3.0 Caravan won't idle

[mulman]

Hi,
I am hoping someone here can offer some helpful diagnosis.

I have a '95 Caravan 3.0L A670 93K miles. The valve lash adjusters were making a terrible ticking racket so I decided to replace them all. While at it, I replaced the (original?) Champion plugs with Autolite 64 plugs (corresponding part number). In the process of pulling the rear cam cover I had to disconnect the wires from the alternator and unplug the injectors (single plug connector), MAP sensor, coil, and water temp guage, all after disconnecting thr battery.

Upon reassembly, the van won't start unless I push the gas while starting it. It will idle low (800 rpm or so) and very lumpy. If I put it into gear, it will die on me. I did use moly gear lube to temporarily hold the adjusters in the rockers. Maybe I contaminated the oil hole and the adjusters won't fill with out therefore not allowing for enough valve lift? I did run the engine with my foot on the gas for a bit to get enough oil pressure to clean out the holes and fill the lifters.

I swapped back to the original plugs. Idle maybe a little better but otherwise same low lumpy idle and stalling when put into gear. I checked all the ignition wires and they are correct. I put a timing light trugger on each of the wires and they all activate the light, so they are all firing.

I tried the key dance and it spit back 12, 14, 55. 12 means the battery was disconnected. 14 means low or high MAP sensor voltage. 55 means end of codes. I figured I'd replace the MAP sensor (why it would go I have no idea). New sendor from Autozone (Wells SU339), same problem. I thought the wiring might have been caught on something but the three MAP sensor wires each have continuity to the plug under the master cylinder.

I'm stumped! Why the MAP error code? What did I do wrong? I miss carbed cars!

Any thought and/or suggestions welcome. Thank you in advance.

Mike
Reading, PA

[mulman]

OK, here's an update...

I unplugged the negative battery terminal when I came home from work to clear the error codes. Reconnected after the kids were in bed and while the engine didn't run right, the only codes I got were 12 and 55, so no error codes were registering.

I started to think about how I was pulling the multipin connector for the injectors to get it out of the way of the rear cam cover while pulling the cover. What if I have a bad connection to one of the injectors. Well, the only one I can reach without taking off the air plenum is #6. I unplugged it and started the engine with it disconnected. Oddly, the engine seemed to run kinda okay! I turned it off and checked codes: 12, 27, 55. So, it detected there was an injector issue. I reconnected the injector and restarted the engine. It didn't wanna start right off but seemed to run fine. Very odd. I disconnected the battery to clear the codes and rechecked the error codes: 12, 55.

I reassembled the airbox and took it for a test drive. Initially it stalled on an uphill. Then I had no issues going up the same hill. I even went down and up my 600 foot long and very steep driveway and no problems. I stopped at the steepest part, and then continued up the hill, no stalls or issues.

So, was there a bad connection to injector #6? Not enough to trigger an error but enough to keep it from running right? It ran better with #6 injector disconnected than #6 injector poorly connected!

When you have a problem that you diagnose and fix, you have some level of confidence that the problem is fixed. Here, I am real uneasy about the reliability since I don't understand what went wrong in the first place!

Thanks for your help. Any thoughts on my rantings above would be appreciated.

Mike

PS
The thing that prompted this exercise was changing the lash adjusters to get rif of the ticking. Now, it ticks when you start it, but after revving a bit its quiet. Not what I was hoping for, but better!

[peter_x]

I also just replaced my adjusters:

http://www.dodgetalk.com/forums/showthread.php?t=219639

When you removed/reconnected the #6 injector, did you do the same to the main injector harness? If not, it seems odd that the van became smoother because you hadn't touched the #6 injector before (It seems you are saying you didn't need to remove the intake like I did, so you wouldn't have removed the injector plugs). Although if you did remove/reconnect the main harness, I bet that is what fixed it right there.

[mulman]

I did not take the air plenum off. I managed to get the valve covers off without doing that. Actually, the intake rocker for the #1 cylinder was in the way so I had to rotate the engine to close that valve before the valve cover would fit the rear bank. I somehow managed to remove it without doing so, though I did bend the inner sheetmetal of the cam cover where it hit the rocker, but I think I straightened it out and hopefully there is no oil leak.

I disconnected the multipin plug that powers the six injectors and I did sorta move the connector out of the way. It is feasable that I pulled on the multipin connector and loosed the individual injector connector(s). But why did it not register as an error code if it was a bad connector to injector #6? And why did it run fine on 5 cylinders? I'm confused! It ran last night. It ran this morning. It ran at lunch. Will it run after work???

Thanks.

Mike

[StandOnCliff]

Sounds to me like the lifters just needed to fill up with oil. Did you put them in fresh oil and let them soak oil into them before installing them? If you didn't prefill them they would not have had oil in them basically until the oil was close to operating temperature. This would of been known by the loud valve chatter. Using pre-lube is recommended. Grease takes longer to break down. Being all your valves were opening only half way it would of been running like crap.

[scotto]

I would like to add one suggestion, I see on those engines that many remove the plug wires then reinstall them thinking in the same way you would change them on a old Charger for example. On a 3L dodge the female plug in on the cap does not end directly below the plug in. They jog over in different directions. I know I'm grasping here, but I have seen it happen too many times not to ask.
Please recheck the firing order.