Need a smog doc, stat!

[neil30076]

My 1984 Euro S refresh project, first time driven in over 2 years, just refreshed everything top side of engine, hold vacuum perfectly, no leaks , etc, etc.
Failed smog on high NO ( see attached).
I'm getting ready to hook up the LM-1 and CO tester, high NO with other readings in range suggests it is set to lean, anyone have an opinion.

[XLR8928]

Are you sure the O2 sensor is good?

[neil30076]

Originally Posted by XLR8928

Are you sure the O2 sensor is good?

There is no O2 sensor - its an open loop system!

[dr bob]

Neil--

Hope you can read my RL comment. Plus, you may want to look and be sure you have copper plugs (no plats or silver), and maybe one or two steps colder than original. Plats are typically a hotter tip compared with copper of the same heat range so theycan be self-cleaning; the plat is more durable so the high tip temp is what they are designed to do. Then drive the car long and hard, the proverbial Italian Tune-Up, to get any oil resdue in the intake flushed through and out before you test. Roll it right oto the rolers when you get there, so no parking-lot cool-down of the cats.

[MPDano]

Hi Neil,

Here is my results after putting a new Cat and it was running Super "Lean" when tested. It doesn't seem that your issue is a Lean A/F. Are you sure it wasn't "Rich?"

[Mrmerlin]

you may need to reset the MAF
IIRC a setting of 167 ohms or so seemed to make the car run well you can check the MAF setting at the computer connection
get on RL and search for MAF setting by PORKEN

[MPDano]

Originally Posted by Mrmerlin

you may need to reset the MAF
IIRC a setting of 167 ohms or so seemed to make the car run well you can check the MAF setting at the computer connection
get on RL and search for MAF setting by PORKEN

Oh Boy, if I recall, this is reason for the great deal on this particular 928. It had a MAF issue. I sure hope you can sort this out Neil.

Also, isn't this for your Air Force Daughter? If so, check the Smog Requirements (if any) in the State she is Stationed at.

[neil30076]

Thanks everyone, yes Dr B, I check the RL post -
- Leo, yes the car was a great deal beacuse of the smog failure, and they handed me a new - yes new - MAF that they had not installed! And yes, no smog check where the car is going, so not so critical - but i would like it to pass anyway :-)
. Stan, the old MAF setting was around 470, the new one is set s 700 - so some more investigaiton is needed, as soon as i get the AFR meter set up i'll have a better idea.
thanks all for your commenst, i'll report back.

[neil30076]

Update - I have the wideband O2 sensor and LM-1 ( Innovate) installed - ran until at normal temp, at idle AFR is right on 14.7. As soon as i open up on the gas it jumps up to around 16.2 way lean -- off gas - back below 14 .3 for a second or so, then right back to 14.7. Swapped out MAF with a new one PO gave me, and exactly the same, MAF adjustment is now right at max - 1,000 ohms. Put my vacuum gauge on vac lines, holding good when idling, drops of course when i hit the gas, but comes right back - gas sniffer ( gunson) says 3.5%.
Whats next?

[MPDano]

Originally Posted by neil30076

Update - I have the wideband O2 sensor and LM-1 ( Innovate) installed - ran until at normal temp, at idle AFR is right on 14.7. As soon as i open up on the gas it jumps up to around 16.2 way lean -- off gas - back below 14 .3 for a second or so, then right back to 14.7. Swapped out MAF with a new one PO gave me, and exactly the same, MAF adjustment is now right at max - 1,000 ohms. Put my vacuum gauge on vac lines, holding good when idling, drops of course when i hit the gas, but comes right back - gas sniffer ( gunson) says 3.5%.
Whats next?

Mine does the same as far as lean at higher rpms, but I have CIS so I expected it to not be a very precise system. Did you get the Digital Gauge too?

[neil30076]

Leo, I have the whole setup - multi channel input, rpm adapter, thermocouples, logger, digital display -etc- I can see it jumping around in real time and also damped so it's a more readable value.
The car runs like a rocket, easily spins wheels on take off - and lots of power, I'm concerned about the lean condition at anything other that idle - that's my main focus right now.

[Mrmerlin]

what happens when you adjust the MAF to about 170 ohms??

[neil30076]

As i adjust the maf resistance down it gets much worse - goes to about 17.5:1, starts to run really rough and stumbles as i give it gas.
I noticed the plugs are W8DC's, i recall a euro should have w7's - can that be the problem - plugs not hot enough?

[neil30076]

How do you check the timiing on a dual dizzy Auto 84 Euro? The smog check says the timing was 21deg - but doesn't say at what RPM.

[bwmac]

well I hope I don't sound new, but I am to these cars so take what I say as just trying to throw some ideas out there.

If you run more advance on the timing your NO would get worse, correct?
I believe a real hot burn produces more NO
If the timing can be retarded to say 19 from the 21 (that must be full advance BTW) it may help
second thought
If this is a problem car or a problem from before ..... has anyone put the wrong control unit in it (ECM)

I'm sure you guys have thought of all this anyway.
Seems like some well experienced post
maybe I stirred some other thought

[Danglerb]

Dual Dist makes no difference, timing is "set" by the brain using a crank sensor, just put the pickup clip on the cylinder 1 wire and read the marking on the dampener. Use the rpm etc required for your model.

[neil30076]

Originally Posted by Danglerb

Dual Dist makes no difference, timing is "set" by the brain using a crank sensor, just put the pickup clip on the cylinder 1 wire and read the marking on the dampener. Use the rpm etc required for your model.

thats what i assumed - I've checked all my usual sources, but still looking for the correct advance @ ? rpm for a 84 Euro - anyone?

[MPDano]

Neil, is this L-Jet?

[neil30076]

Originally Posted by MPDano

Neil, is this L-Jet?

leo, yes it is -

[Danglerb]

84 Euro is LH not L, off the top of my head about 10 BTDC at idle.