# EFI yay or nay



## rheckman (Aug 28, 2018)

Anyone put efi system on 400 ram air engine?
Pros,cons,...
Thanks


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## bigD (Jul 21, 2016)

Their are some of us old school Pontiac guys who don't think these old Pontiacs should be strapped with late model technology. 

If they came with a Q-jet, I say run a Q-jet. They ran just fine when new. A correctly built & tuned Q-jet can run 9's in a Super Stock Pontiac, and a correctly built & tuned Q-jet can supply all the fuel you need for a street Pontiac, and get decent mileage, with the right combination of parts & tuning. 

If you want FI, sell your GTO & buy a later model car which came with FI, IMO. 

Opinions differ.

Some have the opinion "It's your money & your car, so build it like you want it".


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## PontiacJim (Dec 29, 2012)

rheckman said:


> Anyone put efi system on 400 ram air engine?
> Pros,cons,...
> Thanks


Better still, rather than ask us our opinions for the pros & cons of an EFI system, how about you fill us in with your list or reasons so we can compare?


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## rheckman (Aug 28, 2018)

Main reason for want is my Quadrajet is a bitch to tune in.

Main reason i don't want to,it should have and run what it came with.
But i have the Quadrajet that only has vac advance from trans switch so only in 3rd and fourth gear.
The alternative,run vac advance all the time,or replace quadrajet with one that has ported vac.
I have tried running both ways,changing timing as needed but I'm still not sure.
Of course they tell you the efi is bolt and go pretty much,but I'm sure there are issues a well
Bob


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## PontiacJim (Dec 29, 2012)

rheckman said:


> Main reason for want is my Quadrajet is a bitch to tune in.
> 
> Main reason i don't want to,it should have and run what it came with.
> But i have the Quadrajet that only has vac advance from trans switch so only in 3rd and fourth gear.
> ...



What year GTO again? Sounds like you have the set-up with the emissions controls maybe? Should be able to work around it I would think.


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## rheckman (Aug 28, 2018)

It's a 70 ram air 3,it has the Tcs solenoid and that's where vac line goes then back to dizzy vac.
Makes sense ,because otherwise it would be constant vac as there's nothing above the blades on carb for vac port.
I wish i wasn't dealing with this setup,although timing base is true because Tcs doesn't vac until trans kicks it when timing.
I'm around 16 tdc running slightly higher 800 rpm,seems smooth


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## PontiacJim (Dec 29, 2012)

rheckman said:


> It's a 70 ram air 3,it has the Tcs solenoid and that's where vac line goes then back to dizzy vac.
> Makes sense ,because otherwise it would be constant vac as there's nothing above the blades on carb for vac port.
> I wish i wasn't dealing with this setup,although timing base is true because Tcs doesn't vac until trans kicks it when timing.
> I'm around 16 tdc running slightly higher 800 rpm,seems smooth



This is going to cover 2 different subjects: The TCS System and your Timing (as I see it).


OK, I am looking at a schematic/diagram of the 1970 set-up you are talking about. I see that the vacuum source at the carb is below the throttle blades which will give you a constant supply of vacuum - just like as if you ran the vacuum line for your distributor directly to a manifold source like some do.

The TCS Solenoid is what open and closes the vacuum supply coming from the carb to the distributor. It is an electrically operated switch that opens and closes the vacuum and is controlled off of a switch on your transmission. When energized it it is closed and provides no vacuum to the distributor. When it is de-energized, it opens allowing vacuum through to advance the distributor. 

The switch on the transmission is a "pressure switch" that is closed in first and second gear and opens when in third gear (this must be for a 3-speed trans. It says there is also a "double terminal" switch and must be for the 4-speed so the switch is activated in 3rd & 4th gear.) So my understanding is that there is no vacuum going to the distributor while in 1st & 2nd gear. You only get vacuum to the distributor when in 3rd or 4th gear (or *D*rive if automatic).

Interestingly enough in 1972 the TCS Solenoid pressure switch that was on the transmission in 1970-71 was adapted to fit on the speedometer cable and was set to activate at 35 MPH, rather then in just 3rd or 4th gear on the transmission.

Personally, I don't see a problem with this as long as it is working as it should. However, I do see a problem assuming you are using a factory RA III distributor and its specs. Because you are not using the factory spec of 9 BTDC degrees initial at the crank at idle and you have your initial at 16 degrees (Ram Air IV was actually factory set at 15 degrees BTDC), the timing may become too advanced when the TCS operates in 3rd & 4th. 

