Questions from a newbie on EFI install on 1987 Firebird
Hello everyone. Let me introduce myself. I am a commercial pilot that has a passion for classic cars. I have a 1987 Firebird with the carbed 305 engine. The car has 13,000 original miles on it.
I am unhappy with the carb setup. I am in the due diligence stage of researching the FiTech go street unit. I have a few questions that techs at FI cannot answer.
Since its a carb engine, there is only one fuel line coming from the tank. I absolutely will not drop the tank to make a return line. Too much of a hassle. I have removed all the emissions equipment and have left over a fuel vapor line to the tank that was connected to the now removed charcoal canister.
I plan on using that line for a return line. The carb that is on the engine is a computer controlled Rochester. The computer controls the fuel, timing and ignition. Replacing the carb will delete all the functions of the computer.
I don't plan on installing a new distributor for ecu timing until I get the unit to work properly. My question is how can I control timing advance and retard without the computer??
I would appreciate any suggestions that you can give me.
Many thanks,
Louis
Welcome. I'm curious about something, how is the computer controlling the timing now without an ecu timing distributor? I guess if you knew how that was done, you could build a converter to take the fitech timing outputs and change it to what your current distributor needs? Good luck with that one. 😀
Welcome Louis,
I am the created of this site and you have asked some questions that are part of my direct experience. I am a 3rd gen Camaro/Firebird fan. Have had many of them. My current 3rd gen is a 1989 Iroc with a 305 using a 600na Fitech unit. Although not stock, it is a very good example for your car.
Because your questions are application specific, information and support from Fitech will not be received. Don't let that upset you. They are great guys. Offering application specific advice would be very expensive and increase the risk of liability for the company. This is where we, this website, come in.
There a couple of ways how you could accomplish your Fitech install. I will hit on the main pieces then give you the separate options at the end.
1. First, your car does have a return line. It is not at the carb though. It is at the fuel pump. You will find 3 ports on your mechanical pump. Feed, supply and return. Your feed is the larger 3/8 line and the return is the 5/16 line.
My recommendation for your fuel system is an in-tank pump. I am not a fan of inline pumps or fuel command centers. These products will work. I believe if the OEM put the pumps in the tank then it must be the most reliable way. If you decide to go with my recommendation, we can go over the pieces and process to accomplish an in-tank pump for your car.
2. If you have not purchased a unit yet, I would recommend the 600na Go EFI 4 system, #30002. The 400 units are lacking in features such as timing control and fan control. Both will work on your application. I prefer having the added features.
3. Ignition- This is where things split. All the units can run "without" timing control, so option 1 will work with any unit. Option 2 will only be for timing control units, such as the one I recommended above.
Option 1- Without timing control. You will need to purchase another distributor that has mechanical advance feature. $100-$200, depends on brand and quality. Then there will be a one wire connection from the distributor and the Fitech. This is the blue wire and must be shielded for proper function. There is a shielding sticky in the electrical section.
Option 2- With timing control. In this case you can use your current computer controlled distributor or upgrade to another non-advance distributor. This is also a simple wiring install. A little more involved than option 1, but not hard.
I hope this gets you started. There is a lot more I could add, but need to know your direction. Keep us updated and good luck.
Quote from bdhulderman on December 8, 2018, 12:05 pmWelcome. I'm curious about something, how is the computer controlling the timing now without an ecu timing distributor? I guess if you knew how that was done, you could build a converter to take the fitech timing outputs and change it to what your current distributor needs? Good luck with that one.
Hi, thanks for the reply. I am not that familiar with how the distributor works with the ECU.
There is one wire coming from the ECU that goes to the distributor. To do timing, this wire has to be disconnected.
More research has to be done. Good thing this is a spring project.
Louis
Quote from Austin DeHaas on December 8, 2018, 1:13 pmWelcome Louis,
I am the created of this site and you have asked some questions that are part of my direct experience. I am a 3rd gen Camaro/Firebird fan. Have had many of them. My current 3rd gen is a 1989 Iroc with a 305 using a 600na Fitech unit. Although not stock, it is a very good example for your car.
Hi Austin, thanks for the prompt detailed reply. This is lacking on a lot of forums. I did look at the 600 and I agree that is the one to go with. I picked the 400 because my HP falls in its range. I am about 30 HP short for the 600, should this be ok?
And you are right about the mechanical pump, it does indeed have a return. I should have remembered , I replaced the pump this past spring.
This solves my return problem.
I agree that an in tank pump would be the best. However dropping the tank is my last resort. I could not do it myself and would cost about $700 to have a garage do it. In the tank now is a low pressure pump that pressurizes the line for the mechanical pump to prevent vapor lock. I will do the in-line pump and if that does not work out, then Ihave no choice but to drop the tank.
I did also find a nice 2 wire distributor made by MSD where the advance is already locked in.
Attached is an engine shot showing the Rochester carb that is in use now.
Louis
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Clean car.
Great news. Your current distributor is very easy to modify for the Fitech. In fact this is the style I use. Usually referred as the TBI distributor or small cap HEI.
I understand your apprehension to dropping the tank. Fitech has upgraded their line of pumps. Much more dependable. Might give them a look. I would keep power to the lift pump to assist the prime to the inline pump.
The 600 has the pressure regulated at 58psi. The 400 is 43psi. Same injectors as far as I know. If the unit has trouble tuning to the low HP, I would swap the regulators. A small inconvenience to have the extra options. I will confirm the injector sizing if you decide to go this route.
Quote from Austin DeHaas on December 8, 2018, 9:15 pmClean car.
Great news. Your current distributor is very easy to modify for the Fitech. In fact this is the style I use. Usually referred as the TBI distributor or small cap HEI.
Hi Austin, can you tell me what you did to modify the stock distributor? Its a simple dist with only a module inside.
Does this forum have the option to do private messages?
Louis
No private message option.
When you take the cap, rotor and module out, you will be left with a magnetic pickup with a 2 wire harness. Snip the harness end off and attach an MSD mag pickup harness. Must look for the part number. I then cut a piece of plastic to fill the hole on the cap left from the module. Leave a small relief for the harness to pass through. Then simply plug into the 2 wire harness from the Fitech. Very simple and cheap. I have done many like this.
MSD 8860 harness
Hi Austin,
This will be cost saving for sure. Thanks again for your input. I want to donate to your site, I think its great. However I do not like cc on the net. Have you thought of a PayPal method of donations?
Louis
It is PayPal, just not a PayPal button. Thank you for your support. Keep us updated....