76 280 wont pass cal smog too rich!

[70 Cam Guy]

I have scans of the pinouts, year by year, but I doubt if the ECU would have been changed. In California, the emissions control setup has to be what the car originally came with not what the engine came out of. (I hope that makes sense)

If the engine came from later model, I am pretty sure you can use the engine controls for the newer engine.

Someone swapping a KA twin cam into a single cam S13 would use the twin cam computer to run and smog the car. I know that's apples and oranges but from what you guys are saying, they made some major revisions to the L28 FI as they went

I guess it's hard to know what to recommend without knowing what he's working with

[70 Cam Guy]

ok, i did new ngk's, new wires, new cap and rotor, changed oil, filter, air filter, and put injector cleaner. i drove it for 1hr and took it to the smog station and the readings were about the same 1 or 2 numbers difference, but still a gross polluter. he even let me disconnect the #5 injector it actually was worse thenwith it connected. i'll try the timing and air/fuel ratio and as for the cat the muffler shop next door said the cat wont change the number of hc that thing was putting out and that would be a waste of money.

If the engine is running that rich, do not buy a new cat yet. An overly rich running condition will overheat and burn up a new cat. When it's running properly, then think about a new cat

[conedodger]

Well, if the HC numbers are worse with the injector plug removed we can be fairly sure that your injectors are leaking. Pull them, send the to Marren or RC and get them cleaned and blueprinted. Put new seals in afterward.

[Pomorza]

Yup if you unplugged the injector and the numbers grew worse that's a good sign that the injectors are leaking. As mentioned above send them to out and get them cleaned and rebuilt. You could take the more expensive road and opt to buy new ones but its more expensive.

Jan

[sblake01]

I don't agree with that. If they're leaking, they're leaking. Even uplugged they're still under pressure. The plug just gives it a signal.

[Pomorza]

I don't agree with that. If they're leaking, they're leaking. Even uplugged they're still under pressure. The plug just gives it a signal.

Blake I would say your theory maybe right now that I think about it. If the injector is leaking being unplugged shouldn't change the numbers that drastically. For what I remember the easiest way to check if they function properly is to do a electrical test on them correct?

My advise would still be to get the timing down and see where the a/f ratio is. It is possible that someone had "fun" with the AFM and changed the a/f ratio or the box is defective in some manner. You did also look at the water temp sensor and all the other electrical components that effect fuel injection correct? These things can affect your emissions just as much as a bad a/f ration.

Jan

[sblake01]

Blake I would say your theory maybe right now that I think about it. If the injector is leaking being unplugged shouldn't change the numbers that drastically. For what I remember the easiest way to check if they function properly is to do a electrical test on them correct?

The electrical test will tell you whether or not the injector is opening (and closing) by the 'click'. There still could be crud in it causing it to not close comeletely and it would leak. Best way is to pull it and pressure test it which requires a couple of tools that most people don't have. I have the tools but unless you plan to do a lot of work with injectors (which I have over the years) it would be cheaper to have them cleaned rather than buy the test/cleaning equipment.

[conedodger]

My theory is that if there is not electrical signal to them they should not be squirting any pattern at all and no fuel should flow. Even if they are leaking unplugging should get you less, not more HC. He unplugged and it got worse. So, with no pattern he is still getting fuel into the #5 cylinder. Dribbling fuel with a poor pattern doesn't burn.

Anyway, as I said, what do I know - It has been years since I had an L28 motor. I am just following a logic path.

[sblake01]

Not trying to be obtuse but at 36+psi, I'm not sure it would just dribble. What I wonder is, let's say the injector is good, what effect does an essentially 'dead' cylinder, which is what it would become if unplugged, have on emissions readings?