16 degrees initial at idle may be fine and could be used, *BUT* then as the engine revs up, the mechanical advance begins to increase. RA III distrib. specs say that the centrifugal advance is 20-24 degrees at 4600 RPM's. So if you add the 16 degrees initial plus the 20-24 degree mechanical, you get 36-40 degrees total. My opinion - way too much! You are asking for trouble and will damage the engine. Total should be around 32-34 assuming you are using 100 plus octane if you have 10.75 compression.

You can run 16 degrees, but you have to now limit your total advance by limiting the mechanical advance in the distributor. You need to add a "stop" of some sort to limit the weights.

The RA III vacuum advance specs say you should have 20 degrees at 15-17 inches of vacuum. Again, if you take your total advance from above, 36-40 degrees and you add that to your vacuum advance of 20 degrees, you now have 56-60 degrees of total advance when you let off the gas with the engine above 4600 RPM's. This is engine damage territory. Total advance of initial, mechanical, and vacuum should not exceed about 52-54 degrees advance. You can get a different vacuum advance that only has 10-12 degrees of total advance and install it. This would solve this issue.

So I would keep the 16 degree initial if it runs best. Use a stop/limiter on my mechanical advance in the distributor to give me 32-34 degrees total. The swap out my vacuum advance canister with one known to have only 10 degrees total advance to give you the 52-54 total degrees of advance when you let off the gas. 

Now if this was me and I wanted to do a work around on the TCS system: 

Option#1 might be to find a 1972 speedometer activated switch to energize the TCS Solenoid. My guess is this may be pretty tough to find if at all.

Option #2 would be to use a "pressure switch" like a brake/stop light switch, and adapt it with a bracket that would be used on the carburetor much like the factory idle stop solenoid. You would want the switch to be open, 12Volts, when the carb is closed in the idle position. This would energize the TCS solenoid to provide vacuum to the distributor at idle and advance your timing. When you open the carb, the switch (12 volts) is shut off, the TCS Solenoid closes, and vacuum is disconnected from the distributor in the same way it would be when you open up the throttle blades. When you let off the gas pedal, the carb returns to its idle position and the switch is again energized causing the TCS switch to open and provide vacuum to the distributor again.

You will get vacuum to the distributor when you let off the gas and this is what advances the timing during deceleration to provide better gas mileage and engine cooling. 

Your options are that you can run the engine without a vacuum advance, use direct manifold vacuum via the carb port you presently have. Which ever way you go, you then have to bring in the correct initial timing at the balancer and then match the distributor timing curve to your initial timing. The way I see it now is that you have too much total advance and may do damage to the engine.

BTW, you don't even want to see what they did in 1973! TCS and EGR valves are tied in along with thermal and time delay vacuum switches.


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## rheckman (Aug 28, 2018)

Thanks Jim,

The 16 degrees is at 850 rpm.
i have tried around 12 degrees and lower rpm but it seems to bog,while trying to set idle mixture screws as well.

I am running petronix with flame thrower coil, per their website timing shouldn't change but I don't know.
Assuming the tcs is working correctly,its a 4 speed m21,I would like to be close as possible to timing specs.
Which is why efi looks attractive.
Im going to have to go out and try again,or maybe replace the carb.

Timing this car is easy and there is no jumping around from the timing chain.

Getting the carb in line is another.
I did replace pump piston,needle and seat as well as new gaskets as it was leaking at the pump on the carb,tested the vac is good and no more fuel leak.


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## geeteeohguy (Feb 2, 2008)

Nay. If your Quadrajet is a bitch to tune, you need it gone through by an expert, such as Cliff Ruggles. The Q-jet on my '67 has over 253,000 miles on it, has been overhauled twice by me in 36 years of use, and operates as seamlessly as fuel injection. Great mileage, fast start up, tons of power opened up. The engineers knew what they were doing. The Bubba Backyarders in the past 50 years of tinkering with a car? Probably not so much. From what I've seen in the past few years, the trend is "if I don't understand it, I'll just replace it". It ought to be "Since I don't understand it, I'm going to learn how it works". Just my 2 cents, probably worth less.....
BTW, I also run stock ignition points and coil. I prefer their reliability over Pertronix and aftermarket coils. There is absolutely no power or performance gain with electronic ignition. Only the luxury of avoiding points and condenser service every 15,000 miles.....which is an epic task.


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## PontiacJim (Dec 29, 2012)

rheckman said:


> Thanks Jim,
> 
> The 16 degrees is at 850 rpm.
> i have tried around 12 degrees and lower rpm but it seems to bog,while trying to set idle mixture screws as well.
> ...



