HELP Just got car running and header glows red...

C

cherbi7

New member
1986 rx7 s4 motor s5 intake. Header and complete exhaust all the way back.

I just got my car put together trying to make an autocross this weekend for shake down.

I had to replace the fuel pump, thats all stock except I ran new steel lines 3/8 to the front.

I had a pressure gauge on it when I was diagnosing the fuel pump issue. with the new pump it says I am running 62 psi. That seems high to me and figured the gauge maybe wrong. I think the manual says 42 psi is normal.

Thats the background... The problem is I had the car warming up in my drive way idling about 2000 rpm or so and I noticed my water temp was up to around 200. seems hot for idle. (this car has a huge aftermarket alum radiator on it) Then I looked around engine bay and noticed the header is glowing a dull red. I figure maybe a lean condition could be causing this. I do not have an air/ fuel gauge so I cannot measure that. Does anybody have any insight as to why this is? I would really like to make the autocross so any help would be appreciated. I will be checking this very frequently for any suggestions.

Thanks,
Charlie
 
42 - 45 is normal, and usually 50psi is about right for s4 electronics with a header. Did you do anything to the return line that might restrict flow? You are most likely very rich and the fuel is burning in the header making it glow. Regardless of the fuel pump, pressure is set by the secondary fuel rail as the pressure regulator is on the return line end of it. Check that you do have fuel running out the return. Then wipe out the exaust tip and see if it is a light gray color after running.

PS. Temp at idle should be whatever thermostat you are running.
 
This one's easy (don't ask how I know). The S4 rear iron interferes with the S5 intake. They won't mate without removing some material. So you've got a big vacuum leak and it's running very lean.
 
Ok thanks. I have checked the return line for restrictions did not find anything. Fuel is coming out of it but not that much. That is with the car off and the pump on. It has also developed a random lope where it will not rev over 2500 RPM. I think I may begin to chase an injector issue.
Thanks
 
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