Way off topic 1993 caravan transmission

[Los_Control]

Thanks @JBNeal I agree .... just a weird issue and been chasing it.

From google ....

 

Engine stalling The vehicle stalls after starting, The engine loses power at higher speeds, and The engine hesitates when accelerating

 

This is exactly what I see at this time .... from google for examples of a bad fuel pump relay.

I have to try swapping it out, just not sure exactly which relay it is .... I will figure it out tomorrow and swap them around.

[Los_Control]

Yeah I just do not know of a way to test relays  .... I'm aware I can swap one relay for another to test it that way ...

 

I paid $28 for a horn relay from NAPA last week to connect the horn on my 49 Dodge ... I might use it.

 

Just too late in the day to pinpoint the exact relay to replace .... tomorrow I will figure it out.

 

I told my wife I think I finally figured it out after cleaning the connections  .... she laughed and said come back with no story telling   😕  

 

Maybe tomorrow

[Sniper]

That's the thing about fuel injected cars if the fuel pump stops working you instantly lose fuel pressure and the engine shuts down there's no Reserve in a bowl like a carburetor has. I've known guys that wired in a test light at the fuel pump connections and ran it to the dash to see if that light stayed on while they were driving and if it's shut off when they had problems that would tell you whether or not electricity was getting to the pump connection. I don't know how feasible that is on your mini band it's been a long time since I fooled around with a minivan

[Sniper]

I have a pressure gauge hook to a hose that screws onto the Schrader valve on a fuel injection fuel rail. It's only about a foot long so I just use it under the hood to test pressure but if you can simulate the stalling in your driveway you could probably do something similar and watch the pressure gauge to see if your fuel pressure drops off when it stalls. It should not since the pump is electrically driven and not driven by the engine

[Los_Control]

Great ideas @Sniper My fuel pressure gauge is same with a 10" hose.

Pretty obvious I know nothing about relays    ... I did not figure they could fail in this way.

I assumed they either work or they do not.

 

The car has 5 relays on the drivers fender .... I assume it is the ASD relay ... what they call it ... I call it fuel pump relay.

Auto shut down turns off the fuel pump iirc.

 

They are all typical 4 or 5 pin relays, like I just installed on the truck for the horn ... I might be able to swap out the AC or radiator fan relay just to test with.

I will head outside pretty soon and check it out ... probably end up driving it to the parts store and just replace it.

 

On the other hand, I have not pulled any of the relays to clean the connections ... might have to investigate if they are dirty.

 

[Los_Control]

I almost want to say .... Thankfully it is getting worse   🤣

Today I was able to reproduce it in the driveway for the first time ....

I was able to put on the fuel pressure gauge and my spark plug tester and monitor it while it acted up. Fuel pressure is fine, 45 psi exactly what it should be, then actually raises when the engine cuts out.

 

Spark going to the plugs is erratic ... spark looks normal on one cylinder while the engine cuts out.

Then the engine runs normal and then the single cylinder I'm checking, starts to fade out ....

What I think is happening is the cylinders are randomly losing spark .... the cylinder I'm watching is good while the engine cuts out .... then a few seconds later same cylinder is bad when it cuts out .... so different cylinders are randomly cutting out.

 

I'm going to have to think on this a few days and am open to suggestions.

This engine has a single coil pack with 6 plug wires coming off of it. .... I already double checked that. The original coil gave no issues ... I replaced it when I replaced the engine and then tried the original agan and put the new back on .... is not the coil.

 

My first choice was replacing the crank shaft sensor ... I installed the engine with a new sensor, the first item I replaced was the new crank shaft sensor when the problem came up ... makes zero difference changing sensors.

 

I have swapped the main computer ... no change.

 

I have been told that a cam sensor only helps start the engine and could not cause this issue .... it is new.

 

I'm starting to wonder if the ignition switch is going bad? I'm looking for ideas on this one.

 

 

[Dave72dt]

It still sounds like a corrosion issue especially with it becoming more prevalent.  What does the ground end of those sensors look like.  Chrysler grounded O2 and  EGR sensors to a common ground wire eyelet in later years, separate from the main battery to engine ground.  I'd suggest visiting a dealership, buying a ground wire distribution schematic and hunt their grounds down as well as an ignition schematic.  Schematics are available online as well.  Are you still getting the same codes?  The computers probably have default settings that may allow it to run, albeit poorly when receiving erratic signals.  

