Quite interesting "No Start" issue

Hi, this one is quite interesting and it keeps me puzzeled:

Car is a N/A 2.5 Lebaron born in 1988

Ok, especially in cold the car started to become very difficult to start. Until it refused service entirely. So one of the many typical No Start issues.

The No Start was: No Sparc, No Fuelpump Engagement. Later I figured that the CE did not come on during cranking!

So I did some testing on the typical, Sparc, ASD, and finally bridged the ASD to see if I could engage.

Now comes the strange part:

The fact that the CE did not come on braught me to beleive that my SMEC must have been gone...

Having had a couple of power boards around I decided to chance my luck to see if with another Powerboard the thing would be sorted.

So, disconnected the battery and swapped Powerboards and voila, - put key in ignition on position, CE comes on, fuel pump engages and first try it fired up. But you may guess it, with this the story isn't over yet....

The moment I stopped the car, It would not start again. No Fuelpump, no Sparc etc.

First thought was, that I had fried my powerboard again. So I left the car like this and returned - let's say an hour later.

For the fun of it I put the key in position and once more, fuel pump came on, CE came on- as if nothing had happened.

This time I didn't start the car but had a closer look at the electronics.
So I left the key in the Start Position without cranking and disconected the HEP. The moment I connected it again, the fuel pump came on immediately.
So I repeated this various times with always the same result.

Now I started the car, and as before it fired up right away. BUT, the moment I stopped it, it would NOT start again with all the No Start Symptoms. So, left the Key in the Start Position and this time even disconecting the HEP did non result in anything.

Now, you can imagine that I kept myself busy checking ton's of things. Finally I ran the battery dry resulting that I had to reload it. Desperate to find out what is going on I used a Start Helper to crank the car. Now, this was not strong enough to crank the car, but it was sufficient to engage the fuel pump.

It was now that I realised that whenever I disconnected the Battery I could start the car without problems. However once I stopped the car I could NOT restart it UNTIL I disconnected the Battery.

Why would that be???????????????????'

I actually now don't blame my SMEC anymore. I feel rather that there is something in the circuit "staying on" after stopping the engine which does not permit that I can restart - and it does go "off" once I disconect the battery. As if it wouldn't give ground to the ASD if it was once started.

Anyone a clue?????

My guess is a bad HEP or connection, ignition switch is bad or the other side of the SMEC is bad.

Hi,

Quick question:

I could try with a Turbo Hep on a N/A car, couldn't I??

I understand the only difference is, that the Turbo HEP would have the SYNC connector in addition. But I'm not sure and only have that HEP.....

Simon mentioned HEP connection, to add to that, I've had the Female ends of the plug connector widen and get loose resulting in poor contact. You can use a small screwdriver or a pick to bend them shut some. See if that helps. It is a strange no start condition:confused2:

Ok, update on this:

The HEP seems to fall out of the potential candidate list. If I disconnect the HEP entirely the problem continues to follow the same pattern:

The example has as a precondition that the Battery was disconnected beforehand:

1. With HEP disconnected:
- Put the Key on Ifnition On Position => The fuel pump engages for its allowable moment
- Put the Key in Off Position
- Put the Key in On Position Again => Nothing happens - no fuelpump, no CheckEngine

The only difference at that point is that obviously the car won't start without the HEP connected.

But this brings down the problem to this:

-> After Battery Disconnect I have exactly ONE try to Start the car with success. Once I have put the Key in the on Position I either have to start the car OR I hace to disconnect the Battery to get a new chance.

This is the weirdest thing I ever had with a Chrysler Car.....

I had something similar happen with 2 different issues...2 different occaasions.

1. Check the HEP wires where they meet the plug...I mean right where the sheath meets the plug plastic. I had one where the sheath had pulled out of the plug becomming uninsulated. The bare wire was exposed allowing them to ground out. Wiggling of the wire would always allow it to start 1 time.

2. The plug at the SMEC needs to have the pins tightened back up. I had the same experiences you describe and couldn't explain it...but that's what it was.

....if that's not it say screw it and go drink beer for awhile:love:

Quote:

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Originally Posted by MopàrBCN

Hi,

Quick question:

I could try with a Turbo Hep on a N/A car, couldn't I??

I understand the only difference is, that the Turbo HEP would have the SYNC connector in addition. But I'm not sure and only have that HEP.....

---

Turbo HEP should work.

Ok,

there is news:

Still I have not found a definete answer. But being in Spain and thus not being able to get my hands on part that easily we did some more investigation.

The fact that I needed to disconnect the battery to be able to restart the car brought us to PIN 41 (J1) at the 60 Way connector. This is the only permanent battery feed. Logic told us that it needs this to keep up error memory and ram memory once shut down.

So we decided to cut it, and reroute it to a switched (ignition switch) circuit. And voila, the car now starts and stops and just runs fine thus eliminating the need of disconnecting the battery. Of cause at a price, now we can't check codes anymore, and idle relearn etc. happens anytime when the car starts. But at least it runs.

We tried as well to disconnect that power feed permanently and as suspected the car would run like this as well but it would idle horrobly and be quite nervous in part throttle.

This was expected because I felt the only function for this feed could be ram memory and if the smec doesn't have it, it can't store any kick cell values etc.

So far the good news.

But obviously this can not be the solution.

On the one hand I do not understand, why the car operates fine once it has the permanent feed connected, BUT then refuses to restart, if you don't disconect it after shut down.

Yes one would suspect "SMEC gone" but it doesn't make sense to me - knowing now this circuit to be the cause of the problem.

I try to understand how energy staying on this circuit, as it has to be, could cause that the smec does not do anything more.

Not only if the car has run, it is sufficient to only put the key into the run position, so that the fuel pump engages for the first time - if at this point I do not start the car I would have to disconect the battery to be able to start the car again.

Anyone??? @Minimopar??? (btw, if you read, watch out for my no start issue 3 years ago - this has been solved finally......I'll post soon...)

Any fusible links in like between the battery and PIN 41 (J1)? Sometimes those can cause crazy issues like this if bad.

Hi,

I finally gave up on this issue with no final conclusion. I just blame the smec.....

The next few days the car will get a 2.2 Turbo 1 Engine transplanted alongside with new electronics, so this Engine and it's electronics are going to retire... One N/A less on global highways.....

Good solution BCN! :clap: