'92 Ranger failed smog test.

[ZMan]

Im gonna do plugs and wires next, i changed them about 40k ago...but the truck sat in the garage for 5 years so who knows whats good or bad on it. Ill put the stock housing back on it too. The only reason i swapped housings is because a friend did it without issues. I didnt change the cat because it was bad, i changed it to change it, if you've seen the rest of the truck you may understand, lol.

 

[--weezl--]

the methyl hydrate didn't bring my readings down quite as much as i was expecting, though it did bring them down... my numbers above are the "in theory" numbers...

but yeah, low octane... not sure how your testing is conducted, but i remember back home they put your vehicle on a dyno looking deal, bring it up to 60km/h, and test it driving, then test it idling... what you can do if it's the idle test that it's failing on, is bring the idle up to like 1500rpm...

thinking about it... oil is a hydro carbon also... i believe... so if you're burning any oil, that could be the cause of your hc reading...

 

[ZMan]

Ya they put it on the rollers, they drove it at 25mph for a while, didnt do an idle test though.

 

[det107]

i would run a bottle of injector cleaner through it... a poor spray pattern could leave you with unburnt fuel... even though you're not technically running rich, there could be unburnt fuel exiting the cylinder, which is exactly what HC is...

I would make a habit of putting that stuff in to reduce injector deposit build-up & remove moisture before any testing-

and then switch to e10 ethanol (10% ethanol)

Just about every gas station around here have 10% ethanol added-

but you can put methyl hydrate in your tank, it is sold at gas stations as a water remover, usually a little 6oz bottle for 7 bucks...

The brand is usually HEET (wood alcohol), which I have been told it is good for carb'ed engines. I would recommend using isopropyl alcohol at every gas tank fill-up. I buy it cheap/or on sale at drugstores. It is a safe fuel additive for injectors. Burns cleaner & keeps engine clean. Again, it reduces injector deposit build-up & removes moisture-

Arco & Chevron gas stations have a 'trade secret' that includes alcohol in gas-

Does anybody recall the "back in the old days" theory that putting in a full tank of high octane/test was a quick tune-up ??

 

[ZMan]

hmm, well I guess it is burning some oil..this is from cyl #3, have yet to pull the rest of them..

edit, sorry its not oil, its gas. All the plugs are coated, including the plug I checked a couple weeks ago, which was dry at that time. Now heres the weird part. I changed the MAF housing back to the stock one saturday, thats all I did, and now it runs like crap, won't stay running, I have to keep it revved up for the first minute or so, then after that it will stay running, but very rough. This is only 2 start ups so far, I haven't taken it for a drive, does it just need time to relearn the housing or what?

 

[ZMan]

well, I changed all my plugs at its still running like crap...I think I might exchange the o2 sensor to eliminate that as a cause...just weird that it started running so bad after putting the stock MAF housing back on..

 

[--weezl--]

I would make a habit of putting that stuff in to reduce injector deposit build-up & remove moisture before any testing-


Just about every gas station around here have 10% ethanol added-


The brand is usually HEET (wood alcohol), which I have been told it is good for carb'ed engines. I would recommend using isopropyl alcohol at every gas tank fill-up. I buy it cheap/or on sale at drugstores. It is a safe fuel additive for injectors. Burns cleaner & keeps engine clean. Again, it reduces injector deposit build-up & removes moisture-

Arco & Chevron gas stations have a 'trade secret' that includes alcohol in gas-

Does anybody recall the "back in the old days" theory that putting in a full tank of high octane/test was a quick tune-up ??

you're right for the most part, just remember that any alcohol based fluid, be it methylhydrate (methyl alcohol...) or anything similar, including ethanol, will deteriorate rubber, specifically o rings on injectors, gaskets, fuel lines... so use it sparingly

hmm, well I guess it is burning some oil..this is from cyl #3, have yet to pull the rest of them..

edit, sorry its not oil, its gas. All the plugs are coated, including the plug I checked a couple weeks ago, which was dry at that time. Now heres the weird part. I changed the MAF housing back to the stock one saturday, thats all I did, and now it runs like crap, won't stay running, I have to keep it revved up for the first minute or so, then after that it will stay running, but very rough. This is only 2 start ups so far, I haven't taken it for a drive, does it just need time to relearn the housing or what?

that's odd... changing the sensor could do that... check to make sure the maf housing is clean, and the sample tube isn't plugged or anything...

just for fun, try unplugging the MAF sensor with the one that makes it not run well... try running it, if it runs better you know you've got a messed up sensor

 

[ZMan]

I didn't change the sensor, just the housing, the housing is clean I made sure of it. just pulled my o2 and its covered in soot, along with the insides of the tailpipes. I'm starting to think its oil on the plugs, i thought they smelled like gas at first but I'm not sure now, a couple hours later they're still wet so thats leading me to believe its oil. I've only driven it 20 miles since the last time I pulled a plug, so something weird happened in that timeframe.

If its oil, do you think the intake gaskets could have failed? the truck has been sitting for the last 5 years, so its possible they could have dried up over that period, I did re-torque them years ago.

 

[ZMan]

I just replaced the o2 sensor, started it up and it immediately died. So the MAF housing definitely did something weird. This is starting to get really frustrating, I've got a house to work on, I can't be screwing around with this thing every day.

 

[ZMan]

I think I pinned down the rough idle, and hopefully the whole issue all together. I unplugged the MAF while it was running rough, and the idle smoothed right out, so I'm just going to replace it, seems I have all the symptons that lead to a bad MAF. Thanks for that suggestion weezl. That still leaves me scratching my head about the oil soaked plugs though..

 

[85_Ranger4x4]

You might unhook the battery and flip the lights on to wipe the memory in the computer so it has to learn how to run again. I had to do that when I modified the intake on my F-150 (it was in the instructions, I didn't try to start it)

 

[scotts90ranger]

yeah, resetting the computer is what I was just going to suggest

 

[OilPatch197]

I would use Techtron fuel cleaner(top recommended add) and/or a regime of Marvel Mystery Oil in the gas. (cheap/works)

 

[ZMan]

Well guys it turns out it was the maf all along. Changed it out after work and the truck runs way better. It's easier to take off from stops, and gear changes are a bit smoother as well, and most importantly, the cel stayed off. I've put about 500 miles on it since getting it drivable and here I was thinking the truck was always that hard to drive lol.

 

[84bluebronco2]

Good news! Get another couple hundred on, and then smog test her!