| Author | Message | ||
| Jeremy Lawrence (F512m)
Junior Member Username: F512m Post Number: 179 Registered: 1-2002 |
Spent some time with JR today looking into the emissions on the QV. We narrowed it down to the Frequency valve, as it is not humming. I listened to a FV on a 328, then mine. Major difference. The 328 was humming like a champ while mine was not hummming at all. Jr is ordering a new FV and we will be installing it when it arrives. Thank you JR for allowing me to pick your brain on a few issues, as well as taking the time to explain things, and helping me understand how my baby works. This is fun!! JL | ||
| Jeremy Lawrence (F512m)
Junior Member Username: F512m Post Number: 178 Registered: 1-2002 |
That is exactly what JR said. The Frequency Valve is not "hummimg" so that may be the problem. I will update tomorrow after the checkup. JL | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 534 Registered: 4-2003 |
An engine miss fire due to an open plug wire (off in this case) would cause a much higher HC level. How could that explain an 8% CO?? Remeber, CO=unburned gas in the cylinders, while HC=unburned gas from the tail pipe. In general CO is carb/fule injection related. | ||
| Jeremy Lawrence (F512m)
Junior Member Username: F512m Post Number: 177 Registered: 1-2002 |
While looking the engine over tonight, I discovered that the #1 plug boot was not pushed all the way down. I pushed it down and felt it snap into place. Could this be the cause of it running rich? It seems to me that if #1 wasn't firing, the raw fuel being sent into the exhaust would make you think it was running rich, and make the numbers be way off. But, I could be wrong... JL | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2132 Registered: 11-2002 |
>>If this is possible, then one could test it by unplugging the harness to the frequency valve while the engine is running. << Point is this...it's only neccesary to know if the frequency valve is working or not. If it is it leads in one direction of diagnoisis, based on the symptoms, if it's not it leads in another direction. I believe when the final conclusions are in it will turn out to be the Lambda System or one of it's components...based on the symptoms descibed... Besides before everything is said and done the feedback system will get looked at whether anyone wants to or not...so why not start by listening for an audible humming noise right off the bat instead of throwing a myriad of wild guess's into the wind. An example: if you start your engine and it has no oil pressure do you first remove the engine and replace the oil pump or check the oil level on the dip stick? | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 505 Registered: 4-2003 |
The reasons for a rich air/fuel mixture are almost infinite. Years ago I saw a BMW 318 with an intermitent cold start valve that was leaking. The Temp/time switch was fine the cold start valve it self would drip from time to time. Talk about chasing gremlins. | ||
| Joe Craven (Rscapri2600)
New member Username: Rscapri2600 Post Number: 24 Registered: 7-2002 |
P. Thomas, I don't think that our mid 80s cars had check engine lights for these items. JRV, I thought about your comment a bit and the only situation I can think of that fits your situation is if the Lambda computer causes the frequency valve to stay in the open position, causing the fuel pressure to drop in the lower chamber of the fuel distributor thereby increasing the fuel to the injectors. If this is possible, then one could test it by unplugging the harness to the frequency valve while the engine is running. 1) confirm that the frequency valve is humming or buzzing. If it is not, something is wrong. 2) If it isn't buzzing, unplug the harness and the engine should keep running the same. If it starts stumbling and runs awful, then I would think that the frequency valve is being kept open by the Lambda computer. Good luck and curious to hear what is causing the over rich condition. 85 Mondial QV | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 501 Registered: 4-2003 |
If the lamda stopped working, or any closed loop emission related component ( map sensor, crank position sensor, speed sensor, etc, etc), wouldn't that trip a Check Engine Light. In Cali that is an upfront automatic fail and they will not even hook it up to the sniffer. He does not have a check engine light on...Right? | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2128 Registered: 11-2002 |
>>If the frequency valve stops working, the CIS system goes way lean. << Not if it's the Lambda Computer causing it to stop working. {  } | ||
| Joe Craven (Rscapri2600)
New member Username: Rscapri2600 Post Number: 23 Registered: 7-2002 |
If the frequency valve stops working, the CIS system goes way lean. I'm wondering if you have a bad injector. I just thought of another thing. The warm up regulator controls the pressure to the top of the fuel distributor. If the control pressure is too low, then the fuel mixture can get too rich. I actually modified the warm up regulator on my VW CIS system on one of my race cars. I move the regulator away from the engine and hooked up 12 volts to it through a rheostat. I'm now able to adjust my fuel mixture from the driver's seat and even make my car so rich that it loses 20% of it's power. 85 Mondial QV | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2125 Registered: 11-2002 |
Open the engine lid, look right of center for the Fuel Distributor (piece Air Cleaner sits on), now look at all the fuel lines on top of the FD, now look just left to the side of the Fuel Distrib, there will be a little black electronic injector w/a wiring harness plugged into it...when the engine is running it must Hummmm...insure it's plugged in also...and jiggle the plug to test for loose contacts. | ||
