Way off topic 1993 caravan transmission

[Sniper]

24 minutes ago, Los_Control said:

Best I can figure is heat at this time

My thought as well, if you have a heat gun or even a hair dryer you can use it to heat things up in the driveway and see what fails.  I'd start with the coil pack.

 

25 minutes ago, Los_Control said:

If you stick your finger into the plenum it will come out oily and black with soot .... Is that normal?

Maybe, depends on how close the PCV connection is and how oily it gets.  Pull the PCV hose and see how oily it is to get an idea?

[Los_Control]

Hang onto your hat @Sniper wind gust up to 60-65 mph tomorrow.

 

I can try the heat gun and see what happens ... pcv looks normal.

 

Someone is suggesting bad injectors .... I might have to follow that route and see what develops.

I have always carried the original fuel rail over from original engine to the next .... they now have 190K miles on them.

 

I first want to test the two other sets I have before installing ... no problem buying new, but if I could verify first it was the issue ....

 

Either way ... off to cook dinner and wont even poke my head out the door tomorrow ... take care all

[Sniper]

1 hour ago, Los_Control said:

wind gust up to 60-65 mph tomorrow.

 

And I am headed to Sierra Blanca for a job.  Good thing I am not paying for the gasoline

[Ivan_B]

I doubt that the old oil will do much harm. The injectors are also an unlikely culprit. Thinking about temperature, however, do you have an infrared thermometer? Try taking the measurements of various parts/sensors while the engine is fully warmed-up and is still running well. And then compare the same with when it is not running well. Check what things became hotter and go from there.

 

Also, when the car is running poorly, is your battery voltage normal? I was thinking maybe the charging system ain't doing well when warm?

[kencombs]

When it is misbehaving, does spark look the same on all cylinders?  Could be a clue there if only 1/2 of them vs random vs all, etc.   1/2 because of the dual coil setup (internal to the coil) that I think it has where half of it fires half of the cylinders.   Or if it's all then that points to sensor/control circuit. 

 

Crank position sensor came to mind first, but you've replaced that I think. Non-original parts are suspect these days though.    Bad ECM ground?   I'd be tempted to run a separate ground wire, ECM, Chassis, engine just to rule out. 

 

 

[Los_Control]

3 hours ago, kencombs said:

When it is misbehaving, does spark look the same on all cylinders?

I have not checked all cylinders ... I feel swapping coils should mark the coil off the list .... then replacing the electrical wiring to coil also.

 

I have heard many times to always buy sensors from the dealer for oem parts. I have no idea if OEM is still available for a 32 year old vehicle. ... I have no dealer anywhere near me to purchase one.

When I installed the engine I replaced coil, wires, plugs, crank, cam sensors...  Replacing the brand new crank sensor was the first thing I tried .... so I have tried 2 new crank sensors and nothing changed ... while it is still possible, kinda doubtful.

 

I tried a experiment yesterday .... unplug the MAF and then take it for a drive and see if problem disappears.

It idled too fast so I never did drive it ... I let it run and warm up. I believe after it was warm the computer went into closed loop and it ran like total crap. .... I plugged the MAF back in and it ran normal again. Also CEL came on without MAF, went out when plugged back in.

 

So I now think the computer is working properly and is grounded.

 

Over on the Chrysler minivan forum I have been getting some good suggestions, most all of them has been covered from this thread already.

Seems the injectors are color coded for different engines/years.

The current engine came with orange injectors and the engine came from a car.

I installed the black injectors that came with the van ... it was easier.

So next move will be to swap injectors .... I doubt it will help. Seems I tried everything else, may as well swap them also .... they do have less miles on them then the current injectors.

 

I decided to work on the truck over the weekend. Have it back on blocks and ready to paint the last 2 wheels.

The new turn signal switch arrived so I can finish the wiring on it .... install new tires on Monday.

Change injectors on Tuesday.

[Los_Control]

I feel like a dog chasing it's tail. .... All the symptoms and issues point to a bad Crank sensor.

I installed a new sensor when I installed the used engine and have had this problem every since.

 

First thing I suspected was a bad "new" crank sensor .... So I ordered a new one again from rockauto and changed it.

 

I honestly thought I was ordering a different brand and would get a different sensor.

 

 

Real story is, I got exactly what I was replacing ... A NTK made in the USA sensor.

 

So lets say they make 1K of these in a batch, and all I did is buy another out of the same batch?

 

I get it, I'm grasping at straws here .... I'm thinking now that the installed sensor has over 2K miles on it and progressively getting worse ... 

 

The sensor in the photo I was getting 30-40 miles out of it before it acted up.

 

Now with replacement sensor, it started out the same 30-40 miles .... but gradually gotten worse ... I only get about 10 miles now.

 

So I'm going to install this old sensor and see if I can drive further before it acts up again .... Both sensors may be bad ... If I can drive further with this old sensor installed .... it would tell me the aftermarket sensors are junk.

 

I called a dealer yesterday, no chance to get a OEM for a 1993 .... but what brand to buy next?

 

Thinking to just go to NAPA and just see what they offer.

 

 

 

 

[Sniper]

Put the old sensor back in?