[JBNeal]

I wasted a ton of time working on a friend's 03 CTS...durn thing would randomly brick.  Long story short, GM ran a ECM ground wire so short that the conductor strands pulled apart inside the insulator at a 90° turn around one of the heads without tearing the insulator...so intermittent ground path would lead to ECM shutdown.  Ya might want to run some temporary grounds parallel to see if that might help.

[Eneto-55]

6 hours ago, JBNeal said:

I wasted a ton of time working on a friend's 03 CTS...durn thing would randomly brick.  Long story short, GM ran a ECM ground wire so short that the conductor strands pulled apart inside the insulator at a 90° turn around one of the heads without tearing the insulator...so intermittent ground path would lead to ECM shutdown.  Ya might want to run some temporary grounds parallel to see if that might help.

That coincides with what I found when I unwrapped the engine wire harness from the 93 T&C I scrapped out - various wires were broken, or so nearly severed that contact might have been intermittent at best.  (In comparison to the wire on my P15, the strand count for a similar gauge wire is much higher on the old vehicle.  I wonder when vehicle manufacturers started using lower strand-count wire, and if it was a slow transition.)

[JerseyHarold]

Try wiggling all the wires connected to the engine while it's idling (be careful!) and see if doing that makes a difference in the way it runs.

[Los_Control]

Lots of good ideas here .... check the wiring is the common subject we all agree on.

And I agree also because I have already changed everything else.

I have another engine harness that looks like it is ok ... this harness came off of the engine. I installed my original harness that came with the car.

 

I see there is a difference on the charging system connection, but I can separate the sensors and coil wiring from it.

I suspect that if there was a internally damaged wire, it would be in this harness that controls the coil and probably ASD also.

 

I do not like this area here, the harness runs right over the top of the exhaust and would get pretty warm.

Because the engine runs fine when cool, possibly when the exhaust gets really warm the heat affects the bad wires?

While this is how it was done from the factory, maybe change the harness and fabricate some sort of heat shield to help protect the harness. .... I also have a extra fuel injector harness I can swap if needed ... not having issues with injectors though.

 

That will only cover the engine ... I will have to inspect the body harness also that controls all the relays and the ECM.

There is a ground wire that I think is too short or should have been longer .... it is coming from the body harness and possible it is for the ECM ... I dunno but I will fix that and look for other questionable items.

 

Will take a day to remove some of the front dress and the plenum, battery/tray to get to everything.

Then spend a couple days going over the wiring ... will start on it Monday, weather will be good again.

 

This car has sure been a challenge for such a normally dependable daily driver  🙄

[Eneto-55]

I should have told in what area of the engine harness I found broken wires - the reason I mentioned strand count is that the broken wires were in the areas between the engine and the firewall, or other places where they crossed from the engine to the body. That is why I did the strand count, because I was assuming that the damage was due to flexing.  But the harness wrapping in those areas, and also the wire insulation itself, that was all very stiff, from the heat, I would suppose. So any shields you can fabricate would probably be a good idea.

[Los_Control]

1 hour ago, Eneto-55 said:

I should have told in what area of the engine harness I found broken wires

 

 

That particular area I always had a bad feeling in my gut about it .... I really would not be surprised if that is where the problem is.

 

Because I plan to change those wires and fix other possible issues at the same time .... I will never know if it were those wires, or possible grounds or other things I fix.

[Ivan_B]

Non-applicable things were here; I'll come back with something else later 🙂

Edited yesterday at 07:50 PM by Ivan_B

[Los_Control]

 

@Ivan_B There is no CEL on, last time I checked there is a stored code for running rich ... that does not trigger the cel though.

It is randomly losing spark to the plugs ... so when a cylinder cuts out and still getting fuel ... makes sense it is rich.

Currently what I'm looking at  .... still getting the body harness opened up.

 

Because the way the spark acted ... I think it has to be the wires that power the coil, or possibly in the wiring for the ASD relay. .... A bad ground could also be at fault.

 

I have what is needed to replace the coil wires from the coil end and will have to splice and solder into the main plugs in the photo.

I'm still concerned about other wires in the harness ... they are hard and no longer flexible because of heat from the exhaust .... while they still function and do what they should ... I will feel better to cut out the damaged and solder in new.

 

Another example of what I'm finding .... The factory clips that hold this harness up, broke long ago.

the harness runs the full length over the header and is melting the plastic covering protecting the wires.

