Engine Mechanic Says Sticking Valve Guides

Discussion in 'Fox 5.0 Mustang Tech' started by JasinC19, Aug 26, 2013.

  1. Those stock 120# on the seat springs should be fine they are not heavy like a race spring where I could see having an issue..

    Sent from my XT907 using Tapatalk 2
  2. The TFS guy said he had never heard of valves binding in the valve guides. He said they are machined with plenty of clearance and their QA process 'guarantees' that that wouldn't happen.

    He told me to check my distributor cap! :)

    Could an ignition problem be causing the vacuum gauge needle behavior in my video i posted on Page 1?
  3. What I need is 2 of everything so that I can diagnose like a real mechanic!
  4. A miss could show up on a vacuum gauge, yes. If you're dropping spark every once and a while, you're going to drop vacuum as well.
  5. I'm pretty sure I would feel the need to destroy something if all this time the problem was my distributor cap...

    I put my timing light induction clip on each plug wire to make sure it was flashing properly. Is this a decent test to make sure I'm getting spark?
  6. Just discovered I'm gettin less than 10mpg. Indicative of fuel injector issue?
  7. Not necessarily..... pull the codes

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  8. NO. hook up the timing light only to #1 to check your timing .

    As stated, run the codes and that should most likely tell you where the issue lies.

    Inspect the cap for signs of wear and cracking. Check your wires for signs of burning. If they are old, they could need replacement. To check for spark at each cylinder you can disconnect each plug wire individually and then crank the car, see if you get spark at each end of the wire. Also while running, do a cylinder balance test. If you don't feel comfortable in diagnosing this issue, bring it to any Goodyear or Firestone and have them hook up the car to the computer.

    The low mpg could be due to a misfire or a vacuum leak. Check your plugs.

    As suspected, this "mechanic" doesn't know his ass from his elbow. Do not bring your car back to him. Imagine if you took his advice and pulled the heads off.
  9. Or he does know..... Hmmm. Simple vacuum leak.. Tell him his brand new heads need rebuilt. Cha-Ching!$!$:D
  10. I'll check again, but there were no codes last time I scanned.

    Also, the cylinder balance test came back ok.

    New cap (might have helped a tad), MSD wires are within Ohm specifications.

    I have one of those little fuel injector pulse testers where you hold the needle to the injector as the car is running and it beeps when it fires. The injectors are all firing, but it can't test if there is a leak. I can check out the plugs tonight to see if there are any that look fouled.

    And at this point, if I knew pulling the heads would diagnose the problem, I would have them off the car asap. I'm ready to do it just for peace of mind.
  11. can you post a vid of your car running? Its easier to see and hear what its doing.

    What all is done to the car besides the TFS heads?

    I had a vacuum leak at the tube under the intake, that connects vacuum to the fpr, emissions solenoids and brake booster. Made my car idle all jacked up. you prob already know but your fpr runs off vacuum, when the car is static and the vacuum fluctuates it causes the fuel pressure fluctuate.
  12. If you have one of the hand held vacuum pumps check the brake booster also. Make sure it holds vacuum. Its also a common failure.
  13. I can take a better video, but this basically sums it up:

    I too have the screw in 'tree' under the manifold. At one point, I had capped all that off to eliminate the vacuum leak possibility.

    The car has basically everything done that is required for the H/C/I upgrade:

    255 lph fuel pump
    Ford Racing 24 lb injectors
    ProM 24# MAF

    More, but that might be all that is relevant.
  14. This is just me. I had issues running your setup.

    A tune if you can swing it would probably be the best.

    Where I am CA is pretty strict, and I'm on the fence about the efficacy and long term durability of hijacking and changing signals through the J3 port. It wasnt until I went to a stock 93 cobra maf and stock x3z that things smoothed out for me. That is just my case though. I know everyone is different.
  15. Interesting.. I had thought about the Cobra MAF/EEC swap, but wasn't sure how possible it was.

    That being said, my car was dyno tuned by a reputable tuning shop and made 286 rwhp (Street Burner intake). When I asked the shop why it idled so bad (the main reason i wanted it tuned) they said it was a mechanical issue.
  16. I have a 93 so for me its a drop in. I have read that their are some differences in the harnesses but I don't know what they are and the effect they have. Jrichkers the man on that.

    I'm not saying tuning is bad. I just don't see the chip not causing more problems that its worth 5 or 10 years down the road. More or less.

    I agree though that fluctuating idle indicates something mechanical.
  17. Does your vacuum needle do that like in the vid?

    Someone may have already asked but what about the intake gaskets? Are you running the felpro 1250s or equivalent?

    I know this isn't going to sound appealing, but if it were me I would pull everything and re-do it. Heads, intake and gaskets. Also give you a chance to check out the heads while theyre off. I've had to do it, and it wasn't fun for me.

    When your car is completely cold, how long does it take to warm up? Does it come up to temp fast, like 5 minutes or more around 10 to 15 minutes? Around this time of year. Winter my car takes forever to warm up.
  18. That vid is my car, so yes. :)

    I was using felpro 1250's. Pulled the lower intake to check them, and they were pristine. Replaced with FRPP graphite gaskets.

    To be honest, I'm looking forward to taking the heads off. I'm hoping that once I do, I'll see something really obvious jump out at me.

    Warmup time is pretty quick actually. Not sure if it's 5 or 10.. probably more like 5.
  19. One other thing I kept having problems with on mine was the pcv. I tried both motorcraft and aftermarket grommets and a motorcraft pcv. For whatever reason my pcv is almost loose in the intake grommet. Its been the same on the edelbrock rpm intake and track heat. I had it pop out one time while driving and the car straight died plus other weird drivability issues.

    The only thing I could do to seal it up on mine was to wrap the pcv in self fusing rubber tape to make it tight and seal in the grommet.

  20. You realize that could be the entire problem right there? A leaking PCV valve will cause vacuum leak, causing your vacuum gauge needle to jump, car run rich, and lower your MPG Did you check to see the old screen is out. You sometimes have to use a little RTV around the grommet to get them to seal properly Let it tack up and then reinstall the PCV grommet and valve. Let it sit overnight to cure. See if that solves the problem.