1.7 with carbs and fi cam

[VIPRKLR]

I cant pass emissions. Is this due to the act that the car has FI and the PO did not change cams? Is there a wasy to pass emissions with this setup?

Thanks

VIPRKLR
77 911 S
71 914 1.7L Rust Rocket

[This message has been edited by VIPRKLR (edited 04-30-2001).]

[Rouser]

Pardon my ignorance, but exactly what state are you in that checks emissions on a 30plus-year-old car?

The 1.7L engine comes standard with FI; what exactly are you talking about " ... the PO did not change cams?"

[Jake Raby]

The FI cam should pass with carbs, they usually run super clean...Try running super unleaded, and driving it really hard before you have it tested..

[VIPRKLR]

Rouser: no problem my friend. I live in Colorado. I only need to pass emissions one time (if I sell it, then it will be required to pass again, and so on...)

Since the car came with Fuel Injection (FI) it had cams designed for FI. I was under the impression that if you change the induction system, you need to change cams as well, but apparently I was wrong.

[DDS]

IIRC, you must change to a carb cam if switching to carbs from the stock FI if you wish to enjoy improved performance. (nothing to do with emissions per se) This is why most feel that the stock FI is the best induction system in an otherwise stock engine.


[This message has been edited by DDS (edited 04-30-2001).]

[johnboy914]

I, too live in Colorado and have had to deal with this. The biggest culprit that I have found in getting aircooled motors to pass emmisions is valve adjustment. They must be absolutely at .006. I had #3 just a hair loose on the intake and exhaust and failed at 1300 ppm, I did the valves and went through at 450ppm. Also make sure that the timing is right. At our altitude you can get away with 32 degrees at 3500rpm without running too hot. Good luck.

[rkyrdrcr]

I too am thinking of putting dual 40's on my '75 1.8. I'm not going to change the cam right now. I live in Texas so emissions won't be an issue. How does the car run with stock cam. I would have e-mailed but you didn't put address. Anyone else with input would be greatly appreciated.

[Eat-um-up]

Originally posted by rkyrdrcr:
I too am thinking of putting dual 40's on my '75 1.8. I'm not going to change the cam right now. I live in Texas so emissions won't be an issue. How does the car run with stock cam. I would have e-mailed but you didn't put address. Anyone else with input would be greatly appreciated.

I Recived my car with duel 4 dellortos on it. it too has the FI cam in it. still does. it rns just fine and has plenty of get up and get

------------------
Sweet Blue 72' 914
Check it out at
http://www.geocities.com/eat_um_up/914.html

[TimW]

[preface: sorry for the long post...]

Milwaukee (that’s in WI ) and the 6 surrounding counties still require emission checks for cars back to 1968.

You’ll find, generally speaking, swapping FI for carbs without swapping out the cam will give you poor idle and poor emissions. Frankly I’m quite surprised that with 30 years of testimonies on the subject the results aren’t more clear-cut.

I can attest to those claims first hand. After an engine fire I did that swap on a ’71 1.7L with dual Dellortos, and they never ran right. After the fact I came to find out the problem was likely the cam -- designed specifically for F.I. I might add.

BTW: This is the same claim George H. from AA touts. Regardless of what you think of AA, you have to admit George knows what he’s talking about.

Further, a buddy with a ’73 1.7L is in the same predicament as you; can’t pass emissions after the PO did the carb swap without swapping the cam -- even after having the “the pro’s” (whatever that means) tune the car before testing. His car was still putting out so many hydrocarbons the cars in the adjacent testing bays were failing! The guys spent 45min. with him trying all sorts of different things to try and get it to pass, but to no avail.

I’d tend to believe having the valves adjusted correctly would help get the engine closer to that pass mark, but I heard (maybe just a urban legend) running super unleaded and getting the engine warm won’t matter much on Type-IV’s. I think it was here actually that someone argued the virtues of running lower octane fuels since the higher octane fuel additives do little for emissions, power, etc.

I’ve also heard leaning out the injection on Type-IV’s won’t help because while you’ll pass one test on one end of the scale you’ll fail some other test on the other end. The trick is to be right in the middle so both tests will pass.

My buddies solution was to get a PO box in another county that wouldn’t require testing. I’d be really interested in knowing what you come up with so I can pass on a real solution (short of swapping out the carb).

Tim

[Scott S]

I am also in CO. My 2.0 with euro p/c's, the "appropriate" cam and dual 44's passed easily. Get a good tune up (including valve adj), put in good gas (probably more expensive than the tune up!)drive it hard, double check the tune and give it a shot. Steve's emissions (east of Kipling on 44th in Wheatridge) did a great job on mine. Then go get classic plates and call it a day!
Scott S

[TimW]

Actually, in WI where I live checking 1968 and later cars IS for classic plates.

[pbanders]

Originally posted by TimW:

I’ve also heard leaning out the injection on Type-IV’s won’t help because while you’ll pass one test on one end of the scale you’ll fail some other test on the other end. The trick is to be right in the middle so both tests will pass.
Tim

Depends on the type of emissions test you get. If they're testing for NOx, running lean will increase NOx - but as I understand it, since there weren't any fed standards for NOx prior to 1975, this shouldn't be an issue on pre-75 914's, and 75-76 914's have a cat converter which handles the NOx, even for a lean mixture.

Here in AZ, I can tell you from personal experience that with my 1970 914 w/73 2.0L engine, I can easily pass emissions with a standard FI setup. Even when I had the system totally screwed up and running rich, I could still pass by cranking the ECU knob to full lean and opening the air bleed screw to get the proper idle rpm.

Brad Anders