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Hey everyone, this is my first time posting here and also a new owner of a FB Rx7. Im having a problem where the car starts, but it dies when I try to idle it. I replaced the fuel pump and distributor on it recently and its finally starting up again but just wont idle. Also upon starting it up the exhaust shot out a huge amount of white smoke, not sure if its a seal breaking in the housing, or its just from not starting for a while. If anyone has any ideas or resources as to where I can learn more about this, please let me know, thank you!
Welcome,post some pics of your car. Have you drained contents of gas tank and put in fresh fuel? What's in there is likely degraded and not conducive to keeping an engine running. Have you inspected/changed fuel filter? There are sight glasses on both float bowls on carburetor and fuel level should be exactly 1/2 way up on sight glass. You will need to remove air cleaner to see them and may need a mirror to see rear one.
Take the time to set base ignition timing,may be a factor in engine not wanting to idle. If stalling persists,try adjusting idle mixture screw. Turn in til it seats lightly and turn out @4 turns,this will be a slightly rich mixture but will help it idle initially. Idle rpm should be @800.
Often,from sitting with old fuel,the idle circuit plugs up in carburetor.It is the smallest circuit with some tiny orifices and is the first part of carb to have problems after sitting dormant. Some have some success running seafoam in tank to attempt to clear jets in carb. It will do no harm and may well help. If you find none of the above helps,you may have to remove and disassemble and clean carb. There are rebuild kits available,don't use replacement needles/seats provided in kit as they're poorly machined and can lead too flooding. Try not to alter float settings,they're usually spot on from factory. If you can get carb off,cleaned and back together,you can usually have a running car that with correct ignition timing and idle mixture/speed adjusted will be a good running car.
Also a good idea to replace cap/rotor/plugs/wires/air and fuel filters. Maintenance items that are relatively inexpensive and if not sure of age/condition should be replaced. Once running well and warmed up,change oil and filter and top up/change coolant.
So here is the list of things i have done to the car so far.
I have had the gas tank cleaned out as well as replacing the fuel pump and filter. Im thinking I eventually have to throw on a regulator for the fuel pump since it is aftermarket.
When I put the new distributor in, I did notice that the timing pin, not sure if that's the correct name, wasn't exactly lined up on the yellow maker on the pulley itself on the end of the engine. Not sure if this is a factor or not.
For the carb, I had someone look over it recently, they had told me that there was a shutter valve jammed closed or open in it. I do know that for sure with the new fuel pump it is getting a healthy amount of fuel sent, if anything, it might be a bit much and will have to find a regulator to throw on it. So youre suggestion with cleaning and rebuilding the carb is probably the move.
As far as the idle mixture screw, I havent found it and tried adjusting it yet, so ill definitely give that a shot in abit here.
Ill send some more pictures of the car itself in a little bit here!
Couple questions...
what kind of fuel pump did you install. Nikki carb very particular about fuel pressure. It likes 2-2.5 psi and no more.
Can you clarify your distributor install and why you replaced it?
Shutter valve diaphragm failure is a common problem. With air cleaner lid off,do you hear a sucking sound from bottom of air cleaner?
Try blocking the holes in bottom of air cleaner with your hand and see if it will idle then.
Google foxed.ca RX7 manuals for access to factory shop manual for your year car and search in fuel/emissions section for shutter valve testing/replacement.
Oh really? I think i found my correct fuel pump online, going to find the box that it came with and check, but im certain that its about 5-8 psi pushing out of it...
I installed the distributor due to no spark coming from it, the one that was in there wasnt turning over the engine and the new one i got finally got it start up again.
Havent tried that yet, due to trying to turn it over so many times lately, I had to let the battery charge back up but i will give that a shot too!
I'm checking the foxed.ca manuals right now and im gonna search around for the shutter valve section.
When I put the new distributor in, I did notice that the timing pin, not sure if that's the correct name, wasn't exactly lined up on the yellow maker on the pulley itself on the end of the engine. Not sure if this is a factor or not.
Don't confuse the distributor gear role pin with the timing mark.
When you say you replaced the distributor, do you mean the whole Distributor??
The cap and rotor are wear parts but the actual distributor (metal parts pictured) should last 100's of thousands of miles.
As GSL-SE said the original Nikki carb likes 2-2.5 psi fuel pressure. If you installed an aftermarket Mallory/Holley/ Edelbeock/etc pump making 5-8 psi that is way too much pressure and will flood the carb. You will need a regulator to turn it down to 2-2.5 psi.
if your not getting spark (and how did you determine this???) It is not the mechanical distributors fault. It is something electrical in the system.... Coils, ignitor, plug wires, something. I'm not a pro mechanic but saying "my car won't start, so I'll change the distributor" is like saying "my car has no brakes so I'll change the tires".
06-13-20, 09:54 PM
