HC a little higher, and NOx too! '81 Scirocco

Woodchuck, is that _you_?

Good to see you still on the side of the Angels.

TBerk

Yep, still here.

Woodchuck, is that _you_?

Good to see you still on the side of the Angels.

TBerk

Besides a slight vacuum leak around injectors ("but not enough to cause NOx to be so high") my mechanic found no reason for high numbers. But when he got a 'pre-test' check, both HC and NOx have now gone even higher - into the 'gross polluter' range.

The tester says: "install a new CAT and O2 sensor." After checking price locally, I ordered both from an online seller who 'discovered' after a couple of days they were out of stock on the CAT.

I'm still unclear as to how both HC and NOx can be rising with each test. Mechanic says he'd suspect the EGR if the engine had one. (What is clear, though, is that my mechanic does not want to work on this car anymore. Can't blame him when the only time I ask him to work on the car is when it becomes a pain in the patootie to figure out what's going on without spending $100s.)

Thinking about possibles, I wonder if leakage from the cold start valve could be a culprit. At >$150 for replacement, I hope not.

nf

Take care of ALL problems when you find them! So if there is a vacuum leak at the injectors.........change those seals or reseal those injector seats.

The CO might be too low which could raise both the HC and NOx. How is that being adjusted, and what is it set to? Fuel Distributor Plate properly set? What is the ignition timing set to? Have all of the distributor advance mechanisms been checked? I think yours has three, one mechanical, one vacuum retard and one vacuum advance. Has the camshaft timing been checked? I have even seen a problem when the timing belt tensioner turned CCW.

I have gotten a Jetta running on 3 cylinders to pass just barely, but it did finally pass. It really needed engine work and TG was retired before the next emission test. I had to plug up one of the injectors to shut down that bad cylinder.

Cold start valves can easily be tested and they should not cost $150! :-)

start valve could be a culprit. At >$150 for replacement,

I if you want one I should have a brand new one in my parts stock.

Is the removal/reinstall of injectors as simple as it looks from the manual?

Well, maybe I have the wrong mechanic for this. He doesn't have an exhaust gas analyzer. The smog check guy has the state-approved smog check equipment. I know he was messing with the CO because when I picked up the car it wouldn't idle. He came out with an allen wrench and adjusted CO about a quarter turn higher (clockwise). I called my mechanic and he said he did not mess with the CO.

I checked this 2 years ago. Will do so again.

This is checked as part of the state smog check: 3 ATC.

I recall I checked 2 yrs ago and all were working. Will take another look.

It's been about 11 yrs, 40K mi, since belt and maybe 20 yrs, 150K mi, since belt & tensioner were replaced. I don't hear any noise from the belt/tensioner.

As I've said before, this engine seems to be running pretty smooth, with good torque. I've avoided running to redline but I'm sure it will. Don't see smoke from the exhaust.

Here's a lower price, but not by much:

The Clymer manual shows a reasonably easy test assuming I can make a proper fused jumper wire, but no indication whether a new gasket/seal is required.

Thanks again for taking the time to consider this.

nf

If you have to ask then it is real difficult. :-) A Bentley manual is far superior to a Clymer, I think. Sometimes the injectors are hard to remove even with the puller. New orings soaked in gas for a bit. Personally I spray some Triflow on the seals as the gas does no seem to work so swell for me. You may try it when the engine is hot as things might be slightly more flexible. But your fingers hurt without good gloves. You remove the injectors. I personally remove the injector buckets replacing those that are damaged. You reinstall using proper Loctite. I cannot find the section in the book that specifies the proper Loctite. Loctite has two roles. One to reduce the chances of the bucket getting loose. Second is to seal up air leaks. Those injector buckets come out with an 8 or 10 mm allen wrench. Sometimes the buckets are all broken up allowing false air.

Ideally you adjust the CO with the allen wrench and a mixture sniffer stuck >

The extent of Clymer instruction is: "Remove a fuel injector." I got the impression you just unscrewed the hex top and whistled and it came right out.

"I need a puller," I mumble, and feel a rustling in my wallet as more $$$ prepare to leave.

It seems the trepidation I felt about testing injectors as described in Clymer was justified.

Thanks for the info.

nf

Yep a puller, and they don't cost that much, is very helpful!

Like Jim said, your mechanic can use a Dwell Meter to adjust CO. The paper Bentley will outline instructions better.

2 years ago? did it have problems then or did it pass! :-) 2 years ago? did it have problems then or did it pass! :-) If the advance/retard is not working properly then that could cause part of the problem. I just had to replace the vacuum advance on my '83 GTi 1.8 engine in my '83 Audi 4000S since it was not functioning. I also apply a couple of drops of motor oil to the middle felt to keep the distributor shaft lubed so the mechanical advance can function easily. The innards of my distributor looked super clean. ;-)

OMG that is way too much $$$ for that little injector!!!

Testing it to see if it works is good, but you only need to see if it leaks fuel into the intake while the engine is running.

The bottom line is that the government probably does not want any of the older cars running on the road anymore. :-( good luck with this problem!

This is one of my regular parts vendors. Well given that I buy filters in 6 or 8 packs I don't have much cause to order parts but they are one of 4 vendors I shop with. Since I am on the east coast I try to order from folks on my side of the Mississippi. There are west coast vendors. Another of my favorite vendors. I have other favorite vendors for my TDI but that would be off topic.

Yeah, I looked around and found one for about $40 and another for $7.

As I wrote previously, after some work engine passed easily 2 yrs/3300 miles ago. CAT is 4 yrs old.

Good point on testing the cold start valve. Starting's no problem, so I'll just unbolt it from warm engine, cover hole, restart and see if it drips.

nf