[Los_Control]

12 minutes ago, Sniper said:

Put the old sensor back in?

I'm thinking it is possible a bad batch of sensors were made ... they all are defective the same way.

When new they run about 30-40 miles then get hot or act up .... thats what the sensor in above photo did when I pulled it out and replaced it. .... It had about 200-300 miles on it. And the car drove 30 miles before acting up.

 

Now the exact same new NTK sensor installed, has about 2500 miles on it, can only drive 10 miles on the highway before it acts up ... when first installed it would go 30 miles, just gradually getting worse.

 

I hope the sensor is bad ... all the symptoms points to a crank sensor ... just confusing because already tried 2 new crank sensors ... of the same brand and likely from the same batch.

 

I'm thinking, if I install the 1rst used sensor again ... if I can now drive 20-30 miles instead of only 10 miles.

Would mean the sensor directly affects the problem. ... I need to buy a different brand of sensor.

If I can still only drive 10 miles and it acts up ... I know it is not the sensor and this one is new also ... just leave it.

 

Is a really easy job on this van, 1 bolt and plug, can lean over the fender and easily reach it .... worth a shot.

Wife is out driving the neighbor to town grocery shopping ... will change it when she gets home and see if there is a change.

 

I'm really going nuts on this thing. .... wife is home, I'm going to go change it and try it.

[Los_Control]

OK another swing and a miss ... not surprised though.

 

While I was hoping to get 30 miles before it acted up, I only made it the typical 10 miles on the Highway .... But the car was fully warmed up from the wife driving it before I worked on it.

 

I need to wait until the morning then start and go and see what happens. ... Just not a equal test starting with a warm engine   😕 

[Sniper]

I  meant the original, factory one you replaced when doing the swap.

[Los_Control]

4 minutes ago, Sniper said:

I  meant the original, factory one you replaced when doing the swap.

That one actually started this whole process ...

It failed and needed replaced .... I installed it wrong and that caused the original engine to blow up.

Then the new/used engine failed at 50 miles ... 3 engines later and a few new crank sensors   🙄

 

Original factory sensor is long gone and talking to the dealer, they can not get a 1993 sensor.

The sensor is bolted to the bell housing of transmission ... you do not get a OEM sensor with a used engine.

 

To give it a fair test, I feel like I need to let it sit over night and then take it for a drive .... same time the sensor I installed was room temp when installed. ... So my theory is BS.

 

At this point, my only thought is to just keep driving it and it just keeps getting worse.

Eventually it simply will not start and run, and maybe then I can chase down the issue and find where it fails.

 

I'm moving forward with the 49 and it may soon be my only driver   

Wiring is kinda finished, I'm going down on May 1rst to license it. Thats 5 days from now and I need to put the seats and interior back together and bleed the brakes ... Maybe next week it will be a driver.

 

My daily driver chebby I think it has a bad ball joint and suddenly want to eat the driver front tire.

I'm going to tear the front end apart and replace all worn parts ... then tires ... it will be down a few days ... I'm going to have to rely on the Dodge .... sure would be nice to have the caravan repaired ... just not in the cards.

[Sniper]

Well, if you really want an OEM one

 

https://www.ebay.com/itm/395160718796

[Los_Control]

Thanks @sniper .... I'm kinda giving up on crank sensor issues ... I had to try though.

 

You also pointed me to a coolant sensor I was unaware of. ... seems this engine has 2, one for the gauge and one for the pcm.

I changed the coolant sensors with no change.

 

Now someone is suggesting a possible oil pressure switch going out and cutting the engine off???

Is that even possible on a 1993? ... I Dunno

 

I think this will be the next item I try

 

[Los_Control]

Well life goes on .... I was so pissed at the car I did not drive it .... until yesterday.

Fact is, with the different sensor installed .... really was not driveable.

 

So I put the old crank sensor back in today. .... kinda sorta better but in the end I do not want to drive it.

 

My experiment really did not go the way I expected it too .....

I do not think the different crank sensors were the issue .... tugging and moving the wires to the crank sensor made the difference.I now have 3 different codes that I did not have before

 

14 ... MAP voltage too high or too low
24 ... TPS voltage too high or too low
43 ... Ignition control circuit not responding

 

So I'm now going to go after this wire harness .... I think moving the wires may have told me what I need to know.

 

I did go after the harness on the top end of the motor that  controls the PCM and all the main parts.

The wire harness for crank sensor comes from underneath and with the transmission harness .... I never searched there before for this issue.

 

I just feel like I may have a clue where the problem is ..... 😕 

 

 

[Sniper]

Endeavor to persevere

[Veemoney]

1 hour ago, Sniper said:

Endeavor to persevere

🤣😁

[Los_Control]

Just sayin .....

There is a 90 degree bend in the harness in the photo.  .... At this point, someone had wrapped it tight with electrical tape and then put a zip tie on it to keep it tight. ..... I had already stretched it out, but the bend just comes natural now.

 

So I really suspect I have broken wires here in this harness at the bend.

Messing around with the harness created different issues including a CEL and shifting issues .... is also transmission sensors in this harness.