How would EFI make your timing better?


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## rheckman (Aug 28, 2018)

It wouldn't,
But I have been going back and forth with tcs solenoid,or constant vacuum, etc.
I realize vac would be the same,its just the tinkering back and forth with this particular carb.
I uderstand how the carb is supposed to work ,I have to find the right spot thats all.


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## Lemans guy (Oct 14, 2014)

well you will get it and a great discussion by the gang. I run a Quick Fuel carb on my Pontiac 461 stroker.I have tuned in every circuit from jets idle and high speed bleed, Power Valve Channel Restrictors, Power Valve Primary and secondary jets. The Quick fuel has modern circuits to get right. Qjets are cool as well. Not a fan of EFI, work on that on my modern cars. Takes away from the car for me.

But on to the Dist. The guys are all correct. I curve these for guys on my Sun Distributor tester, but you can do it without that with a dial back timing light or timing tape on the balancer. First is to get your centrifigal advance nailed down. Because that determines where you set your base. So you disconnect vac advance and plug, take off one advance spring under dist cap so you won't have to rev the engine too high. then with your timing light see what your total advance is. rev it up to where it will not advance any more. That is total. Vac is never figured in Total. Now subtract what your base was set at, you said 16 BTDC.....what is left is your Centrifigal advance.

From the weights and spings and RPM only dependent. Now adjust your base to make the Total 36. So if the centrifigal was 24, then set your base at 12.......If it was 26 set your base at 10. Do not worry that you think it will not run good at idle with 10 Base.....That is where proper Vac advance does it's magic for you. 

you want a Vac can that pulls 10 Degrees advance, but guess what nobody makes one.

So you need get a Standard Motor Parts B26 can .....SMP VC 181.....O'Reilly Part # BWD V375. That can will pull 16 degrees advance, Too much advance. 

So email [email protected] get one of his "Vacumn Correctors"......I use them on all the original points dist that I curve.That will come with instructions and make that B26 Vac can pull 10 degrees of Vac. Then skip that vac hooked to trans,.....hook it directly to full manifold vac. That will give you with the examples above to 20 or 22 degrees idle timing and keep your total at 36.

Great power, cool idle no power loss at WOT ......will work great. You can also research and try to tailor your vac can to come in just blow your vac but the B26 will be close, it starts pulling timing at 5 to 7 Hg and is all pulled in at 11 to 13 Hg. Lars vac corrector will lower that a little and that should put it below your idle vac easy. you don't want centrifigal advance at idle.

no matter the carb your timing has to be right, knowing that factory setting was 16 is meaningless unless you know what is now centrifigal. it changes from wear and may have been too much even years ago. Adusting when the springs come in, a better curve, you can do last once you get the totals right.

PS I always take off the adjustable vac cans, got a pile under my Dist machine. Most just adjust the rate of vacumn and not the total vac. Some have stops, like crane but the best and ez est is what I said above, you get 10 degrees with max 46 for light throttle cruise. will run cool and strong and then dial in that Qjet or whatever!

Good luck on it!:nerd::nerd::nerd::nerd::nerd:


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## Lemans guy (Oct 14, 2014)

PS don't forget to put the advance spring back on the Distributor after you test for total advance!


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## rheckman (Aug 28, 2018)

Thanks,
Great info.
For the record i show ram air 3 timing at 15 tdc for 1970.?
Thanks,
Bob H


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## bigD (Jul 21, 2016)

rheckman said:


> Thanks,
> Great info.
> For the record i show ram air 3 timing at 15 tdc for 1970.?
> Thanks,
> Bob H



Your initial timing(at idle) is not near as important as your TOTAL timing, which is initial + mechanical. This is without vac advance. 

Some choose to not use a vac advance at all, especially on strip cars. You can adjust your initial by changing the position of the advance stop. Some new dist come with an adjustable stop. But if your dist don't have one, you can make one, several ways.

Let's say your engine runs best at 36° total, but that makes your initial(at idle) only 12°, when it idles much better at 16°. That would mean that your dist has 24° of mechanical advance(added when the advance weights swing out) So, if you set your initial at 16, that would make your total 40°, which on some engines might cause detonation. So, to have 16° initial & 36° total, you'll need a stop that will limit the mechanical advance to only 20°. 

