Engine stops running after a few minutes

[Everyroadleadshome]

Feel every hose. A split or crack can be invisible. Use a Chiltons and make sure that everyone is in the right place.  I had a Dodge that was a vacuum nightmare. It turned out to have a split on a vacuum connector. I only found it by touching the base of the part and having 

    This triggered a long lost memory.  My very first car was a 1982 Chevy Camaro with Cross fire ignition, what a pos design.  Same problem as the op......car ran great until it got to temp.  Ended up being a vacuum problem.....took forever to find the culprit but once I found the right hose she ran great for a few weeks until the next thing decided to go.....and the next thing....and the next thing.  Learned a lot about cars mechanicals owning her.

[Roadtripp]

Thanks for the ideas. I had driven own very rough roads just prior to the malfunction occurring. And now upon inspection of the computer (ECM/ECU) I notice the blue chip inside was not fully latched down. It might not have full contact inside. I’ll try reinstalling it in a few minutes. 
 I watched one video that claims I can move the chip from my old computer to a new Cordone remanufactured computer. 

The new AC Delco computer on Amazon is $410. A Cordone remanufactured computer is $110 so I may try it. I called Oreillys and they can order Master-craft computer for $100 and $160 that they claim are plug and play, no need to change the chip. 
 Meanwhile, it’s been a unexpectantly pleasant stay in Cashmere.

[Roadtripp]

Disconnecting the battery and reinstalling the computer did not fix it so I’m going to check the vacuum hoses more carefully. I’m spiraling in on the issue. 
  Can order another can of Deoxit as I didn’t bring it with me. 
 But the EGR valve is bugging me. I saw plates are available for $10 to delete the egr. I could try that?

[Gr8ful]

My wife & I were married in 1981. She had a '78 Cordba, I hated that gas guzzler. We were flat broke & the computer went out. $500 from Chrystler, might as well been $50k we didn't have anything close so I was walking/hitchen to work for 3 weeks till I found the new fangled computer had a 5 year warrenty & we were saved. I still hated it, the 8 mpg, I'm 6'4" & couldn't sit up straight. Good luck & hope you hit the right answer soon.

[Blacktank]

when it wont run is there spark at the plugs?

egr-exhaust gas recirculation? recycling?,its a vacuum operated valve that let exhaust gases back into the intake to be reburnt,reducing emissions

issues,
vacuum hose leak
diaphragm broken,depress the diaphragm,put finger over vacuum hole,let go of diaphragm,if the diaphragm inflates its broken,stays put good
the innards can become clogged with carbon preventing the valve from moving,take off and clean

the egr is an emissions devise and you wont pass deq without it

my version of checking for vacuum leaks is to start it up and use a 3-4 section of garden hose,one end to the ear ,other around the vacuum hose,if theres a leak you cant miss it

vacuum leaks will make it not idle,run really bad but should still run unless the vacuum is controlling something vital

is the engine sputtering and trying to run or dead nothing? if dead nothing most likely something electrical/computer

when it wont run you could spray a little carb cleaner or starting fluid in the air intake and see if you get a pop,need to find out if its fuel supply or electronics causing the issue

[Roadtripp]

It runs beautifully then suddenly stops dead. I could not see any spark but then it fired when I poured a little gasoline in the intake!. So I started chasing the fuel supply. Then the next time it didn’t fire when gas was added? I may have flooded it. But I started chasing ignition again. 
 I’m thinking of measuring the resistance of the ignition pickup coil. I read somewhere it should be 800-900 ohms. Maybe I should test the resistance before I run the engine and after it shuts off. 
 And I’ll see if the egr valve leaks. Good idea!
 I want to carry all the small spare parts so just ordered a computer, fuel return regulator, and MAP sensor to add to the box of parts I have already. I already have a spare starter and fuel pump, temp sensor, ignition pickup coil, fuel filter, ignition coil, etc.

[American Nomad Patriot]

Wow...I can relate to your pain. I'm fighting my rig's Second engine and have thrown, chased , cussed , every part of it. A few times through throwing lots of parts at it. And of course you prob know it's still in the shop again. This shit haunts you bad. I feel your pain my friend !! The struggle is real.

