OK, something's got to be wrong somewhere, looking for ideas on what to do....

Took my 383 SuperRam in for it's first emissions test today, and it failed, BIG TIME. It failed the HC ppm and CO percentage by so much that there has got to be a problem somewhere. Surprisingly enough, the NOx was real low, so it passed that part of the test with flying colors. Here's the test results:

AT 25MPH:
HC - <114 standard, I had 1510 (over 10x too many)
CO% - <0.63 standard, I had 4.15
CO2% - no standard, I had 10.8
O2% - no standard, I had 2.7
NOx - <798 standard, I had 115
Dilution% - >6 is standard, I had 14.5

AT 15MPH:
HC - <117 is standard, I had 1678 (over 10x too many)
CO% - <0.65 is standard, I had 3.41
CO2% - no standard, I had 11.1
O2% - no standard, I had 2.9
NOx - <879 is standard, I had 132
Dilution% - >6 is standard, I had 14.5

The cam specs aren't that radical - duration is 218I and 224E @ .050 with a 112 LSA. The RPM at these tests was all in the 1500-2100 RPM range. Car is running SLP Tri-Y headers, has 2 month old dual Catco cats, and a one month old AFS-74 heated O2 sensor. Compression is 10.5:1, and it has the FastBurn type Sportsman II cast iron heads.

So, where do I start? Surely these specs can give us a hint on what's off. I appreciate all assistance offered!


- Ye Old Phat Phart, Vern

 

NO IDEAS?!?!?

 

By the readings it appears to be running way rich. I would look at the programming especially at what percent it enters P.E.

 

like eric305TPI said, your way rich. make sure your o2 sensor is working, check the air injection, make sure it isn't injecting air into the headers once your in closed loop. is it setting any codes.
check your engine temp & both the air & coolant temp sensors. make sure the timing is right.
your CO2 is on the low side. that should come up once you get the CO down.
once you get the CO down, don't be suprized that your NOx has taken a big jump up.

 

Speed Density, you need a new PROM.

 

Well, the actual problem is that the #3 cylinder has ZERO compression, both wet and dry. My guess is that's where all the unburned fuel is coming from...

Checked the valve lash one more time just to be sure, and that's not the issue.

Can't get any compression reading on that cylinder by tightening or loosening the roller rockers unless they're loose enough to rattle. So my guess is either a valve missing a big chunk (IN WHICH CASE WHERE DID IT GO?) or a piston with a crack or hole. All on a motor with only 2300 miles. Looks like I'm driving to Houston for warranty work on this motor. Probably Wednesday.

Appreciate everyone's suggestions and replies.

I'll post the end result/post mortem once we get the head off Wednesday or Thursday.


-Ye Old Phat Phart, Vern

 

OR,
Unplug that injector and try again! LOL !
That sucks that you have to go through that on a new motor.

 

Treid unplugging that injector - the motor almost dies and sounds like its starving for fuel. Had to think on that one a bit....

My theory is that the other cylinders are living off that injector's fuel as well. Since #3 has no compression, that means it shouldn't have any vacuum to pull the fuel into the cylinder either. And since on TPI all injectors fire at the same time, essentially I think that means the fuel in the intake just "sits around" waiting for the intake valves to open and the vacuum from the piston down stroke pulls in the charge. Hence my #3 injector is actually helping the other 7 cylinders "live" so to speak.

Does this make sense?

If not, what shoudl I do?

 

I was really just kidding about trying that
From your response it seems that the valves are moving so you don't have anything stuck or flat lobe, etc.
Strange that you don't get anything on that cylinder if the valves are acting right.
There's either nothing getting in or a BIG hole in the piston.
I'd check the valves again just to see if they are moving, you don't want to fill that cylinder full of fuel and have nowhere for it to go. Air can be compressed and pushed out, liguid oviously will not be so easy to get out.
If the intake was not opening I'd think you would get readings like you have. Just pulling vacuum, then compressing back to atmospheric pressure (nothing on gauge) and fuel would puddle up and get blown around to other cylinders.
If exhaust was stuck open you would see backfires with fuel igniting.
Just thinking out loud...