Many Pontiac engines run best at 34-36°. But, I've read of some that like 32°, or even 30°. (A local dirt tracker told me that he ran his sbc dirt track engines at 40°, with the advance locked out.) Running it too low can cause overheating as well as loss of power. Some have to run it lower than where the engine would make the most power, because the engine has too much compression for the octane rating of the fuel they were using. 

As mentioned, if your dist does not have an adjustable advance stop, you can make your own. Some use a bushing, made for the purpose, some weld up a slot. On my HEI, I added a stop screw in one of the extra holes in the bar that the rotor attaches to. 

For high performance, most say you need to set your timing curve so that all your mechanical advance is in by no more than 3000 rpm. Some like it even a bit sooner. Some dist may not reach full mechanical advance til 4000 rpm or more. To make it come in sooner, you'll need to replace at least one of the stiff stock advance weight springs with a weaker spring. If that's not enuff, you may have to replace both stiff springs with weaker springs. 

Sets of springs are sold which usually have 3 pairs of different strength springs. Some say not to use the weakest springs in one of these sets, as they may not last very long. 

As mentioned, for street cruising, a properly adjusted & functioning vac advance has advantages. Another advantage is probably a bit better fuel mileage. 

Some(not all) recommend an adjustable vac advance. The Crane vac advance also comes with 3 pairs of advance weight springs. They make 'em for factory points type & HEI dist. 

https://www.summitracing.com/search...Horizontal&SortBy=Default&SortOrder=Ascending

Or, you can do it as described in the previous post. Apparently, guys have had success using different parts & methods.


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## rheckman (Aug 28, 2018)

Great thanks!


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## PontiacJim (Dec 29, 2012)

rheckman said:


> Thanks,
> Great info.
> For the record i show ram air 3 timing at 15 tdc for 1970.?
> Thanks,
> Bob H


No. 9 degrees. 15 TDC as I already pointed out was for ram air IV.


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## rheckman (Aug 28, 2018)

Ok,
thx


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## Lemans guy (Oct 14, 2014)

well said Big D and I agree, there are various ways to get your timing and curve correct. I have done some of the MSD distributors with the color coded bushings that make it ez to pick a centrifigal advance as well. The key is you have to limit Centrifigal, with custom weights from a curve kit, or a stop...a bushing, a weld, a screw....so you get too much.

In addition you have to limit your vac advance. Not the just rate but the total. Crane has the stop limiter there are homemade ways etc, but just an adjustable vac can, and using the allen key inside limits the rate. Those cans have a lot of advance in them. and you can play with them to keep the rate down enough so it never pulls too much.

Back to the 1970 Ram air. as Pontiac Jim says 9 degrees advance is factory. That car would have been running ported vacumn to the Dist with no vac advance at idle. This was for emissions purposes, a hotter idle causes hotter exhaust and burns off the pollutants. So it runs hotter at idle. Inside the distributor they made up for that lack of base timing by having more centrifigal, so you will see high 20's at least often more.

Now you have discovered that it idles better with more base timing,....(Think, idle timing).....it will. So how do you get there, well just like we have been all discussing. the Vac can that I see have way too much timing as do the dizzy's. all tolled 60 70 degrees.....and heavy dist springs.

if your centrifigal is say 27 leave it at 9 factory base.....and add 10 degrees of Vac timing at idle........from full manifold vac....now you will have 19 at idle, it will be smooth and cool.

test drive any pinging dial the base back 2 degrees and retest. Then work the spring. as far as all in on springs.

I shoot for 2800 to 3800 realistically, each car is different. I can often get 3200, or 3400,...on corvettes have got 2400, 2500 RPm...but that they were low from factory.

sometimes you get all but 2 degrees in by 3200, and 2 degrees will linger until 3600 or 3800. It will run great.

Once you get this right dial in the Carb.:nerd::nerd::nerd::nerd::nerd::nerd:

Let us know how you do!


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## PontiacJim (Dec 29, 2012)

*Lemans Guy*: "That car would have been running ported vacumn to the Dist with no vac advance at idle."

*PJ*: The lack of a ported vacuum hook-up on the 1970 RA III with the TCS system is the problem. The 1970 carb on that system uses a direct vacuum source as the fitting on the carb goes below the throttle blades. It has no other provision for a ported vacuum source.

So the OP has to treat the vacuum source to the distributor the same as having manifold vacuum _EXCEPT_ that the TCS Solenoid is closed and does not allow any vacuum signal to the distributor at any time other than 3rd/4th gear when it opens. This is one of the reasons the engine runs well at 16 degrees which it is now set at. 

