txnese

Got an '84 with 17K miles that was running perfectly. Went on vacation and got busy with work, so it sat there for about 3 months. When I got back to it, the battery was dead. I replaced it the battery and started it, it was running rough and stalled out a few times. If I slowly give it gas, I can drive it a little, but a lean code does come on. After digging around a little, I found a vacuum line to the cruise control had came off. I put it back on, but that didn't fix it. Any ideas what to check next? Will gas go bad or gum up the injectors after 3 months? Thank you in advance.

s carter

Not horribly but Fuel Contamination is a Consideration, While Busy and on Vacation did it rain a lot or do you live in Humid areas was the car outside.

With the top of the Air cleaner off and Engine running is there a even flow coming out of the injectors onto the Throttle plates

txnese

I live right outside Houston, TX. Don't recall much rain, but we're kinda humid. I'll be getting back under hood after Hurricane Harvey moves out of our area. Thanks.

billschroeder5842

My first thought is that you need to drive it around and put some gas through the injectors. The 84s are a unique bird and (to me anyway) sensitive with the spray cone/pattern susceptible to fuel issues.

If the car runs and idles, drive it around and get the RPMs up. If it still runs lean, we can start to dissect.

s carter

OK this week rain lots of it. If you want to see what your Fuel is like you can take a Clear glass jar (snapple bottle) draw off some gas from tank bottom see if there is water in Fuel or 30+ years of gas Debris that Settled out over the years, Though I Doubt you run the Cheap stuff but Your car Doesn't Exactly Fly thru GAS given it's Miles.

Fuel Filter?

ex-x-fire

Check the fuel pressure, these tbi engines can run on very low fuel pressure. You can Tee in at the fuel filter.

txnese

It's been raining too much to drive it, but I started the engine this morning. Idle started to creep up and stay at 1700. I took of the air cleaner and looked at the fuel spray pattern, looks good to me. I took the battery back off to recheck connections and see if I did something accidently. Nothing obvious. Started the car back up and idle was about 1200. While in Park, I stepped on and off the gas pedal and nothing seemed wrong. I put it in Drive, stepped on and off the gas, RPMs went up and down and it stalled out. Same for reverse. For now, I think it's something electrical, maybe fuel controls. Just don't think it's the actual fuel itself. I'm pretty sure I put 93 octane in it, but would lower octane doing anything like that? The battery I took out before it started acting up, was 100% dead, not even jumper-able. Not sure if that would have reset any learned drivability.

Tom400CFI

Disconnecting the battery would not cause any "learned drivability" issue -not what you're experiencing anyway. Low octane would not cause your issue either. In fact, the CFI engine runs just fine on low octane.



This is STEP #1, with your symptoms. Check the fuel pressure. Spec is 9-13 psi, it should not drop at all, under any condition, and you WANT it to be at the high end of that spec range.




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txnese

Left it running in idle for about 15 more minutes, had a scanner on it. Then it died and wouldn't start unless I gave it a little gas. Wouldn't start or stay running without a little help from the gas pedal. Starting to rain like crazy again, so I'll play with it some more tomorrow.

txnese

Thanks will have to do that on Monday when Harvey gets out of our area. Will keep y'all posted.

txnese

Finally got to test it and fuel pressure never passed 8psi. Got a new pump, strainer and filter ordered. Will update y'all if that's not the problem.

Tom400CFI

8 psi is the problem.

txnese

The assumption I made was that it ran "perfectly" before sitting for 3 months. Probably wasn't running perfectly, but good enough not to bother me. For whatever reason, the 3 months made it worse. Got the new pump and filter in and now it runs "perfectly" : ) Thanks everyone.

65mopar

If it is acting like it is starving for gas then I had the same problem and after many tests I found the coil was bad.
Replaced it and she runs great.