Edit: Nice looking motor BTW

 

if it was a piston problem you would have a lot of blowby.
once you get it back going i would get the injectors flow tested.
you said that you didn't get anything unless the rockers were loose enough to rattle, how much did you get like that?
if you have an air compressor you can loosen both rockers on that cylinder so the valves can't open, pull the plug & hook up the air to it & see where it's leaking at.

 

DENN_SHAH - I could actually get a reading of 90-120 when the exhaust valve was rattling. I think I was getting a reading on the intake side as well, but won't swear to it. The other cylinders I've tested compression on all got more like 220 or so PSI (which is a little high probably due to the 10.5:1 compression ratio).

I'm hoping there is just a problem with the intake valve on it, will be a lot quicker for them to fix it tomorrow than having to swap a piston (assuming no cylinder damage has happened). Since the rockers are moving when I adjust the lash (doing it with the motor running), I'm afraid it's not a valve though. I agree with JP86SS, the cam sounds okay. Thanks for the compliment on the motor's looks, too. Hopefully by the end of the week it'll be running to match the looks.....

I hadn't thought about the compressed air idea. How would you seal the hole while injecting the air? Hmmm... maybe my rubber nozzle blow gun will work for that.

Right now I'm planning to drive it 4+ hours to Houston to the shop that built the motor for the warranty repair. It's been running rough for at least 4 weeks, so hopefully a 4 hour drive isn't going to hurt it any more (and hopefully it will make the drive!)

That air injection idea is a good one though, I'll have to remember that.

As well as it runs on 7 cylinders, I'm anxious to see how it will do on all of them! I'll let everyone know later this week what we find when they pull the head tomorrow. Thanks for all the replies and suggestions!


- Vern

 

i use the lower hose for my compression gage to pressure up the cylinder, it has a standard coupling on it so it plugs right into the air hose. it works like a leak down gage but without any gages.

good luck with the drive down, don't push it too hard.

 

could be a lifter (stuck - not allowing any hydraulic action - holding the valve open when "adjusted" and explaining why when it's clicking it gets pressure).
It makes sense though. If a cylinder was dead, not combusting and pumping air at the O2 sensor (#3 is on the side of the sensor), it could be sensing the air and crossing over and fooling closed loop. The HC are from that unburnt fuel from that cylinder. 4.5% fuel is around 12.7 A/F, and 3.5% is around 13.4:1.

 

hey man sorry it was me to have to fail you, hope there is nothing bad like the piston you are talking about, hope you get it all figured out soon, sweet formula.
later
-doug

 

Well, I'm back in Dallas, got in from Houston late last night.

RednGold86Z - you had the problem pegged - unfortunately we couldn't tell that until we got the intake manifold off.... but Thanks just the same!

And we found the problem.

I had TWO collapsed lifters that when the rockers were adjusted so that the valves would not rattle were so tight the valves were not closing. I knew I had a problem on cylinder #3 from my getting zero compression on that cylinder. The surprise was that #8 had a collapsed lifter as well. I never put the compression gauge on #8 because it's so d@mned tight back there with the headers, so I didn't know I had a problem with that cylinder. Apparently it was just a bad run of lifters....

So we replaced all 16 lifters with new ones. And now the motor PURRS. It's amazing how much more power it has with all 8 cylinders working properly. When I pulled out of the lot onto the service road to head back I broke the whole rear end loose and wasn't even trying!

Plus I got 20-21 MPG on the 250 mile trip back while running 75mph or so the whole way - and that was with the AC on the entire time!

Can you tell that I'm extremely happy about all this? Plus the guy I got the motor from stood behind his warranty and I didn't pay a cent for the new lifters, gaskets, etc. He even bought my lunch on Wednesday.

If anyone ever needs some good custom head work, or a drop-in motor, I highly recommend Jonathon at AM Performance Heads in Houston.

I'm still kind of babying the motor to make sure the rings seal good on #3 and #8, but the compression on #3 with the new lifters was over 240 PSI, so they're not too far off as it sits.

Now I'm ready for some really fun driving!!!!!!

- Ye Old Phat Phart, Vern

 

Its good to hear, and also you found someone who will stand behind his work.
Need more of that these days.

 

Glad everything has worked out for ya my friend...my chip should be ready in a week. Hopefully I will get a good one this time. Drop me an email about what i asked you k? I am wanting to buy a laptop this weekend from ebay and need to know what to look for.