Emissions Testing

[anupaum]

Hello everyone!

I'm NOT happy about having to choose between two forums and would far prefer that people in higher positions work their differences out like men.

Aside from this, my bi-annual emissions test is coming up. I've been running the same plug wires for three or four years now, and with the MESS I'd made of my coil wiring because of the misinformation concerning DIS with Megasquirt, ( ) I decided to repair the coil wiring, swap plug wires, change the spark plugs and check everything else out.

I've uncovered several issues. The first is that the nebulous intake tube that I've fashioned (which consists of a 90 degree rubber plumbing elbow fitted internally with aluminum tubing cut to keep it structurally sound under vacuum) has failed. One of the aluminum pieces tumbled through the intake tube and actually got jammed into the factory throttle plate actuator shaft. (I've long since removed the throttle plate, but the shaft that's connected to the throttle cable remains in place, and obviously that's a GOOD thing!) Also, the rubber plug I'd inserted into the PCV fitting on the bottom of the non-functioning throttle body has worn out. I had a bit of a vacuum leak there, so THAT had to be replaced.

I took off the upper intake manifold, cleaned out the EGR passage (which wasn't really that dirty) and applied vacuum to its control valve to verify function. I also removed and replaced the spark plugs on the driver's side, where I discovered that the #3 plug had been sitting in a pile of rusty sludge. The plug electrode was white on that side, but looked normal on the other half of the head.

I cleaned all of that out, but it's clear that I'll need to keep an eye on that #3 cylinder . . .

With new wires, plugs in all holes and repaired vacuum leaks the engine runs really well. (It wasn't running badly before, but this will be my first time through an emissions test with Megasquirt, so I have to do this right!) I've got to re-set my TPS value, though, because the cable had stretched and I tightened it up. Therefore, it wants to idle higher than it should and the overrun cutoff is acting a little funny.

I also wanted to recalibrate my O2 sensor, but I can't get it out of the exhaust! (Bad words . . . )

I STILL don't have the blower reconnected because I've had a few set backs. With time my bracketry had bent out of alignment, so I had a plate with slots welded onto the back blower mount. In this way I can adjust the plane of the blower pulley relative to those of the engine, but the M90 has a "hump" on its belly that raises the entire blower up a couple of centimeters. I'll have to get that plate partially cut out so I can get the blower mounted properly.

Also, the friend who was supposed to fabricate a throttle cable mount for me has been too busy to do it. I have a collection of mandrel bent 2.25 inch intake tubing that will have to be cut to fit, and I still have to figure out how to plumb the bypass valve in. Hopefully these issues will be resolved soon, but as usual, money is tight, so I just can't go to a fabricating shop and have the work done for me.

Why didn't I take metal work in high school???

robert

 

[ILLEGALCONCEPTS]

Well don't give up now Robert. It's getting closer than you think. I at least have Dave close enough for a drive if I get really stuck or just need advice. You'll get there.......

James

 

[anupaum]

Well don't give up now Robert. It's getting closer than you think. I at least have Dave close enough for a drive if I get really stuck or just need advice. You'll get there.......

James

I do appreciate your support, James.

There's a money aspect involved in this, too. I've had no new clients since June and it's tough to spend money on the truck when I've got no income coming in . . . I don't want to complain, but if I didn't have to PAY someone for fabricating because I was able to do it myself, this would save me right now!

The TPS sensor is acting strangely now. For some odd reason it's not going into overrun at all, and I'm wondering if I've got a kink or some binding in my throttle cable.

robert

 

[Dave R]

I STILL don't have the blower reconnected because I've had a few set backs. With time my bracketry had bent out of alignment, so I had a plate with slots welded onto the back blower mount. In this way I can adjust the plane of the blower pulley relative to those of the engine, but the M90 has a "hump" on its belly that raises the entire blower up a couple of centimeters. I'll have to get that plate partially cut out so I can get the blower mounted properly.

