BroncoII4x4.com

I failed by one thing :(

The NO ppm results at 15mph were within spec (by 1 point)

The NO ppm results at 25mph were outta spec (by 110 points)

What can I do to lower the NO (nitrous oxide) reading? I drove about 25 miles, stop and go traffic, before I got to the Exxon gas station near my job to do the test. The truck sat for about 15-20 minutes in about 40 degree weather before being tested.

Prior to the test, the vehicle was inspected for exhaust leak(s) and 0 were found.

Test Results

15mph HC ppm limit 164 - reading 32
25mph HC ppm limit 159 - reading 18
PASS

15mph CO% limit 1.38 - reading .26
25mph CO% limit 1.78 - reading .16
PASS

15mph NO ppm limit 1110 - reading 1109
PASS
25mph NO ppm limit 1015 - reading 1125
FAIL

DAMNIT!!!!!! I did some reading and it seems the EGR valve can be stuck open or I have a bad O2 sensor - but I'm not getting any "check engine" codes. Some say the cat may be bad or clogged - but my cat passed - as you can see.

Positive crankcase venitlation system - PASS
Catalytic Converter - PASS
Fuel Evaporative System - PASS
Thermostatic Air Cleaner System - PASS
Gas Cap Pressure Test - PASS
Visibile Smoke Inspection - PASS

where is the EGR valve on the '90 BII?

oneway wrote:where is the EGR valve on the '90 BII?

there isnt one

so places sell the EGR valve gaskets for a part that's not on the truck?

http://www.jcwhitney.com/jcwhitney/cate ... muniversal

86/87 had um

oh ok thanks. That Jc Whitney link above is for the EGR valve gasket for a 1990 BII

this is very strange then - because everything I'm reading says the EGR valve is what controls the NO in the recirculated exhaust gases.

well i dropped the truck off at the shop - UGH...$83 just to find out what the problem is

The EGR gasket goes under the block plate where the EGR was in 86-87.

Ray

so they put in a new pvc valve and adjusted my timing (it was off by 5 degrees)

truck runs a helluva lot better - but still failed emissions.

He suggested I take it out and really get on the throttle to try and blow out the cat and exhaust - It had been sitting for 2 months when i bought it - and the most driving i do is stop and go traffic for about an hour a day to and from work.

anyone ever heard of that working?

Yes, it actually does more good than harm in most cases to get the rpm's up ever so often.
Keeping the vehicle in a lower gear while driving in city and obeying the speed laws will most often do the trick.
Casual driving in stop and go is an engine killer, the engine gets warm, but is not operated
at a high enough rpm to clean the carbon and other contaminates out of the cylinders and exhaust.

Ray

take it out on the interstate and

ok thanks, I just wanted to make sure i wasn't being yanked around.

In PARK, I rev'd it up to the redline, far enough for the limiter to kick in and there was a hint of black smoke that came out the tailpipe. I only did this 1 or 2 times. I don't have to open it up that high on the highway right? lol - not trying to get any tickets. I am also hearing a sound (like an old school rotary telephone ring) coming from underneath the car...it does very slightly while driving or while in park. I haven't pin pointed it yet - but my exhaust pipe needs a hanger so I'm not sure if it's just the pipe swinging around vibrating on something.

sucks i won't be able to do it this weekend - with 12 inches of snow looming in the skies scheduled for tonight into Saturday night.

oneway wrote:In PARK, I rev'd it up to the redline

rev limiter??? at what rpm's does that kick in?? iv taken one to 6000 and didnt hit it. you gotta take it out and drive it,work it,wind it up through the gears

Like Dave said,

Drive it like you stole it.. and the cops are on your ass.

It will do about 60 in 3rd gear at 6000, that won't get you a ticket on the interstate. (not where I live anyway)
Run the rpm's up to 4500-5000 in the gears, watch the speed and figure how fast you are going in each gear, you
can do that around town.
You said a hint of black smoke, that is more than likely why you can't pass emissions

Ray.

yea just my luck we get 2+ feet of snow lol....so i haven't really taken it out and floored it...but i have been accelerating hard from stops and stuff

yea rev limiter kicks in between 6k and 8k rpms - prolly more toward 8k (the range is only from 1 - 8k rpms) when I bounced it off the rev limiter, that's when I saw the hint of black smoke - it wasn't a lot at all - a small poof. This part of the emissions only takes it up to 15mph and 25mph - obviously no where near the limiter.

I think the next thing on the agenda is a new cat - but that's like $400 for part and install...I only paid $685 for the truck lol....and it's already had a full complete $800 brake job. It's an awesome truck for it's age and mileage and I baby the shit out of it lol.

had a mishap with the 4x4 - apparently I didn't read the rest of the directions in the manual - where it says the auto locking hubs may not disengage fully in cold temps (the truck was buried in snow for about a day or 2) - so I put it in 4x4 to get out...worked good...took it out of 4x4 and hit the highway..but then heard this ticking/tapping noise coming from the wheel as I was going down the highway - so I chilled and went like 35mph the entire way..ugh. Only to read the rest of the directions where it says to fully disengage the hubs, you have to take it out of 4x4 and drive backwards in a straight line for 10 feet or so. So I did that and the ticking/tapping went away....weird.

Low Range makes a ratcheting sound when it is engaging while in Neutral (per the manual - to engage only while in N)
4x4 just makes a soft double click sound - I'm assuming it works because I was able to get out of the snow on a muddy steep decline (I had to back up, up the hill to get out while the truck was half on the driveway and half on the muddy ground)