jj79hippy211

has a fuel cut or missfire from 3500rpm up to 4000 and wont go any further gotta stay out of the throttle when up to the 35 point to go up. timing, fuel cut? where should i start

Aaron Cake

iTrader: (1)

Test the leading and trailing ignitors.

JMoneyLSB

Does it seem like a similar problem to........

https://www.rx7club.com/new-member-rx-7-technical-256/bogging-wot-999550/

I know that urs is EFI but could be a similar issue

RK53

Did you check your fuel pressure? Fuel flow? Fuel cut isn't anywhere near there. Also ignition problems can act like a starving for fuel issue. Weak spark, bad plugs etc. Verify it all.

Russ

jj79hippy211

i checked fuel pressure at the manifold and its good. how do i test the ignitors? is that the points on the cap or the inner part of the distributor. i just put new spark plugs in a month ago along with a new fuel filter too. i believe it could be the apex/side seals going out (almost at the 180,000 mark) so im looking for a rebuild kit, any suggestions? thankyou guys for helping me with this.

Toofer89

Iv'e just started learning about these motors and haven't even gotten my hands on one yet but I have been doing a lot of reading the last couple of days and it sounds like its the apex seals from what I have read. I would def look into that because if one completely goes and shatters you'll lose the whole engine. The seals aren't too expensive so it's probably a good idea to look into them.

jj79hippy211

yea same here always been interested in them and finally came across one. sounds like a good idea

Aaron Cake

iTrader: (1)

You're aware that replacing apex seals is an engine rebuild, right?

Before assuming there is an apex seal problem (happens a lot less than others would make you think), peform a simple compression test to verify.

jj79hippy211

thanks bro your the first person ive ever heard say that lol ican u do it with a regular compression tester or does it really have to be that digital mazda specific meter?

jj79hippy211

okayy so to anyone who is still paying attention to this. ive timed my car and put a new cap on the distributor still cuts out at 3500 to 4000. can i use a regular compression tester gauge or does it really have to be the mazda digital reader? if anyone has specific details about the best way to time a first gen/test the vacumme and centrifugal advance please let me know

RK53

Hi, I don't know if this matters any more as you've likely fixed the problem by now, but any compression tester will give you a relative reading that will say if they are blown of not. The trick is to remove or at least loosen the check valve in the tester to that it doesn't 'hold' the peak pressure. If you have one broken seal you'll see one 'normal' compression pulse and the two likely very low pressure pulses and a normal one again. With the check valve in the compression tester in place it will mask the low compression cycles.

Typically a motor with a broken seal is a very rough idle and a hard start. The effects are not subtle and WILL NOT only manifest at high RPM and be ok at lower RPM.

Russ