 

So I'm really excited and think I found the whole issue .... I repaired the harness.

Now all CEL codes went away, it runs great .... I can now drive 35 miles before it acts up again .... right back where I started from   

 

Seems it was gradually getting worse and causing issues sooner .... I repaired the harness and now I know .... been fighting two different issues.

Repairing the harness fixed one issue .... now am back to drive 35 miles and it starts to act up .... slow down and can drive further.

 

I ordered a different brand crank sensor today. The transmission bellhousing gets warm to the touch when driving it.

I can only assume the crank sensor is getting warmed up and failing .... works fine when cool.

I have tried 2 crank sensors already with same results .... this time I ordered a cheaper Walker electronics product.

Feels like I'm going in circles.

[Eneto-55]

The "starts and runs great for awhile then it don't" situation reminds me of a VW we had in Brazil. It was an "alcoholic" (burned straight alcohol), and had to replace the carb right away when we got it.  But it would start & run fine until I got into town and stopped at a light. Then it would die, and when you started it again it would sounded like it was running backwards.  So we quit using it to go to town, and just used it on the mission center (almost 1 mile around, and it's nice to have your own car during rainy season in the Amazon). Then when we moved back to the States we gave it to another missionary couple, who discovered that it was the 'Hall-Effect' (I think that's the right term) in the distributor.  I have hesitated to mention this here, because I assume there is no such animal in these later model engines. (It was an 84 model.)

[Los_Control]

1 hour ago, Eneto-55 said:

The "starts and runs great for awhile then it don't"

Yes, there is no distributor on this engine ... crank and cam sensors controlled by computer.

 

I think I have exhausted all known possibilities ... It acts like a bad crank sensor, spark getting erratic after it runs awhile.

When I messed with the harness and found that moving it around would change how it ran and throw codes.

When it was running bad and not driveable, I made a splint with a Popsicle stick and taped the wires to the stick.

Then it ran fine again and the computer cleared the codes and CEL went off .... So I know there were breaks in that wire harness and corrected them.

 

The crank sensor wires are in this harness, confirms my suspicion it is a crank sensor related issue.

While it acts up less frequently with the wires fixed, it still acts the same way when warmed up and then comes and goes.

 

There is a lot of heat in this area with the exhaust cross over pipe and the transmission housing gets warm ... just guessing it is heat related and the new sensor breaks down under heat ... new sensor is $18 and in the mail ... I will try it.

[Sniper]

You know a good OBD2 scanner would show you the crank sensor signals. And then you would know if that's what was acting up. But $18 is a heck of a lot cheaper than a good OBD2 scanner

[Eneto-55]

3 hours ago, Los_Control said:

Yes, there is no distributor on this engine ... crank and cam sensors controlled by computer.

 

I think I have exhausted all known possibilities ... It acts like a bad crank sensor, spark getting erratic after it runs awhile.

When I messed with the harness and found that moving it around would change how it ran and throw codes.

When it was running bad and not driveable, I made a splint with a Popsicle stick and taped the wires to the stick.

Then it ran fine again and the computer cleared the codes and CEL went off .... So I know there were breaks in that wire harness and corrected them.

 

The crank sensor wires are in this harness, confirms my suspicion it is a crank sensor related issue.

While it acts up less frequently with the wires fixed, it still acts the same way when warmed up and then comes and goes.

 

There is a lot of heat in this area with the exhaust cross over pipe and the transmission housing gets warm ... just guessing it is heat related and the new sensor breaks down under heat ... new sensor is $18 and in the mail ... I will try it.

Speaking of heat, if the wires are nearly broken in two, or even completely broken, but just making contact at the ends of the break, then that will produce heat as well as the heat from the engine, and may cause the connection to start to fail.  I cannot remember where I saw something like this, but I have a vague memory of finding that as a cause.

[JBNeal]

Have ya looked at the connector between the sensor and the wiring harness?  Sometimes them pins rattle around in the mating sockets, creating intermittent contact.  I have remedied this by ever so slightly bending the pins to force contact with the sockets...alternating directions of adjacent pins helps; limit bend to width of pin.

[Dave72dt]

It's a '93.  That should be OBD 1 unless you have an OBD 2 with adapters and capable of reading OBD 1   I believe the crank and cam sensors are both hall effect.  Still sounds like a ground issue to me.

[Los_Control]

2 hours ago, JBNeal said:

Have ya looked at the connector between the sensor and the wiring harness? 

Possibly I may have to cut that connector out and replace it ... Wait and see, but something to think about.

 

Way back in 2021 I started this thread because I had a transmission problem ... was stuck in limp mode.

Took me awhile to figure it out .... it was this very same plug that was the problem.

The connections were corroded and besides the crank sensor, it also has the main power wire to the Transmission computer.

Once I cleaned this plug, all my transmission issues disappeared.

 

4 years later, I'm having a crank sensor issue "I think" and here is the same plug a month ago.

Not disgusting, but a small amount of crud did come back on the tips ... I have cleaned them again.

This is also the same plug that I just shortened the wires on yesterday. ..... I have had issues with this plug in the past.

I may end up cutting the plug out and replacing it with something different .... Not ruling it out anyways.