2.9 engine miss?

[Spitfire1975]

Bronco Chuck - Think I can back probe somehow the O2 like I would the TPS?

 

[Bronco_Chuck]

yes you will need to back probe. and im sorry about earlyer the voltage schould change from 0 volts to about 1 volt. i would sugest using an ociliscope or a good multi meter that has a high and low memory. because the voltage will be changing to fast for most multi meters to display. the only other thing is make sure your engine is warmed up. and dont be surprised if you come out with readings like .2 volts and .7 volts thats pretty normal. and all tests should be while the engine is running.

 

[StreetRat]

'87 Ranger 2.9L auto 2wd

~I have gots to post this~

In a way, there are two filters. Inside the fuel accumilator is a wix#33268 filter. Clogged to the gills! Previous owner changed it before also. Teeth marks on it.
Blew my mind, I did not know that and never heard of it. As in, any other posts, its not even mentioned, nor in Haynes book. But one of the first filters at Advance On-Line and Napa. Guess more truck owers should be aware of this lil' nugget.
Well, the parts store closed for today.

Check into it... Hopefully this will help others!!!

 

[Spitfire1975]

and where exactly is this?? Excuse the stupidity on my behalf.....but where is the accumulator?

 

[HndMeDnBroncoII]

drivers side frame rail under the doormost guys dont bother with replacing the filter.
also double check all grounds they can wreak havoc in little annoying ways. and the eec relay-double check the plug and wiring. good luck

 

[Spitfire1975]

So I was just reading another post where a guy was saying that spark plug wires can cause a miss issue when they start to break down. Thought I would just throw that out there.

 

[brommel]

Still have issues

I'm Still having issues with my '86- I did the dollar bill test at the tailpipe, and it does get sucked back into the pipe every second or so. I just cant tell if its a misfire or some sort of valve problem. When I alternately disconnect plug wires it starts to spew nasty stuff from the tailpipe, but does not run much worse. One of the cylinders is having trouble - thats a fact - but how to pinpoint the issue?

Bad injector?
valve problem?
plug/wire issue?

Hi Spitfire-

I have the exact same code and issue as you. Heavy load misfire/stutter. I have replaced EGR, DPFE sensor, verified vacuum.. etc. It seems like I may have the same year BII as you as well. Just today I removed the vacuum line from the EGR and blocked it to rule it out as an issue. (No difference.) During engine speeds above 2500RPM the bronco runs well. anything below 2000 and it sounds like a big misfire and the engine feels unbalanced. One thing I know for sure is that my EGR AIR tube from EGR to exhaust manifold has some problems. I thought bypassing the EGR vacuum might makee differnce, but nope.

Let me know what else you have tried.

 

[Bronco_Chuck]

i found the main cause of my problem was one of my plugs were defective. i never would have guessed since i had just replaced them. but i was looking at it after it was dark and sure enugh the spark plug was arcing from about the cerner of the porclin to the hex head. just thought i would throw that out there.

 

[Spitfire1975]

"drivers side frame rail under the door most guys dont bother with replacing the filter."


That is the only filter I have. My truck does not have the metal canister inline type on it at all.

 

[Spitfire1975]

Finally!!! a weekend where I can REALLY work on the truck.
List of things to accomplish:
1. Change fuel filter, plugs, wires, cap & rotor.
2. Change evap. canister & check related egr vacuum lines
3. Check voltage on TPS, O2 and EGR position sensor
4. Clean IAC
5. Time it

Hopefully one of these things will help. Will update each number individually to see if we can narrow down where the issue stems from. Other suggestions??

 

[adsm08]

Start it. Climb up on a ladder or a wooden stool, DON'T TOUCH THE BODY, pull plug wires one at a time until you find one that doesn't make a difference in how it runs. Shut it off, pull the plug, make sure its ok. Also Ohm the plug wire. 5Kohm for every foot of wire. Most should come in under 5K.

Then move on to the rest of the stuff.

 

[Spitfire1975]

Even if plugs and wires are going to be completely replaced?? Guess it doesn't hurt to double check new components....

 

[Spitfire1975]

Ok. Changed the cap, rotor, plugs and wires. Changed the evap canister (used), Timed it to 10* BTDC, Changed the air filter and even changed the valve cover gaskets. Set the TPS to .98 volts. The truck is now idling at 850 rpm's (instead of 900-950) when warm BUT the idle is much worse. Stumbles more and surges once in a while between 800 and 950. Seems smooth at 2000'ish. The "miss", or whatever it is, is much more obvious, but the tailpipe does not suck a dollar bill in at all. The timing light was acting funky as well, almost like the #1 spark plug wire was skipping a pulse (same timing as the "miss").

Could this be more electrical than vacuum or mechanical?? Maybe problems with the distributor? I did not check codes or O2 sensor tonight. Will do that tomorrow.... hopefully.

 

[Spitfire1975]

"and the eec relay-double check the plug and wiring"

Which relay is the eec ??

 

[Spitfire1975]

also, I think this computer more than likely has 300,000 + on it. Could a computer going bad cause this?? I have another.....guess I should put it in and find out....