Ranger is running very rough all the sudden! Whyy???

[rangerI983v62.8L]

Its a 1983 ford ranger v6 2.8L v6, bought it running (rough), I installed New: wires/rotor/cap/plugs/fuel pump/oil sensor/ignition switch/ new oil and filter/and a few bulbs and head lamp(1). I also did: seafoam in the gas tank/vacuum line/and original oil when i bought it. After math: IT WAS RUNNING GREAT! However. The other guy that owned it removed the condenser and the heater has a hole on the the coil cover on the dash. My lovely girlfriend Natalie decided to turn it on. Then all the sudden it got a little hot. I burped the radiator today, all temps. are back to normal. While i was checking the temps, I left it idling for a few minutes and it died on me. I turned it on after a few cranks and its running rough!, really rough! Its lost all that beautiful horsepower. I dont know what could be happening here. It went from great to ROUGH!. ANY IDEAS?...anyone please?

 

[ab_slack]

I don't know if the 2.8L has the same head cracking issue as the 2.9L. The 2.9L (which I live) had a problem where in a overheat condition they head was likely to crack. Given what you said this is the only thing that comes to mind as direct connection. But a little hot isn't necessarily overheat. And I think a cracked head might show some white smoke. I really don't know how to diagnose such other than looking at plugs and see if one looks different, but that may take awhile to show up

There are so many things that can happen that may have been coincidental. It is possible that there is something intermittent and all the work you did hadn't solved it and it was just running nice to make you think you had. I don't really know the 2.8L. I would check general stuff such as making sure no issues with plug wires or any vacuum lines. Those sorts of things can get better or worse just be some movement. With newer wire sets I have had recently, I have problems getting a good affirmative connection at plugs. The boots were too tight and the contact was too lose. I ended up compressing the contact a little and using long nose pliers to spread the boot till I was able to get an affirmative "click" that I could hear and feel at each plug.

As far as vacuum lines feel around, see if anything makes a big difference. Any cracks or ones not sitting on tight could be a problem. Sometimes spraying on some carb cleaner can temporary seal and improve operation.

I am a hack at this, hopefully someone with experience with the 2.8L will chime in.

 

[drsvox]

It shouldn't take you long to trace and check the vacuum lines, but isolating a vacuum leak can be somewhat of a pain. Also, vacuum leaks can be due to the lines or improperly torqued carb/carb mount/intake manifold/etc.

If the emissions sticker is missing from your 2.8 (under hood, top-radiator support), use the one from the tech library: http://www.therangerstation.com/tech_library/diagrams/1983vacuumhoseguide.jpg

You did a lot of work to the ignition system, but how about replacing the ICM (back of the distributor)? If the ICM on your 2.8 is old (and I'm assuming it is), it's possible the overheating affected it. Replacement modules range from around $45 to $100+

If you do replace the ICM, this would be a good time to inspect the six wire connector to it...

Also check out and search the 2.8 forum on this site. You may find someone had a similar problem.

 

[kimcrwbr1]

If it is still running on the computer it could be any number of things. Disconnect the battery and go through and clean and check all the connectors are clean no wires are shorted and that everything is plugged in. check all the vacuum lines are connected in their proper places. then start it and see if it runs any better. If you continue to have issues do you need to pass smog tests. If not do the duraspark conversion you may never get it running good with the computer. You can pull the codes with a analog volt meter or a test light how much time and money do you have?

 

[kimcrwbr1]

All the sensors must be connected and working before you reset the computer by disconnecting the battery if not it will go into limp mode and just run on base timing and run like ass.

 

[drsvox]

Get a manual too, from AutoZone or AAP. I have a Haynes, and while not entirely the best resource in the world, it has and does come in handy.

If I'm not entirely sure what the problem is, here's how I troubleshoot using the manual:

- note everything applicable to the problem, for example:
-- hard to start when hot
-- erratic or misses at idle
-- lacks power
- then list out what the manual "thinks" may be the cause to each of the noted problem areas; the manual should list in order, most common cause to least common cause
- match up consistencies in each area and start with them first; process of elimination

It can be a long process, and like kim asked: how much time and money do you have...?

 

[Canndspam]

I also don't know the 2.8 well but could it be your O2 sensor? Theres ways to test 02 function with a multimeter but you can also just unplug it and see if that changes how your engine runs and ulitmately a new one is something like 10 bux at rock auto. I had weird running issues for a while where I replaced a lot of ignition and fuel components that turned out to be an O2 problem. Maybe a better question is does your year even have an O2?

 

[SRich]

What plugs did you use?

 

[drsvox]

Maybe a better question is does your year even have an O2?

yes. driver's manifold and very easy to get at.