Root79Rx7

Situation: 79 RX blew the motor, i bought an 82 Parts car with no carb but was told the motor ran. I did the motor swap with my machanic, the 82 12a motor now has a rebuilt 79 carb from Pinnapple racing or RX7Carl. The car has run since we have done the swap, so i know the motor is not blown. It has been driven since the swap but is not the greatest. There is no rats nest.

Problem:

1. I cannot get it to idle. I have not messed witht he idle **** yet either, is this the problem. we can get it to 850, but is very jumpy, with a new carberator could it just need to idle higher it idles best at 1200 rpm with foot on the pedal.

2. Car has a very tough time starting. One week it would start right up, the next week i go and get ready to take the car home i get 1/4 mile down the road stalls and could not get running till another 30 minutes, the car never made the 15 mile trip home, but had to be pulled back to my machanics house. It possilble flooded from not being able to start it.

3. While on a cruise, the car will not open pass 4,000. tried runnning up to 5 and the tach just jump eratically, the motor is not reving higher but the tach is eratic. Could this be secondaries not opening or electrical.

My machanic is stumped and tired of the car being at his house for about 1 year now. The major question is what is the problem. I have checked for vaccuum leaks, we have changed the fuel filter, we have new gas in it. Is this an electrical problem, Fuel pump problem, or just neads an idle adjustment.

I have tried to explain the problems, i will answer more if need to be but please help me get this running, Root4three is my aim, it may be easier to explain that way also

Sterling

At 1200 rpm you're no longer running on the idle circuit.
There are several posts just by myself on how to tune the.idle. Check the FAQ thread, too.
If you pull a plug and it's wet, ou've flooded it. Could be a few reasons for this,but I wouldn't let it worry you unless that's still a problem after you have the carb tuned.
The tach going nutz is a direct tell-tale of a bad trailing ignitor. However, you shoudn't have such terrible performance with you trailing plugs not firing. I think your ignition system is messed up.
Do some research on the ignition here on this forum. Start there. Crank the idle screw till it runs at 1000 or 1200 so it doesn't keep stalling. That eliminates the carb as a problem in the equasion. Fix the ignition, get a new trailing ignitor off a donor car (Get both trailing and leading, and don't bother buyiong new ones, cause they're expensive as hell). Replace your fuel filter. Replace your cap and rotor, if you have not done so already. Ceck all plug wires, and if you have thebucks, get new ones. If you'r poor, at least make sure the contacts are clean and secure on the plugwires, and also other ignition wires. Crack the hood at night with engine running and look for arcing. Spark jump can cause an inconsistant gremlin to play games with your head.
When you've finally got the ignition ironed out, then return attention to properly tuning the carb idle.
When all is taken care of (and not before!) do the MMO treatment. (Search.)

Root79Rx7

Would it be beter to upgrade to a direct fire system, or i have heard about putting a 2nd gen system in, would those be beter if mine is shot?

Sterling

Actually, the way I see it is if you can't get your stock ignition working right in the first place, then you have no business trying to modify it!
Perhaps someone else can better help you. I'm just a carb guy.

Jeff20B

iTrader: (13)

Sterling's reasoning is sound. And that's coming from an ignition guy.

Root, how old are your plug wires? There's a chance if they're leaking voltage, it's messing up the tach signal. If they're old, change 'em.

Root79Rx7

plugs and wires are brand new through mazdatrix, less then 1 year old with about 15 miles on them. im going to the car later today and check ignition. ill report back tonight, thanks for the help

Rx7carl

Definately recheck the ignition system. Check that all plugs are firing, that the timing is correct and check condition of the plugs, cap, rotor, wires. It wasnt an SA carb Matt, it was an FB carb. Take Sterling and Jeff's advice.

Not passing 4k makes me suspect ignition. Even without the secs you should get past that just a bit slower. Sounds like something is breaking down there. A dead fuel pump will usually just quit intermittently and the car will just die, but run great when the pump is working. HTH and keep us posted.

Root79Rx7

called and check a could of junk yards today, i found 2 one with no engine the other with no igniters, odd i think. Anyways, if anybody has a set of igniters please pm me. Should i also change the coils on the drivers side door?