So I'm just going to spend a couple days going through replacing wires and making things better then before.

 

Good chance I might not fix it this way, a chance I may fix it .... at least I will know the basic harness is in good shape, while now it is questionable, and a future problem.

 

As a side note, the 2 extra harness I have, already have previous repairs in the same area ... the one installed is a virgin and never repaired ... I may as well keep and repair it.

[JerseyHarold]

I once had a Buick with a misfire no-one could pin down.  One night, I opened the hood and started the engine, then misted the engine with a light water spray.  There was a very visible arc from a coil pack, which was the source of my problem.  Doing something like this may work for you.

[Ivan_B]

Okay, I've read the entire engine saga... I would probably do some more troubleshooting before cutting into the harness, etc. Can't imagine faulty wires doing fine at 50mph and then somehow loosing it at 74.

 

Let's re-evaluate the situation. The engine starts to work poorly, intermittently, at (mostly) high speeds and after driving for a while, correct? What's different at those times, in comparison to your normal driving? How do you know that the spark is bad? What kind of tester do you use and what is it showing? What kind of distribution does this engine uses, all electronic, mechanical, or a combination of the two? What's your battery voltage like, during these poor running times?

 

[Los_Control]

14 hours ago, Ivan_B said:

Okay, I've read the entire engine saga...

I feel sorry for you ... it has been a ongoing saga.

 

I took a break from working on it recently and took time to think about it ... we just continued to drive the car around town.

It has progressively gotten worse and for the first time I was able to create the situation in the driveway.

Just using a in line spark plug tester I was able to monitor the spark going to one cylinder.

When the engine ran smooth the spark was fine and steady .... at times the engine would act up and the spark turned very erratic or sparse ... sometimes there was no spark at all and engine died at a idle.

I now know without a doubt, it is a spark issue and not a fuel issue.

 

The engine has a cam/crank sensors and 1 coil with 6 plug wires coming from it.

I replaced the crank sensor twice and no change, same with coil, it has a new ASD relay.

I feel more then I know, it is losing power to the coil ... I should have done more testing on it to prove it.

 

I still do not trust the wiring harness where it cross over the exhaust ... at one time the loom came loose and got hot.

With the extra wire harness I have around, they all have repairs in that area.

On this harness you can see 3 wires have some black shrink tubing with a yellow stripe on it. A previous repair where the harness crosses over the exhaust .... other people have had wiring issues in this area ... I have another harness and it also has repairs ....

 

My original harness so far has no previous repairs done to it.

Everything works with no issues, except erratic spark going to the coil.

In the photo is a plug and 4 wires for the coil, I will cut my coil wires out and replace with a different one all the way from plug to plug.

 

I spent the day inspecting and looking at all the wiring and since everything but the coil is working right ... I'm just going to wrap it back up and put everything back together ... with new coil wires.

I'm hoping that will fix it, but prepared to accept it wont .... I will not have to wonder about condition of harness because it is inspected.

 

 

 

[Ivan_B]

Well, okay. If you are confident that the problem is the intermittent lack of spark, troubleshoot the power coming to the coil and its respective output. However, depending upon how that EFI is made, I suspect that the ECM could be cutting the spark, as well, under certain conditions. So don't be surprised if the lack of spark turns-out to be the effect but not the cause.

 

Also, have you already posted on a car-specific forum, such as this one? https://www.chryslerminivan.net It sounds like there is some pretty tricky troubleshooting bits about these older vans.

Edited 2 hours ago by Ivan_B

[Los_Control]

17 minutes ago, Ivan_B said:

I suspect that the ECM could be cutting the spark, as well, under certain conditions. So don't be surprised if the lack of spark turns-out to be the effect but not the cause.

I fully understand that. Possible the ASD is cutting spark also ... even then, every physical part has been replaced or tested. Including the ECM ... the only thing left because of my shotgun approach is the wiring.

So at least the coil wires will be eliminated and everything else will be out in the body harness to check.

 

Thanks for the tip on the forum link, I will take a look at them .... I belong to a few forums, Dodge forum is one.

They are kinda lost when it is not a Dodge truck with OBD2 and live data to read ... but a good bunch of guys to chat with.

 

I also have my daily driver chebby truck and hang out on the Silverado forums ... good bunch of guys and some good mechanics .... OBD1 ... forget it ... not many out there that care enough to drive these old rigs, and familiar with them.

And I'm taking a crash course on learning my way around them