I'm switching from tbi to carb, and I was wondering if I have to keep the egr valve.Can I just buy a non egr intake manifold?

 

EGR is an emissions-control system. Since you're destroying the factory emissions control capabilities by installing a carb, you don't "need" the EGR valve.

 

also do I need to wire the alt differently, and will all of my gauges still work.Mainly the speedometer

 

The distributor will either be wired the same, or need slight modifications if you go with a coil-in-cap HEI. If you have an electric choke on the carb, you'll need to provide switched 12 volts to it (it's not a good idea to use the distributor power wire for that). Otherwise, everything will remain wired the same as before, and all gages and speedo will work as before.

 

Do you know of the modifications that I would need to do with the coil-in-cap style hei distributor? That Is the kind that I have, also what about the coolant temp sensor and the opsu, will they still work properly?

 

You need to take the power and tach wires from the original coil and route them to the distributor cap of the HEI. I'm not totally familiar with the small-cap distributors (my system is from an '86, the last year of the large-cap distributor used by the factory), but I believe the power wire is pink, and the tach wire is white. You should be able to search for the correct answer (I don't even know if they're marked on the stock remote coil), or someone who knows could respond.

The coolant temp sensor technically is the weather-pack connector on the intake manifold. It doesn't have anything to do with the temp gage in the instrument cluster. The sender for that is in the head.

I don't know what the "opsu" is.

 

opsu (Oil Pressure Sending Unit). Isn't there a temp sender on the side of the block? Thanks for the info so far, it's great learning while you go along.Is there any way for me to make a regular holley fuel regulator a bypass style regulator, or return the fuel with a tee before the regulator? I'm trying to keep it as inexpensive as possible because my funds are running on empty.

 

Oil pressure sending unit - gotcha. Same thing, leave it where it is, it'll work fine.

There is a temp sending unit in the driver's side head. There is a radiator fan switch in the passenger side head. There is a knock sensor in the block drain hole on the passenger side in front of the starter.

I've seen a guy use a needle valve on a return line to let fuel return to the tank and use a standard reg to the carb. It'll take a little trial & error to find the right amount of fuel to send back while maintaining sufficient pressure to feed the carb. A return style is certainly simpler and more fool-proof.

You will probably have to provide another power source for the in-tank fuel pump. I believe the signal is provided via the ECM in the stock configuration. Again, not sure about that, no direct experience. Be sure to maintain the oil pressure switch function if you do rewire the pump.

 

Ok great, I can't wait to get this job done so I can get the car back on the road and stronger than ever.

 

What if my vats system doesn't work properly? How would I be able to get the fuel pump to run?

 

I haven't heard of VATS being affected by an EFI to carb swap. But, if you have issues, there are a couple of tech articles linked from the thirdgen.org homepage such as this one https://www.thirdgen.org/vats_passkey_system .

 

Just picked up an '89 2.8 and can't seem to find the proper part to replace the mechnical temp sender/gauge (thick copper wire with spring covering) I found on the left side of the motor. The sender should connect to a single spade with a dark green wire but all the online and local shops think the part is the one with two wires on the thermostat neck.

Sure could use some help here as a newcomer.

Crock

 

Ok here is another problem I just ran into, I being the genius that I am left the keys in the ignition in the on position. I put a screwdriver down under the hood and it somehow touched wires on the fuel pump relay and it popped , now the pump doesn't even prime. I also noticed that the ses light doesnt work anymore, it was just working before I put that screwdriver down and that pop happened. I even changed the relay and that didn't help.What wires coming from the fuel pump do I have to use to try the pump on a switch?

 

Nevermind, I figured it out. The fuse blew in the little fuseable link next to the battery.

 

Finally got this **** running, but now I need to set the timing. when I was TBI I was running 9* advanced so what would be appropriate to run with the carb setup?

 

A good place to start is 12 degrees BTDC with the vacuum advance disconnected and plugged. The "proper" way to set it is total mechanical, which is typically 36 degrees BTDC, again with the vacuum advance disconnected and plugged but with the engine rev'd up to where the maximum mechanical advance is observed. But, that requires an advance-type timing light, or timing tape on the damper, or a graduated damper.

 

OK great, here's another question. as stupid as this may be I have to ask,would the EST wire have anything to do with timing anymore? It's still connected and I was wondering if it would give me any kind of trouble

 

It won't affect anything either in a good way or bad.

 

Sweet.would Having low fuel pressure on top end, or say when the secondaries start to open be the cause of a slight humming noise that I hear? I Think that it's coming from the valve covers, like I said on top end or in higher rpm is when I notice this noise. Just cruising its fine, but when I get on it I hear it. The timing is set at 6* advanced now, but when I had the tbi setup I was running 9* and it was fine. Im going to check my spark plugs and get a dash mounted fuel pressure gauge to see what's really going on.

 

It'll probably like 12 degrees initial better.

Gotta keep the fuel pressure up.

 

You're probably just hearing the carb sucking air when the secondaries open up. I have to question this...why did you do the swap in the first place?

 

Yeah that could be it, or it could be that my smog pump is still attached and sputtering air out. As far as the swap goes I did it due to my vats module taking a crap, and a number of other things, I was also able to get my hands on an intake carb and dizzy for dirt. I don't think that I would have had the time and patients to try to learn DIY tuning. The next step is actually to get the same comp cam that you are running, and a 10" stall converter.