| Jeremy Lawrence (F512m)
Junior Member Username: F512m Post Number: 174 Registered: 1-2002 |
Thanks JR. Where is the FV? Where do I listen for the humming? | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2124 Registered: 11-2002 |
Sounds like the Lamda Computer is out of commision. CIS systems don't even run @ 7%-8% CO full rich when cold. You need to see if the frequency valve is humming. If not there's your problem. | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 497 Registered: 4-2003 |
FYI, one way to lower the HC reading is by retarding the ignition timing. careful, in California they check that as part of the emission test. Plus with the loss of power it also could cause your car to overheat. | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 493 Registered: 4-2003 |
CO (Carbon Monoxide) is unburned gas in the cylinders. HC (Hydrocarbons) are unburned gas coming from the tail pipe. Your CO is sky high. This is due to a rich air/fuel mixture. A high CO will also cause a high HC reading. With the CO so high, if you also had a misfire the HC reading would be way higher than what you are getting. At this juncture, provided all of the smog equiptment is on the vehicle and operating correctly, the engine needs to be leaned out. | ||
| Joe Craven (Rscapri2600)
New member Username: Rscapri2600 Post Number: 22 Registered: 7-2002 |
Jeremy, I did a search of Houston emissions testing and it appears that testing in Texas is as aggressive as what is happening in California. I noticed that they have a low mileage waiver, for people who drive less than 5000 miles since their last inspection. Wow, the 15mph test is using 50% of the cars available power. 25mph test uses 25% of available power. The normal CIS idle mixture doesn't affect fuel mixture too much in the ranges where this emissions test is getting accomplished. These Bosch K-CIS systems are designed to maximize a rich fuel mixture by upping the frequency valve to some predefined value when either the full throttle switch is engaged or O2 sensor goes open loop. Since maximum power for most engines is about 4 to 6% CO under full throttle, your motor is putting out way more than that which is even getting measured after your catalytic converter. Hmmm, I would think your catalytic converter is missing or damaged at a minimum. The HC is usually excessive if there is a misfire in the cylinders. I'm wondering if you have a plug wire going bad too. I just replaced an open circuit wire on my Mondial a week ago. 85 Mondial QV | ||
| Philip Airey (Pma1010)
Member Username: Pma1010 Post Number: 343 Registered: 7-2002 |
Jeremy If I am interpreting your data right it is way rich at both (modest) test speeds. Others should opine based on experience with the 512, but I'd start looking at why it is reportedly so rich. When this occured to me on a fuel injected car in the past, it was generally one of three elements. - The O2 sensor being bad - THe cat (or cats) gone south after a lot of rich running (likely caused by #1) - Wrong plugs I've also had a failure due to a leaky injector. Plugs are an easy check. A shop ought to be able to look at the O2 sensor output and see if it is reading across the range and trying to get it to idle around stoich which is where I'd start. For the cat, check the presence of the honeycomb. HTH | ||
| Steve Magnusson (91tr)
Intermediate Member Username: 91tr Post Number: 1997 Registered: 1-2001 |
Jeremy -- Are you sure the cat is intact/present? (7~8% CO after-cat is way high -- should be ~0.8% CO before-cat) Is the O2 sensor hooked up? Is it generally running OKish (i.e. -- no missing)? If so, either: 1. the open-loop tweak is so wacky rich that the closed-loop components (when active) can't compensate, or 2. something in the closed-loop part of the system (O2 sensor, lambda valve, ECU, etc.) is frazzled. If you've got a multi-meter, just measuring the quasi-DC voltage coming from the O2 sensor can be useful sometimes -- both when plugged-in and idling (warm) closed-loop (it should be banging about between ~0.1V to ~1.0V) or when unplugged and idling (warm) open-loop (it should be fairly constant in the 0.6V~0.9V range) {cold O2 sensors give no useful signal}. Do an internet search on "Bosch K-Jetronic with lambda" to get background information on how the closed-loop K-Jet with lambda system works. (If someone has a good Bosch CIS link handy please post.) | ||
| Jeremy Lawrence (F512m)
Junior Member Username: F512m Post Number: 173 Registered: 1-2002 |
The reading are: High Speed (25mph) Low speed (15mph) Std. Curr Std. Curr. HC(ppm): 137 195 140 233 F CO(%): 0.87 8.10 0.79 7.20 F CO2(%): - 9.4 - 8.8 O2(%): - 0.5 - 2.7 Nox(ppm): 956 109 1046 96 P Dilution: >6.0 17.5 >6.0 16 P | ||
| dave handa (Davehanda)
Intermediate Member Username: Davehanda Post Number: 1505 Registered: 5-2001 |
What are the readings? You probably need the mixture adjusted by someone with an exhaust analyzer. I doubt that Techron will make any difference. I know that stuff in the bottle called "garanteed to pass" really works (or so many have claimed), but if the car is way off, you really should get it set up right. | ||
| Jeremy Lawrence (F512m)
Junior Member Username: F512m Post Number: 172 Registered: 1-2002 |
She didn't pass!!!!! Any idea what could be wrong? I will change the spark plugs tonight. But don't know where else to look. I have run 4-5 bottles of Techron on the drive over from Florida so the engine should be clean. What next? |