#5 header pipe cold

Discussion in 'Fox 5.0 Mustang Tech' started by cliff88145, Apr 14, 2008.

  1. I started my car the other day and there was a loud banging noise. I went to push the spark plug wires to see if one was not connected all the way. When I got to #5 piston I felt that the header pipe was cold. Every other header pipe was hot. What does this mean? I guess this is where the loud noise is coming from.
    FYI I just replaced the hole top end with the trick flow kit. New spark plugs, wires and cap. Car is a 88 with MAF

  2. Well it means you don't have a cylinder firing. What the cause is is anybodys guess. Did you put twisted wedge heads on?
  3. If you mean I did the work myself than yes. H/C/I
  4. Go back over the fuel injector harness and make sure that particular injector is plugged in all the way. I would imagine that if the plug wire is on, the firing order is correct, and all of the contacts in the distributor cap are correct, it's a fuel related issue. The only other thing I could think of, since you mentioned a banging is the possibility that you have the valves set too tight and they're making contact with the piston. You'd have no compression on that cylinder, so it wouldn't fire, leaving the header tube cold.
  5. OK I just did a compression test on that cylinder and got 130lb from a stone cold engine. That would mean the problem is not part of the valve train right? If the motor was just not getting fuel would it be that loud? I would think it would be a little tick tick noise.
  6. Check the # 5 injector with a noid light for proper operation. Check all the fuel harness connections for that matter.
  7. Well I pulled codes and nothing, then I started the car with the spark plug wire off and it sounded fine, then put the wire back on the distribution with the engine running and the noise came back. This would mean that the cylinder is not getting fuel. Is there a way for to test to see if the injector is getting currant to it (I know that there is a way but can you tell me how and what I need to test it) Would I use a noid light, I have never heard of this thing before :shrug: . The injectors are brand new. Thanks
  8. I went to five auto part stores and finally found the noid light and I performed the test. The injector looks like it is getting power so what does this mean? It must be the brand new injector itself right? So what now, do I just replace it? Has anyone got a brand new injector that has not worked? Has anyone ever had this problem?
  9. if your injector is pulsing and its working right the next thing i would check is the spark plug ! could be a bad one not firing there for not igniting the fuel that would cause the cold pipe! had this happen on my snowmobile this year the one spark plug just stopped working causing loss of power when i pulled over to check it out the cylinder was cold and there was a ton of unburnt fuel in the cylinder ! changed the plug and it fired right back up and ran excellent after that! just a thought if all else is checking out OK! James
  10. It sounds like it is backfiring. That is caused by it only firing only some of the time. Go up and down the cylinders spark plug wire with a screw driver with a jumper wire attached to the metal part of the screw driver and the other end attached to a good ground. This will check to see if the wire has any breaks in the insulation. If it does the spark will jump to the screw driver. Also take the wire off and check the continuity of the wire by puting an ohm meter on it too. Check to see if the cylinder is getting spark first then go to the fuel system. You can check the injector by putting an ohm meter on it to check the windings of the injector. Also check the dizzy cap and rotor. Take the spark plug wire off and put it back on making sure it snaps back in.
  11. Check your timing
  12. Timing is fine. It is getting the spark. When I disconnect the spark plug wire the noise goes away. even tried it with a different spark plug and the noise was the same and pipe was cold. Every other cylinder is fine.
  13. well, when i was trying to pin point a problem before similar to this with a 95 GTS, I pulled up my buddy's 94 GT and started swapping parts.

    now you might not be able to do that, but you could use the same concept. Maybe swap that injector with the number 1 cyclender injector to see if the problem moves with the injector?

    just a thought, and it only takes 10 minutes to sawp injectors...
  14. Well I guess with all the test I ran it has to be the injector. I will try that. Thanks
  15. I'm going to take the valve cover off and check that out too. Can I reuse the same valve cover gasket or do I need a new one?
  16. You should never reuse gaskets, not saying you can't, but shouldn't
  17. Just because you have power and ground does not mean that the injector is working. It just means that it is getting power and ground. I usually use a scope and a low amps probe to verify injector operation. However, I realize that most people don't have stuff like this so you can just use a mechanics stethoscope to check for injector pulses.

    With the "loud noise" I would have first done a compression test. I bet it is a base engine problem (valves hitting the piston). You want at least 100 PSI. Compare your readings to at least 2 other cylinders.

    Also new part =/= good part! I have gotten tons of bad parts (especially from the aftermarket) that were bad right out of the box!
  18. I removed the valve cover and everything looks fine :rlaugh:
    Can I just reset this and put everything back together? Can someone please tell me how to set roller rocker arms (I'm assuming I did not set them up right in the first place) Thanks for the help! :nice:
  19. Probably not. You probably bent the valve and might have damaged the piston. Also I can see debris in the pic (off to the right hand side by the rocker).

    When valves hit pistons it's bad. Mmmkay?

  20. Is the rocker stud broken?

    You really need to pull the lower intake and look at the lifter and cam as well. I willing to bet they're both damaged. As giddyup suggested, I'd pull the head and look at the piston too.

    Trick flow heads/rockers? Trick flow cam too?

    Also, the polylock on that rocker is set in a different position relative to the rocker next to it. Do the other cylinders have a difference in polylock height btw exhaust and intake rockers?