Do you have enough vertical room to just put small spacers under the supercharger's mounting points? I'm thinking of basically just a few washers, say a cm's worth, to allow the 'hump' to clear the plate. A dedicated plate that picks up all 3 mounting points would be better but the washers/spacers would work for now.

 

[anupaum]

Do you have enough vertical room to just put small spacers under the supercharger's mounting points? I'm thinking of basically just a few washers, say a cm's worth, to allow the 'hump' to clear the plate. A dedicated plate that picks up all 3 mounting points would be better but the washers/spacers would work for now.

I've looked at that option. Raising the blower works, but then the discharge tube will be too high and I won't be able to shut the hood! Also, that would increase the length of the serpentine belt, so raising the blower will create more problems than it solves . . .

robert

 

[Dave R]

A cm is too much?

Damn that is close then.

I'll ponder but you you will probably have to modify the existing plate then. Too bad shipping would be so much, otherwise you could send it down here.

 

[anupaum]

A cm is too much?

The hood WILL close if I raise the blower, but then the intake tube / throttle body combo (which will now tuck just underneath the RH fender) won't clear the hood.

Damn that is close then.

Yeah, I started out with all this room, but things have become very crowded underneath the hood!

I'll ponder but you you will probably have to modify the existing plate then. Too bad shipping would be so much, otherwise you could send it down here.

Cutting the plate to accomodate the back side of the blower is probably the easiest and simplest thing to do. I've been away taking a math course this last week, and now that I'll be able to offer this to students I'm hoping it will do something positive for my monthly revenue . . . As soon as I get some money happening I'll get the plate cut.

On a different note, I went to the wrecking yard and picked up another throttle cable. After attaching it and making the requisite adjustments, the throttle seems to be working properly again. Now, however, there are a couple of spots in the table that don't feel quite right. I'll have to fix those before I take the truck in for testing next week. Once I've gone through the process, I'll report the results here!

 

[anupaum]

Just to update everyone, I took my truck through the emissions testing for the first time using Megasquirt as my ECU this afternoon. Here are the results in grams / kilometer:

Pollutant Max Allowed My Truck

Hydrocarbons: 0.99 0.58

CO 12.43 7.76

NOx 1.55 1.06

--------------------------------------------------

I can't find my results from last time I went through, but I'm fairly pleased that I've tuned this thing well enough to get it through the testing using only a wideband sensor and a "seat of the pants" technique for ignition advance and acceleration enrichment.

 

[TireIron]

awesome man, yea you were WAY up there in emissions when you went through just after hooking the blower up. I'm actually month overdue for my sticker as I'm afraid of the emissions this year. We have to do them every other year so I didn't have to worry about it last year, and the year after I failed first and managed to just squeak by with tuning a few things up and going there with new parts. Unfortunately there is only so much a tune up can clean up and I'm afriad I may not be able to squeak it by this year. They should have mileage exclusions, it's unfair that my 341,000 mile engine should need to be at the same level as a 0 mileage engine hehe.

The only issue I seemed to be high on is the HC emissions. I was below on the CO and NOx levels so if it is the same this time I guess I will need to figure out how to lower my HC output and what exactly makes it jump higher in the first place.

Sometimes I wish I had an OBD2 vehicle as they just plug it into the computer and as long as it says the emissions are fine they leave it alone and pass it. But on the OBD1 vehicles of course they have to actually stick it on the rolling dyno and slam my tranny through the gears...

 

[anupaum]

awesome man, yea you were WAY up there in emissions when you went through just after hooking the blower up.

That was because of the off-idle bog / stall issue that eventually motivated my transition to Megasquirt.

I'm actually month overdue for my sticker as I'm afraid of the emissions this year.

We can't register or insure our vehicles up here unless they've gone through emissions testing first. Anything older than 1992 has to go through an annual inspection. From 1992 - 2005 it's every other year. Newer cars are tested every five years, and ULEV's, like my hybrid Camry, don't have to be tested for seven years!

