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Discussion Starter #21
latest update

After spending two days rebuilding the driver's seat motors, I pulled the intake today.
Light-blue injectors.
.0003 ohms max resistance on any wire in the harness including to the coil.
Put dielectric grease on all connectors I could reach, and the vacuum hoses.
Put vaselene on the intake gaskets.
Result is *slightly* better idling, still surges, and can still feel the misfire though it is softer.
 

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Discussion Starter #22
Does anyone know if the equivalent to the Ford KOKO (key on key off) test is available for these cars? It is great on my '91 SHO to diagnose individual component failures.
 

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Does anyone know if the equivalent to the Ford KOKO (key on key off) test is available for these cars? It is great on my '91 SHO to diagnose individual component failures.
"Key Dance" - without starting the engine cycle key: lock > off > on > off > on > off > on quickly and look at odometer readout until 'donE' is displayed...
 

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Discussion Starter #24
That's how I got the P0301 code...
The Ford KOKO routine:
m.youtube.com/watch?v=nl2lqqS7vvE
You jumper a port on the ODB to ground, then run key on exercises, start the car, turn the wheel quickly side-to-side, then let it idle while the computer shuts off components to test operations in real-time

When done, it will give you codes beyond the regular ones - specific injectors, spark, etc.
 

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That's how I got the P0301 code...
The Ford KOKO routine:
m.youtube.com/watch?v=nl2lqqS7vvE
You jumper a port on the ODB to ground, then run key on exercises, start the car, turn the wheel quickly side-to-side, then let it idle while the computer shuts off components to test operations in real-time

When done, it will give you codes beyond the regular ones - specific injectors, spark, etc.
If you like the "Christmas tree" tests, find a gen2 minivan...

Key dance will give you all of the "generic" OBD-II codes (including injector, spark plug, and sensor codes).

gen3 & gen4 vans use OBDII for diagnostics, for module and system specific codes you need a scan tool compatible with reading those (DRB-III was the Chrysler designed tool for this application).

The "proprietary" codes (body, transmission, ABS, SRS, etc) are only available via compatible (DRB-III compliant) scan tool.

Some components (instrument cluster, HVAC controls, etc) have built in diagnostic routines that can be activated with a 'proper' button press 'sequence'.
 

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Discussion Starter #26
While I agree the newer systems are better at self-diagnostics, any good programmer will go over their work line-by-line. That's how this diagnostic works on my SHO, like a debugger/compiler. It target tests the components one at a time then spits out the results.

Generic P0301 - Misfire Cylinder 1 (and ONLY Cyl 1). What are potential possibilities?
Spark - Replaced plugs, wires, coil, used di-electric grease on connectors. moved things around - No change. Timing light has weird results.
Fuel - Swapped injectors, tested harness, di-electric grease on connectors - No change.
Mechanical - Changed head due to burnt exhaust valve. Went with heavier oil in case a lifter wasn't pumping up. Have not tested timing chain slack.
Sensors - Dealership tested Cam and Crank sensors. I put dielectric grease on the connectors just in case. Doesn't seem to have a knock sensor.
Fuel pressure - Dealership tested this, was fine. And would impact more cylinders than one.
Vacuum leak - Dealership and I have gone over every hose, gasket, etc, cannot find a leak. Evaporative Purge Valve disconnection results in consistently rough idle. Currently, it 'surges' every two seconds.

So, as a parts-replacement effort, I have not changed:
Lifters Cyl 1
Timing Chain (Normally would be random/multiple cylinders, not just Cyl 1)
Cam/Crank sensors (Should impact more than Cyl 1)

The only other item would be something further back in the harness to the ECM - Cyl 1's actual signaling lead from the ECM to the intake harness. I have not tested that leg yet.

TankII
 

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IMHO, it's likely whoever repaired the burnt valve treated the symptom without addressing the underlying cause...

Either there's other damage in the valve-train or for whatever reason cy1 is running leaner than the rest. If timing was that far off on cyl1 to detonate with opening valve, you'd definitely feel it in engine performance (not just idling).

Heavier oil and these motors is a dicey combination - the passages for cam lubrication were not designed for thicker / more viscous oil...
 

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Heavier oil won't do much for you if the pick-up o-ring seal has failed... I know from experience. Tried heavier oil, larger filters, and over-filling the oil. Only over-filling really seemed to make a significant difference and that is because if you over-fill enough, I assume you eventually fill to the level of the pick-up tube to block/pump interface and, thereby, keep air from getting in.

Only other thing I can think of would be a worn cam lobe.
 

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Discussion Starter #29
I wish it was as simple as a worn cam lobe, but it pulls very strong and runs smooth above 1100 RPM...
 

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My van has the exact same symptoms as TankII, except mine is cylinder 3. I've done the same tests and swapped/replaced the same parts. I'll be watching this thread closely! In the meantime, I just drive her and monitor it. At long stoplights, I put the transmission in neutral to smooth things out.
 

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Discussion Starter #31
Poking around on another forum came up with a dismaying diagnosis.
As previously mentioned, camshaft wear is a known issue. However, another person found their P0306 issue was cam bearing material had lodged inside one lifter. To replace the lifters and cam requires pulling both heads, since the lifters don't come out any other way.
From experience, replacing cam bearings in a pushrod engine requires removing the plug at the end of the block - requiring an engine pull.