I would eliminate the function of the TCS because it operates off of the switch that is controlled by the 3rd/4th gear selection which electrically opens the TCS Solenoid to allow the direct vacuum sourced from under the throttle blades of the carb to go to the distributor's vacuum advance can- so the engine's vacuum signal to the vacuum advance is only allowed in the 3rd/4th gear range. In my opinion, and looking at the factory specs for his car with RA III, the initial+mechanical+ vacuum advance = way too much when letting off the gas or part throttle cruise in 3rd or 4th gear only with the timing set at 16 degrees. Also too much advance with initial + mechanical in my opinion in any of the gears.

So again, the work around is to ditch the TCS function and treat it as if the vacuum to the distributor is hooked to a manifold source and adjust the mechanical + vacuum advance accordingly to match his preferred 16 degrees of initial. Or, pull the timing back to 9 degrees like factory and keep the TCS function. Could also ditch the TCS function, keep the initial, adjust mechanical to provide a total that the engine can live with and not use the vacuum advance can at all. OP never described why 9 degrees won't work or what the symptoms are that he does not like.

I would also look into the timing curve to see when total is coming in.

So this is a little different than we normally see here because of the TCS system and the 1970 only carb having direct ported vacuum. The beginning of Emissions crap to stifle the engine. :thumbsup:


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## rheckman (Aug 28, 2018)

Thoughts on running at constant manifold vacuum?
Would base timing still be set with vacuum plugged.
Because now idle has vacuum all the time.
This set up is weird.
Could add ported libe to carb,or replace with one that does,because i don't know how i would test
Tcs at bench.


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## rheckman (Aug 28, 2018)

Sorry meant ported inlet..
I bought this car just last August and vacuum advance not connected to dizz or Tcs,starting to see why.


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## Lemans guy (Oct 14, 2014)

Bob, Yes you always set base timing with Vac to the distributor removed and plugged. Base timing is just what you set from your hand it is fixed and never changes unless you physically change it.

Now think this way,....with no vac advance Base timing and idle timing are the same..........That is how they ran cars for better emissions, with ported Vac that did not come in at idle. As Pontiac Jim pointed out (Great Find PJ) this car had the Vac advance hooked to the TCS line and did not operate at idle, only until 3rd gear.

In effect it operated similar too or worse than ported as it came on with timing later. With Vac to full manifold Vacumn your idle timing is your Base + the vac advance. so like I had discussed earlier and so did Big D and PJ,..if your Base was 10....with 10 degrees more from vac....your Idle timing would be 20 degrees.

But Alas, we are addressing the problem in the middle.... as the first thing that you need to determine is what is the centrifigal advance from the weights and springs inside the distributor. Once that is known you work forward, without that known your base timing setting is just a roll of the dice. I described how to do that in the car.

Google this article,......"How to Optimize the Centrifigal Advance in Pontiacs", .........that will show you how to do it with the distributor and a protractor.

Your base timing, with vacumn disconnected and plugged should be set at........................36 - your centrifigal advance...........so if you have 20 centrifigal.....36 - 20 = 16.

You have to start there and then if it is not too out of whack you can set base and add vacumn advance.

Your car you said bob was not hooked up for any distributor vacumn advance, not to the TCS line and there is no ported line and it was not hooked to full Vacumn.

In my recommendation Full manifold Vac to the dist when done right as described will have a cool smooth idle, a strong light pedal acceleration all throughout the RPM bands and hurt no WOT, and give an almost perfect Air Fuel Ratio also, at idle and throughout.

Some may recommend ported vac, you can try it both ways. Stay with it, you have to get it right before any carb stuff can be right as well. Many carb problems are really timing problems.:nerd::nerd::nerd::nerd::nerd::nerd::nerd::nerd:


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## rheckman (Aug 28, 2018)

Thanks ,

Like i said before i don't like the setup.
I also would like to think i can set up as stock,with Tcs for now and see how it goes.
Problem is testing the switches.i can test for juice at the Tcs,but the trans switch im not sure as it's run by shifting ,
Unless just putting it in gear,clutch still in i can see.
Reg's,
Bob H


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## PontiacJim (Dec 29, 2012)

rheckman said:


> Thanks ,
> 
> Like i said before i don't like the setup.
> I also would like to think i can set up as stock,with Tcs for now and see how it goes.
> ...



I think you may be over your head on all this. I suggest you take it to a shop in your area that can sort it out for you. The system is pretty straight forward and should be very easy to diagnose and set-up, either with the TCS or if you delete it. :thumbsup:


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## rheckman (Aug 28, 2018)

ok,time to move on then. thanks


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