!!! I had it in the Floor/vent position (this position has no snowflake). Pulled out the owners manual again and discovered the AC MAY RUN in all non-snowflake positions EXCEPT the VENT only position. I obviously didn't catch it in the book earlier and may have overlooked some conference messages where it was being discussed. Not sure what triggers the AC unit on while in these other positions. Temp??? Wouldn't expect to see a humidity sensor but heck if we have a Battery temp monitor, you never know.
Had condensate all over the place. I think I am going to wrap that unit and the metal portion of the input/output hoses.
And on the filter change - YES - you'll get a half cup or so on you doing just a normal change by hand. But I use a neat trick - ALL OF YOU GUYS MIGHT TRY THIS: I have medium sized hands so I got a pair of the largest sized heavy rubberlike yellow dish gloves I could find. I put them on, then roll them (backwards) inside out so just my fingers are in the gloves. Then I slip the part that normally goes up my arm over the filter so that when I turn the old filter and break the seal, the overflow is caught by the cupped part of the glove, and the filter slides neatly down inside. Make SURE the oil is just warm - NOT hot or you'll burn your fingertips! Cleanup is easy... I also opened my main oil fill cap (the dreaded yellow slime tube) before I changed mine the second time (when I went back to Mobil 1), got a lot less overflow out of the filter. I'm currently tracking down availability of an adapter that lets you 'remote' your filter - also lets you add a SECOND 'INLINE' filter. I use them on my Porsches; they supposedly have one that fits the 4.7. Here's hoping...
Anyway, I am currently debating the use of synthetic in a Jaguar V12 engine. These engines don't have the best reputation for keeping oil inside and I am concerned that a switch to synthetic will cause the engine to spring leaks everywhere, for the very reasons that I would use synthetics, better lubrication, smaller molecules blah, blah, blah. This is a particular concern with a high compression engine. What is your view on this?
4WD SLT Extended Cab (Quad-owner can answer too)
3.55 Rear Axle
Tire and Handling Group
5 sp Manual
4.7L V8
Limited Slip Axle (not sure if this makes diff for this question)
I am interested in your opinion on the power (I have test driven the above combo with the 3.92). Can you start off in second gear with the 3.55? Do you feel you have to (the 3.92 has so much torque in 1st that you almost HAVE to start in second)? Can you start pretty quickly off the line? Do you feel it has the "oomph" of a V8 pickup? Also, what kind of gas mileage figures have you been getting? This is the last issue I must resolve before ordering. Towing is no problem since I do not intend on using the whole 6000lb max that is seen with the 3.92. Mainly cruising, commuting and weekend hauling. Thanks for your inputs!
I'd investigate closely the resale value before making such a purchase, while there is obviously a market, I have a feeling it's in small geographic areas of the continent.
The real duck will quack louder when you go to sell it.
Ron S.
Any confirmations about this?
The facts about the Synth oil are well documented.
- Better protection (Both cold and hot extremes)
- MUCH cleaner engine (No build-up of black scum)
- Tendancy to leak out of ANY small orfices. (Can even swell rubber seals on some engines)
- etc... etc.
But can synth oil eliminate the emulsion in a DC 4.7L OHV semi-hemi internal combustion engine?wilmar1 - Pennzoil synthetic should be fine, I just wouldn't use regular Pennzoil (too slick) w/o a good filter that has 'cold start' valve improvements... I've heard the prefill-the-filters routine for years. Actually preheating the oil with an engine block heater is probably more beneficial, though. If pre- filling the filters gives you peace of mind - knock yourself out. What you really want is an oil that has the 'clingy' or 'filmy' additives that help prevent cold-start metal to metal contact - they leave behind a film for a couple of days before gravity & other factors leave the cylinder & piston walls clean.
Bookitty
I have gone to the dealer 4 times and they say that this is a common problem, and that Chrysler is coming out with a new service bulletin to fix the problem (retard the timing)it should be out next week they said. the technician I deal with recommended using UNOCAL 92 octane only.
Does any of you guys have any noises in the right hand side, back, when turning on a drive way (right hand turns only) ???
Any comments would really be appreciated.
please post in this forum or e-mail to an310@pacbell.net
Other than those two problems I love the truck!!
I will keep you guys posted with the pinging..
thank... Ed
Ron S.
thanks...
Skipping over large bumps or "washboard" is expected but not on normal streets...
I bought a GEM flat tonneau. It's metal on both sides, comes off in about 1 minute with a buddie or wife or whomever helping. Put one of those bed extenders on it, don't really know how much it'll get used.
I think the Quad 4x4 handles like a dream. I'm moving one of my daughters next Tues with a 12x6 trailer, doesn't weigh much and not expecting any problems. 4.7 sure has the poop to do that ok.
Be careful out there; God, I wish I'd made that up originally!
Hope this helps,
Chad
thanks... 1174
I have had my quad for 1 month and put
1500 hiway miles on it. I have the indash cd player , it does great no skipping!