I got it back together after tearing down to heads (did not pull heads though). It runs very rough at idle and has lots of popping out carbs. the smog equipment was removed long ago but kept. I want to put back in to register in California. Looking for advice if this is something to be tacked in the garage or to send out to shop. If shop, any recommendations in LA area. total mileage is 51k mi and wondering if I should pull the heads to get valve job done? Compression isn’t bad and did see big jump with added oil. Leak down is little rough at 25%. A few cylinders have wet black plugs along with the raw fuel smell - seems to indicate possible valve issue. in order to register I need the smog and it seems like a job in itself to put the exhaust manifolds on. Wonder if it is one of those while ur in there. Attached video of running about as low it can go without stalling. Lots of popping out carbs.
You can tackle it yourself if you have the skills. You seem to have the right equipment. Although, if leak down is 25% it might not pass emission at all but it's worth it to give it a try. I know of a local owner who swaps out main jets and idle jets to leaner ones before each test, as well as installing cat converters before each test. It does pass.
Do you know if the smog pump is installed on their vehicle or does it pass without? Seems a few threads on here about people passing smog without the equipment installed. However, I agree right now doubt it would pass even with the cats and jets swap.
Smog pump is re-installed, with a belt, and associated plumbing. It is unclear if it affects the emission during testing. I think the cat converters do the heavy lifting when it comes to emission anyway.
I recently had my 78 smogged by the shop I bought the car from, RPM Motorsports on Sepulveda. Can connect if you if you want. I have all the smog equipment installed.
I would check timing on both banks 1st, if it's ok sync and adjust carbs. Idle screws sb 3 to 4 turns out Double check for vacuum leaks To pass Ca smog you need smog pump for high speed Cats Idle retard switch or pertronix ignition Should idle about 1k with AC off My 78 with 100k + miles has passed every time l had it tested. The cats are a must. No chance without. A little bit of poping back is common when cold but not when warm. Good luck Barry
Lots of threads on timing and carb adj. What did you do to the heads? Valves to tight would cause problems Barry
Barry - When I measured valve lash there were a few below spec and those were corrected. Everything was put back to factory except the Pertronix ignition was installed with Accel wires and Flamethrower coils. The car was running rough when my dad had torn it down 10 yrs ago - strong smell of fuel but don't know if it was popping like it is now. The smell of raw fuel is still fairly strong. The spark plugs on a few cylinders are wet and black with others looking nice dry amber. I just wonder if a few cylinders have some valve issues that need to get corrected. And it doesn't seem like a simple job to remove the heads. The intakes were enough of pain to remove with motor in car - can only imagine the challenge to pull the heads with 40 yrs of corrosion. The car is currently not registered which requires the smog cert. Would love to run a few tanks thru the motor to see if it improves and then decide if valve job is needed. Looking for advice if I should try to tune or if the popping could be indicator valve job is due.
Do compression and/or leak down test to see condition of the cylinder. If acceptable, tune the webbers to get it running and then see if it will run well enough. I don't think you will pass smog if the cats are not there,.
Duners I just listened to the video. Is that the only cylinder popping back? If so turn the idle screw out (counter clockwise) (rich) and see if that helps. The fact its popping back indicates a lean condition on that cylinder. If richening it with the idle screw doesn't help pull the idle jet and insure it's clean. You've got it on the fast idle cam. What does it do with the fast idle cam rotated or adjusted so it has no affect? The fast idle cam, if adjusted correctly, circumvents the idle stop screws on the carbs and makes it impossible to adjust or sync. Its also very difficult to get a good plug reading when it's cold on the idle cam. Looks like a piece of tape on one of the vacuum lines? I assume you've got the vacuum line coming from the base of the pass front carb, the one popping in the video, plugged or the vacuum lines are installed correctly. If not you would get a giant vacuum leak causing a lean condition on that cylinder. Barry
I did a leak down test and it ranges from 15 - 27%. Thr compression is 150-170 psi. Thr numbers don’t seem horrible. I do have cats but no smog pump or air injectors on exhaust manifolds.
thr popping is from multiple cylinders. The video is short due to upload size limit. The tape was left from trying to diagnose any vac leaks. It was attached the charcoal tank and no difference. When cold it takes a few tries to get it to run. Typically fires up and then dies. After a few tries and giving gas at startup it will idle with throttle cable adjuster turned out a bit. Even then it runs real rough and not responsive on the throttle. Popping out of multiple cylinders on front and rear bank. I did moving the cold start cam out of the way and didn’t have any impact.
These numbers dont look horrible. Tune the carbs up, balance them, and see how they run, The lack of airpump is not critical when the engine is hot.
Air pump is pretty important to satisfy good old CA! And, the pump has to be good. There is a Ferrari spec to be aware of. like 7~8psi when deadheaded spinning at (IIRC) 4000 rev's. Be aware of this. Many pumps out there are an awful waste of time. I suggest buying brand new. I could go on about 'how bad the pumps can be'. I'll just say the bad pumps can seize which can cause really big problems given it's driven by the exhaust cam, and to a much lesser degree, not provide enough pressure to get past the 1/2 psi cracking pressure of the A.I.S. check valves. Cats too are very important. Are your cats good? In case that wasn't enough fun, the motor must be in good shape and tune needs to be very good/excellent (B+ / A-). Carbs must be clean and synced well. As mentioned, popping when cold is not terrible. After it warms up, this should be pretty much non-existent. Sounds like could be lean or have crud in idle jets if constant. Ignition components are solid and distrib's need to be spot on as well, particularly in the rpm range for testing. Now for some good news: When the car passes SMOG, it'll run terrific.
There used to be an exemption for smog equipment that are no longer available. You have to fail for equipment missing, then go see a Referee, and go through some more level of madness to get the exemption.
The equipment you are "required" to have is Ferrari supplied. That means you are NOT required to buy a GM air pump to replace your NLA Ferrari air pump. You certainly cannot find anymore air injector rails from Ferrari or any of the several "approved" vendors for smog equipment in California (that is all they have jurisdiction over, in CA). If you cannot find it, you are exempted from it, at least that was the case 20 years ago.
Great info. I did talk to Eugenio and he doesn't have availability for service but did provide a wealth of info. He does agree that it seems the carbs just need to be adjusted and I need to get it on the road a bit. I have been using Birdmans syncing procedure and will see if further carb adjustments improve performance. Thanks for all the comments.
I made some serious progress and motor is running great. I turned out the idle mixture screws out 5 1/2 turns - still with 55 idle jet and 135 main - and popping significantly reduced. I drove around neighborhood and you could feel the hesitation in the transition around 3k rpm. I increased idle jet to 60 and set idle mixture screws 5 1/2 turns out. Ran around neighborhood and got to Op Temp - holding nicely at 195F. No popping and hesitation in transition gone. Great response off idle too. I took it down for a smog pre-test just to get a baseline. The one major offender was the CO at 7%. Seems like this needs to closer to 2%. I do have the cats but no smog pump or air injectors. I plan to re-test with 55 idle jet and idle mixture screws set to 4 turns out. Any less it won’t idle and stalls. Was thinking the following for a re-test: Get motor hotter - I had to wait about 15 min for the smog guy and imagine the cats cooled off a bit 55 idle jet with 4 turns out. Airbox lid off - ran this time with airbox buttoned up Do you think just carb changes will have significant reduction in CO? If I install smog pump- does it have any effect with mine having air injectors removed from exhaust manifold? Do I need to install air injectors to get CO within limit? Image Unavailable, Please Login
