Can i get an opinion? BIG Decision

[TheNicky]

Ok Got the newest Pretest readings and there horrible...
This is after my carb rebuild before my oil change...

And note: I didnt plan on taking it in thinking they would smog it so i didnt prepare it
to pass...

15mph RPM Co2% Preo2% HC CO NO
------ 2761 10.83 3.45 - 263 2.81 0149


25mph
------ 2448 11.20 3.53 - 250 2.31 0618

Let me know what i should do
Or have ideas.. Please and thnks

 

[85_Ranger4x4]

What is the max of each reading it can have?

If your throttle acts sticky but isn't (the linkage doesn't hang up, but the carb is slow to respond), it sounds like your engine has found an air source to compliment the carburetor. Spray some carb cleaner or WD-40 around the base of the carb and the intake manifold, if the RPM changes you have found your problem.

It might help your idle too.

 

[TheNicky]

Ok Maxs are

---------HC's---CO---NOX
15mph---209---1.5---1499
25mph---126---1.3---1359

And i rebuilt the carb and put new gaskets on!
you still think it could be the base of the carb?

 

[mhughes165]

it could be anything, i would look into the tech library at a few things u can do to them 2.8's with junkyard available items, one of them will solve ur issue of carburation

 

[TheNicky]

I looked in the 2.8 section didnt see much...

then again i scanned through.. i will double check...

i saw basic info nothing like junkyard replacements?

Sorry dumb question

 

[85_Ranger4x4]

And i rebuilt the carb and put new gaskets on!
you still think it could be the base of the carb?

Mine was leaking at that big cardboard gasket. I don't know if you reused yours but I decided to treat them as a onetime use item from now on after fighting with mine and finding that.

 

[TheNicky]

Mine was leaking at that big cardboard gasket. I don't know if you reused yours but I decided to treat them as a onetime use item from now on after fighting with mine and finding that.

Big cardboard gasket?
I replaced the 2 at the bottom...
One on each side of the plastic spacer?

Im not 100% of which one you talking about id love to check it out tho... to see if i too have that problem
thanks 85!

 

[Shran]

I am assuming the plastic spacer. Haven't had too many problems with those, I even epoxied one that I broke back together. It was on my buddy's 81 Granada and seems to be working fine. I just replaced both gaskets...no leaks.

 

[TheNicky]

Yea my spacer was almost new...
And i got the old gasket off them with ease...

Hmmm?

Ill spray around my intake and see what happens...
Any other ideas suggestions before i start working on my truck here in the next hour?
Im ordering the o2 sensor this week from rock auto and replacing stem seals next weekend...

 

[85_Ranger4x4]

Mine had a single cardboard gasket, am pretty sure it is between the spacer and the carb. It had one on it when I got it, the carb kit came with only one when I went thru the carb a couple years ago, and last year when I tried a 2100 carb I reused it. It was slow to return to idle and idled weird, so I stuck the old 2150 back on thinking the carb was too big. The stock 2150 did the same so I started poking around and found the stupid thing was leaking. In an effort to at least get it running as good as it was before I started dinking with it I got a new gasket and it runs as good as it ever has now, and I got an itch to try the 2100 again... with a new gasket this time.

Mine has the cardboard gasket on one side of the spacer and a regular paper one under the spacer, I just kept going with the way it was when I got it.

 

[TheNicky]

Hmmm makes me wonder now?
I will look into it asap

 

[mentalbreakdown00]

Ok nicky,The low CO2 readings indicate a poor mechanical engine. You said it is noisy, check valve adjustment and check the compression, cylinder leak down test it if you find it's a little low on compression. High CO means running rich, HC's are unburnt fuel, which can be from running rich/ mechanical problems. The NOX is from running too hot, EGR inoperative or partially works, timing. Hope this helps.

 

[Shran]

OHHH that cardboard deal. I forgot about that one. My 2.8 doesn't have one, but my 302 does. Some carb kits also do not come with one.

 

[TheNicky]

Ok nicky,The low CO2 readings indicate a poor mechanical engine. You said it is noisy, check valve adjustment and check the compression, cylinder leak down test it if you find it's a little low on compression. High CO means running rich, HC's are unburnt fuel, which can be from running rich/ mechanical problems. The NOX is from running too hot, EGR inoperative or partially works, timing. Hope this helps.

Thanks Mental
Ill do the valve adjustments next weekend when my seals are in...
And Sorry for being so new but whats a cylinder leak down test?
And with engine work the HC's should drop?
With NOX is that all i need to look into? just the EGR im doing a radiator flush this weekend... the guy before me put in this leak stopper crap in there...
The timing is dead on and has a brand spankin new ignition because the mechanic broke mine and made me pay for it because it had 1 screw in it (wasnt me) but he gave me a free hr or so in labor...

Again i didnt prepare it for smog i took it in for a diagnostic and he then told me after the pretest but it gives me a good idea... so heres my Gameplan!

Compression Test
Valve Seals & Adjustments
O2 Sensor
Test or buy new EGR

Thats a good enough start for me i will report any news back here...

Thanks again for being so patient...

PS got my Test back before the truck was sold to me
HOLY CRAP numbers were doubled so looks like i have helped out alot...

 

[mentalbreakdown00]

A compression test tells you if you have good, or low compression. A cylinder leak down test will tell you where the cylinder is losing the compression, i.e. if air comes out the oil filler cap the rings are bad, out the exhaust the exhaust valve isn't sealing good, out of the intake intake valve, out of radiator, head gasket/ head. NOX is caused by cylinder temperatures being to high. This can be caused by, malfunctioning cooling system, incorrect timing ( If you set it with a light it still may be off), a bad egr valve or clogged EGR ports, and lastly by running too lean. HC's are unburnt fuel HC's meaning hydro carbons, can be caused by timing, running too rich or lean, bad catalytic converter, low compression, etc. CO is carbon monoxide and it is from running too rich. Also I think the Pre02 you posted almost has to be 02 percent, and if it's that low it's running waaay too rich and will cause you high idle and your C02 to be down and Co to be up but NOX should be down with that. Find out what you mean by Pre 02 for me.