I'm not exactly enamored with the idea of investing this much time into the Minivan, despite it being a loaded SXT with side airbags. The transmission downshifts hard too, so I would wind up dropping the entire subframe to do the engine and tranny, only to see it continue to rust away. I would rather let the lifter suffer until something else expensive stops working or it fails emissions at this point. I'm looking at about $2400 in parts and 14 hours labor to do all of this by myself in my garage with hand tools. Taking it somewhere local (in Connecticut) would cost me three times as much.
 

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If you go through the effort, just make sure that motor oil pick-up tube o-ring seal is good so you know the new cam/bearings and lifter/lash-adjusters are getting proper lubrication and pressure... you'll know if it's a problem as you'll have upper engine valve train chatter if the o-ring is leaking air into the pump. Recommend replacing this o-ring whenever you replace the oil pan gasket... or no later than every 140,000 miles or so, which is roughly when I noticed the valve chatter on mine. Can't imagine having air in the oil supply is good for cam, cam followers, the lifters/adjusters, or, ultimately, the valves and/or valve seats over a long duration of improper adjustment...
 

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Discussion Starter #34
Growling noise solved! going for a drive to see if P0301 comes back

@tjhess74:
I poked around with a machinist friend of mine (not a mechanic at all), and he spotted the serpentine belt wiggling.
Turns out the noise was from the tensioner pulley, and the wiggle was due to a bent alternator shaft!

Going for a long drive now to see if the code comes back. It still has a rougher/surging idle than I would like, but it is better so far.
 

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Discussion Starter #35
Started it cold this AM, code came back. If time permits, I will try an oscilloscope on the ignition coil tomorrow.
 

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Discussion Starter #36
@ ScuzziOne
When I pulled the pan around 120k miles, I checked the seal, and it was still flexible. Even now, there is no valvetrain noise, though if it sits for a week you hear a slight rod knock at startup.


Always Valvoline synthetic until this last oil change.

At least now my wife is not embarrassed by the noises, and since I fixed a few other items (groaning steering, driver's seat), we will wait another year or more before getting a Pacifica. Assuming the transmission hard downshifting doesn't convert to a failure.
 

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I actually just changed my alternator a few weeks ago due to the decoupler pulley eating itself. There is no change in the engine idle post-replacement. Several months ago, I replaced the oil pan gasket and dipstick o ring. The engine was clean as a whistle and has no leaks, which is nice. I'm resolved to live with the rough idle and driver her until she can go no longer. Like yours, once off idle, she runs like a dream, so I'm hoping it's just a characteristic of this engine and doesn't hint at something more sinister.
 

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Discussion Starter #38
I'm sorry I haven't given an update, but the G.C. made it to Harrisburg PA and back, only the rough idle to contend with.
In the meantime I've been fixing up our rental house (five years of wear and tear) while working 60+ hours/week again. Nights/weekends are now overbooked...

However, I was able to fix the check engine light on our '01 Stratus. It was throwing TCM battery disconnect and evap slow leak. So, the headlight blew on the driver's side before my daughter took the car to Long Island, so I decided to take the TCM out completely, add di-electric grease to the connector, clean/grease the restraining bolt, and put it back. Guess what - ALL codes are cleared and have not returned!
Two birds with one stone for sure on this one!

TankII
 

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I'm sorry I haven't given an update, but the G.C. made it to Harrisburg PA and back, only the rough idle to contend with.
How far is that? I hope this was further away then just from Hershey...

I did not read all four pages again. I remember this tale from earlier...

When I first got my 2002 Chrysler mini last year (or more), I went about trying to polish issues including the "other than sewing machine" idle. Compressions were good, consistent. Changed plugs and wires. Cleaned the throttle body. Joined Chryslerminivan.net, read about the injector harness exhaust heat issue, inspected tested and reroute/fashioned a heat shield... What finally made a substantial improvement was that I sent my fuel injectors out to Idaho and had them cleaned and flow tested by Bill.
I experienced smoother idle, quicker starts, and even perhaps better fuel efficiency.

I think I asked earlier if you had green injectors. When I was learning about injectors and the cleaning process, I came across replacement injectors at the chain auto parts shops and online like Amazon and eBay. For my 2002, the factory original injectors were black and manufactured by Deka Siemans.

I believe that those green injectors are clone copies from the far east Asia and I can buy them on Alibaba. I have heard that they run great for a year or so, but then they start to fail, and I have even heard that the plastic they use gets brittle and when removing them to clean them, they fall apart.

I apologize if I am repeating myself, but I am certain that regular, consistent fuel delivery and atomized spray pattern is a key factor in smooth idle.
When I got my injectors back, the pre/post report said that my injectors were not really all that bad. So, I can just imagine a great improvement if someone were to clean up a set that were deemed poor...

Cheers!
 

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Discussion Starter #40
Manchester, GT area to Harrisburgh. Nice six hour drive there and back Day-trip.
We swapped the injectors - the problem didn't follow them. You think I have problems with multiple injectors?
TankII
 
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