satanicmechanic

Hello, new member here. I have a 86 GXL with various go-fast mods and have been working on them a number of years (Gone through three already). Recently my friend purchased a 84 GSL-SE and we've been restoring it back to good health. Right now we're focusing on the engine as it is not putting out anywhere near as much as mine (the 86). I'm not trying to sound like my car has crazy power, but since the FB weighs a bit less than my car and the 13b it came with has 10-15 hp less (factory) we should be running with a similar amount of "oomph", which it is not.



So far, we have replaced the distributor cap, plugs, motor oil, tranny oil, diff oil, battery, and main cat (as they were all gutted when he got it. Aux ports work fine now). We're planning on new fuel filters (in-line and tank) and air filter. Also in the works is a compression test after I read up on it a bit.



Basically, what i'm asking is what else should we be looking for? I'm sure the compression test will tell us if the motor is toast. The motor itself looks like it's been taken out and painted before, which i'm hoping it was also rebuilt, but I have no idea.



Any insight would be grand. Thank you.



P.s. I actually joined a long time ago. I just never post anything.

RX-7Doctor

Depends on your performance comparison and if you have ever driven a properly running SE. What does the Fc have for mods?

If you have a header system and a lightened steel flywheel on your Fc, then yes, the Se will seem slow if it is in stock form.



#1 to check on the Se is fire to the leading plugs.

#2 Compression

#3 Front cats, are they clogged? Or is the exhaust system plugged past the main cat?



Doe the engine idle poorly or have an abnormal sound to it?



Remove the fuseable links for the injection system and replace with either known good links or take the 2nd gen fuses out of the FC and put in there and see if there is a difference.

satanicmechanic

I checked the coils the other day and the leading and trailing wires to the distributor were reversed. I put them back the right way and reset the timing, but it was still firing a bit erratic, as in say 5 right on, 1 behind, 3 right on, 2 advanced. Compression test will probably be done this weekend. The pre-cats were gutted, as was the main cat. My advice was to put a new one on with the bung running up to operate the ports.



My car isn't really stock ( rebuilt motor with 4k miles, straight pipe, ported intake manifolds, throttle body mod, cone filter, no emissions, no aux ports, etc), but I did have a completely stock FC for a long time and it had more get-up-and-go than this car. I'm just guessing it's time for a rebuild on the FB's motor, but i'm going to do everything I can before I let the car give up the ghost.

j9fd3s

if they are still there, make sure all the throttle plates open. there are 2 that are supposed to be closed when the car is cold, but the chingaso fails, and they stay closed = slooooow



also check the timing, if its been apart, maybe they got it wrong.

BeaterRX7

If the timing's erratic, check for vacuum leaks. Make sure the distributor is bolted down (it's a no-brainer, but double check it). Are both the leading and trailing plugs firing? Not just making the timing light flash, but firing with a healthy spark? Check the spark plug wires at night to see if they're leaking.

satanicmechanic

That's what I was thinking as well. There isn't that much play in the gas pedal which leads me to think the cable needs to be adjusted so the butterflies open fully. I'm not fully sure the timing marks are in the right place. The pulley on the end of the crankshaft is painted to match the exterior of the car so I'm not fully sure they made arrangements to put the timing marks back in the right place. I know there's some sort of way to re-find the marks and will look into it.

satanicmechanic

The distributor is bolted down pretty good, but i'll make sure to double check it. I'm not 100% sure it's firing on all 4 plugs but will check this week and report back. I'm sure there is probably a vacuum leak.

j9fd3s

no actually theres a little chingaso that closes the 2 secondary throttles when the car's cold. when it fails, and they do, the throttles never open.



cable should actually be a little loose

satanicmechanic

Is it the mechanical choke or the thermowax? We checked yesterday and all the butterflies open.

We're going to do the compression test this weekend.

j9fd3s

the mechanical choke. thermowax just bumps the throttle open a little