willy_g77

hello i have recently bought a 1979 rx7 with 72,500 original miles. but it has some issues. i was just going to sale it, but have decided to keep it. well here goes.... it has a leak in the carb which looks like it is coming from the accelerator pump. but 3 weeks ago it started kinda hard, but ran and drove great after warming up. but today i went out for a little drive and the battery was dead, so i took it out and gave it a charge. put it back in and it started, the tach said it went up to 7,000 rpms.. but there was no way it was that high, and the GEN, add engine oil, and check coolant lights were all on. and it wouldnt stay running unless i held alot of peddle and held choke, but when it warmed up and it was idling fine, then it was saying it was idling at 5,500 rpms, which again it wasnt. but i couldnt get any revs out of it. no matter how slow i hit the peddle it would die if i gave it any gas. i got out and looked and i saw a light smoke coming from the alternator, so im guessing thats a possiblilty? and i havent put a belt back on the air pump yet, and i noticed that the pulley for it was locked up? so can any one give some advice. i also want to rebuild the carb, but i was told that some rebuild kits are better than others, where can i get a good one? and how hard is it to rebuild one? sorry for being so long, but any7 advice would be greatly welcomed.

BlackWorksInc

****, that's a serious load of problems... Well your air pump clutch sounds locked up, (the one for the A/C right?) As for your crazy Rev readings, I think the cable to your Tach is seriously fucked, or the connection to the engine is. Your carb definetly needs rebuilding, My recomendation would be, hit a Pick-N-Pull and just get another one to swap it out along with any other parts that are FUBAR. It will probably be cheaper.

willy_g77

no not the ac compressor, the air pump for emissions. the "smog pump".. other than the carb needing rebuild the other problem seems to be the same thing... im woundering if a bad alternator would kick on other lights?/ make other wierd electrical problems?

Anarx

your air pump is locked up? try this disconnect the pipe that goes to the cat from the air pump and see if you can turn the air pump by hand.

if you can then your cat is more then likely clogged up as well.

if you feel comfortable enough to rebuild your carb the kit is around $50 from mazdatrix. but swapping a carb from one of the pull it yourself junkyards will be cheaper.

I take it that it does have oil and coolant so i would start checking wiring sounds like a plug got removed or a ground wire broke. go download the factory wiring diagram and trace the wire's for those sensors.

i'm sure guys on here will have some better ideas on whats going on but that is where i would start.

hanman

Sounds like your altenator has headed south. I would pull it and take it to a local auto parts store, they can test it for you for free.
Second, you need the belt on the air pump, or the altenator won't work right. Either eliminate the air pump and put a yoo hoo belt on the alt. or put a double sheave pulley on the alt. and a set of "matched" belts, or fix the pump and use a new belt.
On the carb. You will always have to use the choke when the engine is cold to get it to run right. That's normal. See if fixing the alt. fixes the tach issues.
The tach runs off the leading ignitor (and before someone jumps in here and says that't not true, that they run off the trailing ignitor, this is a 79, not an S2 or S3)
So, anyway, maybe check the connection at the coil and see if there is a problem there.

hanman

BTW, if the carb is leaking on the engine, you better fix that before anything else. Otherwise everything is going to go up in smoke.

willy_g77

its electrical... it was doing the same thing today... i fought it and kept it running until it would idle.. then all of the sudden tach started working. and the warning lights went out.. then i tried to see if it would let me rev it.. and it did... but when i rev'd it i heard a clicking , it sounded just like a relay clicking, then i let it idle, then boom the tach sooting up to 5,500rpms again and lights come back on.. so what relays would cause this? i didnt see a voltage regulater on the back of the alternator.. is it built in? or where is it? i think it may be my problem...

hanman

On the 79 the voltage regulator is seperate. On all other RX's it is integral to the alt.
BTW, I was partially wrong about the tach and leading ignitor. IF your car is stock you would still have points. Correct?
I think most of your electrical problems are alt/regulator related.

trochoid

iTrader: (6)

On the 79s, when starting, the tach reads as a voltage gauge. Once the engine is running, it's a tach again. It's an odd setup. The alt is externally regulated. The regulator is the ceramic looking part on the forward side of the driver's strut tower.

Sounds like you have 3 main problems to address. The alt needs rebuilt. If you're comfortable with minor wiring, install an S4 alternator. The carb needs rebuilt. Do not let the AP leak go, engine fires have destroyed a number of rotarys, particularly the FI ones. I buy my carb kits through AutoZone, it has the good parts. If the airpump has siezed, then most likely the exhaust system is plugged up. The thermal reactor style exhaust system is NLA. You will need to replace it with an FB style exhaust or one of the aftermarket header systems w/o a cat. This is likely the cause of the engine not reving.

Next thing is the dizzy. It's a points style unit and needs frequent attention. It can be replaced with an FB electronic dizzy too.

Eveything you need for the above work you will find 'How Tos' in either the FAQs, the archives or in the FSM and carb manual. Check my sig line for links.

Welcome to the forum.


DemonSpawn67, more reading and less posting might allow you to give more constuctive posts in the future.
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hanman

Trochoid is an old fart like myself.

try this link, it can't be beat for first gens:
www.mazspeed.com