We have to do them every other year so I didn't have to worry about it last year, and the year after I failed first and managed to just squeak by with tuning a few things up and going there with new parts. Unfortunately there is only so much a tune up can clean up and I'm afriad I may not be able to squeak it by this year. They should have mileage exclusions, it's unfair that my 341,000 mile engine should need to be at the same level as a 0 mileage engine hehe.

It's probably not the same. We have a sliding scale up here that gradually increases as the vehicle gets older. While my truck would have been considered VERY clean-burning back in the '80's, compared to most of the vehicles of similar age it's running nearly twice the HC's and about 15% higher in CO. NOx is roughly 30% higher than average, too. (That's likely because my advance curve is so fat, and the VE bins are leaned out at cruise for maximum fuel economy. In addition, the V3 Megasquirt doesn't have the resolution that the factory computer has. So I'm probably doing pretty well, all things considered.)

But my tune isn't perfect, and the guy who was driving it on the dyno had a really hard time keeping it within the parameters of the test. I'm sure that with some patience (and access to a dyno) I could get a better tune than the one I have.

The only issue I seemed to be high on is the HC emissions. I was below on the CO and NOx levels so if it is the same this time I guess I will need to figure out how to lower my HC output and what exactly makes it jump higher in the first place.

Retard your timing by 5 degrees and it will make a big difference. I didn't do that, but I COULD have if I'd not made it through the test with a passing score. Backing off on the timing results in a slightly longer burn time, which aids the catalytic convertor and will knock your HC's down.

Sometimes I wish I had an OBD2 vehicle as they just plug it into the computer and as long as it says the emissions are fine they leave it alone and pass it. But on the OBD1 vehicles of course they have to actually stick it on the rolling dyno and slam my tranny through the gears...

Yes, but then it's a little harder to get away with modifying things when your vehicle is OBD2!

 

[Dave R]

Congratulations Robert.

Down here that would be considered passing with flying colors. Glad I never have to go through a sniffer test.

 

[TireIron]

now woudl retarding the timing some cause any issues with the CO or NOx results? because if thats the case I can just pull the octane plug which should retard the timing a little bit to help with the HC output correct? Seeing as there really is no other way to change the timing on these engines without doing some major work.

 

[anupaum]

now woudl retarding the timing some cause any issues with the CO or NOx results? because if thats the case I can just pull the octane plug which should retard the timing a little bit to help with the HC output correct? Seeing as there really is no other way to change the timing on these engines without doing some major work.

Knocking back your timing tends to reduce ALL emissions. Leaning out your mixture HC's and CO, but the latter more than the former.

Pull the octane plug and see what happens!

I've obviously become so absorbed in my own project that I've forgotten that you CAN'T adjust your timing or A/F ratio . . .

 

[anupaum]

Here's the history of my truck's emissions testing since they've gone to gm / km:

year HC CO NOx

2007 0.58 7.76 1.06

2005b 0.30 6.20 0.43

2005a 1.77 21.12 0.83

2003 0.69 8.34 0.91

2001 0.25 1.20 0.14

The 2007 readings are the result of my own tune with Megasquirt, a wideband O2 sensor and no blower attached. The 2005b readings are with the factory computer, with NO blower attached. The 2005a readings resulted from the bog / stall issue I had after hooking up the intercooler. The 2003 readings are the factory computer, blower with NO intercooler (but a LOT of detonation!). My 2001 readings are pre-blower.

It's pretty obvious that it's not burning nearly as clean as it did before I put on the bigger injectors and the supercharger, but I wonder how well my catalytic convertor is operating after all of this messing around with A / F ratios. In addition, I've got a LOT of advance programmed into this engine and that's sure to reduce the efficacy of the cat!

 

[Pt_Ranger_V8]

looking good man - what are the limits where you're at?