Hey, 

I just put some 3-2 headers on my 78 EFI z and once I cranked it over and got it warmed up, it doesn't run right. I have 32 psi fuel pressure, labeled all connectors and lines when I took them off. I can't see where I went wrong. 

It is running extremely rich, will not rev, needs gas pedal to start. It sound like I am missing spark but I'm not sure how this would have happened? I didn't touch the distributor at all. Thoughts?

I can post some pictures of the engine if that would be helpful. 

Intake manifold leaks...maybe. Although I would suspect lean not rich on manifold leaks

Edited January 2, 20196 yr by Patcon

7 minutes ago, Patcon said:

Intake manifold leaks...maybe. Although I would suspect lean not rich on manifold leaks

my thought exactly. My foot needs to be on the gas for it to run at all. It runs so rich theres a cloud behind the car. 

22 minutes ago, Pochie45566 said:

78 EFI z

It would help if you could add a lot more detail.  Many possibilities. 

Sounds like your coolant temperature sensor is unplugged or on the wrong terminal.

Just now, Zed Head said:

It would help if you could add a lot more detail.  Many possibilities. 

Sounds like your coolant temperature sensor is unplugged or on the wrong terminal.

 I just swapped the two, and no change. Still does not want to start and runs horribly. 

It is a 78' 280, Stock EFI system, new injectors, water temp sensor, maf, AAR. It ran fine before the headers and had no issues. It just now idles low, doesn't want to rev, runs rich. I got new studs when I did the system so none of them broke off and all are torqued down pretty well. I checked for any spots air could be getting into the fuel lines because I did have to take off the rail. Nothing came up. 

Edit - misread your message.  

If you have a meter, your most effective troubleshooting will probably be at the ECU connector in the cabin.  Get The Fuel Injection Book and start probing.  Something will show up.  Good luck.

p.s. was the 32 psi with the engine running or not?  Check the FPR vacuum hose for fuel.  Maybe your FPR went bad.

Edited January 2, 20196 yr by Zed Head

Could also be a pinched/shorted injector wire.  It will cause the injector to stay open.  That will show up on the ECU connector test also.

What do plugs look like? Soot?

18 minutes ago, Zed Head said:

Edit - misread your message.  

If you have a meter, your most effective troubleshooting will probably be at the ECU connector in the cabin.  Get The Fuel Injection Book and start probing.  Something will show up.  Good luck.

p.s. was the 32 psi with the engine running or not?  Check the FPR vacuum hose for fuel.  Maybe your FPR went bad.

The 32 PSI was with the engine off. I did have to mess with the FPR a bit to get it to clear the throttle linkage maybe I messed it up. . I will go in there and do the component checks stated in the EFI bible. 

Just now, 240260280 said:

What do plugs look like? Soot?

Considering I haven't ran it enough to foul them I think they're ok but yes, sooty. 

3 minutes ago, Pochie45566 said:

The 32 PSI was with the engine off. 

36+ is spec.  If you had a hole in the FPR you might get a lower reading but fuel pouring in to the intake manifold.

Pull the vacuum hose and run the fuel pump.  See if the FPR squirts fuel from the vacuum fitting.

Check connections and wiring  to coolant temperature sensor.