[American Nomad Patriot]

My 2 cents on your possible prob. Check every single wire you can get to and make sure every inch is in good order. If one part of any wire is too close to a hot object (like exhuast manifold etc.) it will short out as soon as engine gets to a certain temp. Same shit happened to me on a 1988 Stingray Corvette w/ a hopped up, punched out, 350 v8. It had aftermarket fuel injection system on it. Come to find out some wires were running too close to the headers and soon as it got warm the computer would shut it all down. Doesn't cost anything to check. JMO.

[sternwake]

When the ecm on my Dodge was going out, it first started and ran fine from oernight cold. It was the second start of the day, it would catch, and then relays would click on and off while the engine sputtered caught partially stalled, then recaught, and at some point it would run perfectly.

With more time the sputtering got longer and longer, before it ran fine.

During this time I was throwing parts at it. Coolant temp sensor, throttle body temp sensor. I pulled out nearly the entire wire harness, unwrapped the original electrical tape, ran a wd40 soaked rag over each wire to clean tape reside and inspect for burnt insulation. I rewired the fuel pump with thicker and shorter wire with fewer connections. I found a tremendous amount of carbon build up in the vaccuum passages/ amplifier ports in the throttle body I was sure was it. It wasn't, but it did run better afterwards, when it did run.

The condition persisted and continued to get worse sputtering burping and farting for longer and longer each time. I was convinced it was the engine computer, but was also told it is rare that they fail on their own, there is a cause, like a shorted wire which damages the computer..

I think it was a Cardone PDF that said check the wiring to the transmission solenoids.



this was one section of wiring harness I had not inspected closely. When i did I found one of the wires to the OD solenoid, had chafed on the tx bell housing and the wire insulation was burnt. I replaced that section of wire, and ordered a remanufactured computer from rockAuto. there were 4 different models. I got the federal 4 speed automatic transmission model.

when it arrived engine started and idled perfectly. yeehaw. No overdrive. Boooooo!
I sent it back, got another, same thing. Shitballs!
opened up original computer, saw a part number inside and saw it aligned to the engine computer model listed on rockAuto as for the 3 speed manual transmission. I ordered that one and had overdrive. Yeehaw.

RockAuto did not reimburse me for the multiple return shipping costs. The cardone part numbers were also crossed. They fixed it, but I was out about 40$ in shipping returns. So happy the issue was resolved, I did not pursue reimbursement. I kept the core and ate the substantial core charge. I intend to replace all the capacitors myself and see if it works. I want a fully functional backup ECM.

Fast forward 13 years, was occassionally stalling. Wiggling and holding the one engine computer wire bundle to 14 pin connector would fix it. Zip tie the wire bundle, and all would be well, for a while, then stall click no restart curse fest. wait 30 minutes all would be well again, for a while.

Ordered new engine computer, it would not start, return computer.

Disassemble original remanufactured cardone computer, remove all potting around 14 pins, file soldering tip to shape of base of pins, flux and a new blob of solder, and reflowed the solder on all 14 pins. There was no Obvious broken solder joints, but it was a dual sided circuit board and I could not see the other side. But No more stalling afterwards..

I do have sometimes stall now when low on fuel, and making a left turn. When I replaced the fuel pump in 2006, on the module, I did not put it down low enough, apparently. I just don't let the tank get below 1/8 via the needle, even though there is likely about 7 or 8 gallons left at this point.

Didn't you have some recent transmission issues?

Anyway next time it stalls wiggle those engine computer connectors and try to start it while holding them up down left or right, and order some Caig DeOxit d5 spray, or the one with the applicator brush, and use it on every electrical connection you can find. The amount of crap which came off my TPS and MAP sensor pins was astounding, and it felt like I removed 500lbs from the back of my van afterwards.

[Gr8ful]

Years ago I'd say a coil chorting when it heats up but it doesn't even have a coil. Back to my last of the non comuter diesels. It's a simple thing that drives you nuts. I'd find a forum & ask questions.