Dies when put into gear

Discussion in 'Classic Mustang Specific Tech' started by t_chelle16, May 16, 2007.

  1. I have had an on-going problem since about the 3rd month that I've owned this car (bought it Nov 2005) and quite frankly, I'm about ready to set the stupid thing on fire or at the very least throw a bunch of rocks at it.

    It will start up okay and idle okay, but as soon as I put it into gear, it will die. Sometimes it can take 3 - 5 attempts just to get backed out of the driveway and another 1 or 2 to get it into drive once I'm backed out. I can even let it warm up for a few minutes (until the temp gauge starts to move off of the cold mark) and it will still die. Once I've been driving around for a while (like 5 minutes or so), I can generally park, then start it up again, & put it into gear without too much trouble (sometimes it will die or act like it wants to die, but about 80% of the time, it does okay).

    My dad and I have tried tweeking the carb, adjusting the timing, rebuilt the carb twice, tried a different carb, replaced the intake manifold gaskets twice (vac leaks), reverse band adjustment, tried different set ups for the PCV system, and even replaced the engine with a remanufactured long block (this problem was one of the main reasons I went to the expense of getting a new engine). And no matter what we do, it will fix the problem for anywhere from 1 - 5 days, but after that it comes right back and the longer I let it go before fiddling around with something else, the worse it gets (I think my record is about 10 restarts just to get out of my parking spot at work). It will eventually get to where any time I'm stopped at a stop sign or red light it will try to die and a couple days ago I was just driving down the road at about 20 mph and it just died.

    I just spent the last 6 months, a couple thousand dollars, and buckets of blood, sweat, & tears (literally) and I still can't even drive the car. What else could there possibly be on that engine and could be doing this? Or could it be something with the tranny? I'm seriously at my witt's end here and I'm beginning to really hate this ****ing car.

  2. Could be a bad torque convertor, tranny, or possibly your ignition (since you said it was doing it while you are driving). I would check to make sure that your coil and ignition box are good along with the rest of the ignition first, then check out your driveline. If you have a lock up torque convertor and it is locking up while you are standing still it will cause the engine to stall. Personally I would look at the ignition first.

  3. My 66 vert does that when it's cold, I just give it a little gas when I put it in gear (with my left foot on the brake) but once it's warm it's fine

    It's really strange that your car would up and die while driving it :shrug:
    Sounds like you've tried everything but the trans...
  4. What kinda carb does it have? Is it an electric choke or the kind with the tube going down to the manifold?

    Kinda need some more detail on your car, year, engine, what is and what is not stock.
  5. Oops, forgot about the details. It's a 67 with a 302 with stock internals (I believe the old engine was pretty stock internally too). Edelbrock Performer 289 intake (I actually have two of these that I've tried. One ended up being warped, but this one is fine). The carb (both carbs, actually) is an Edelbrock 1406 4 barrel with electric choke. Tranny is an XP/C4 (stock as far as I know). Electronic ignition that the previous owner put in (Flamethrower, I believe). It's not a locking torque converter.

    I tried that and sometimes it will work, but not often. And even when it does work, it generally dies at the stop sign 1 block from my house.

  6. i hope that when you set the idle speed, it was done with the trans in gear, and the vacuum disconnected and plugged. idle speed should be 750-800rpm
  7. Is it dying at idle?

    Can you set the idle up a bit?

    I had to do this to mine until I finally got the timing and carb working together.
    Turned out that my timing was off because the outer ring of the harmonic balancer had shifted a few degrees. I had to manually find TDC and mark it and then I re-set the timing with a timing light w/ an advance adjustment. Once that was done I could lower the idle again.

    I have a new balancer ready to go on when I get the time.
  8. I actually let my dad do most of the adjustments on the carb (I suck at it), but I'm sure he did it right. I'll ask him to double check, though.

    And right now, in park, it idles around 900 - 1000, rpm.

    I replaced the harmonic balancer when I put the new engine in.

  9. then your idle speed is likely a bit too low in drive, and that is why it is dying.
  10. How many RPM does the engine drop when it is in gear vs in park?
  11. When I tried it today, it went from 900 - 1000 in park to around 500 or 600 in gear (it died pretty quickly so that's a close guess).

    I'll go try bumping the idle up a little more.

  12. That is way too much of a drop in RPM, I bet you have a vacuum leak somewhere... How does the car run when it is driving at WOT, does it Ping?
  13. My dad had the vacuum gauge hooked up to it the other day when we put on the newly rebuilt carb and he said there was good vacuum (I think he said 22). Of course, that was a few days ago and it ran fine then. It always takes a few days for it to start messing up again after we do something.

    And no pinging. At least not the last time I was able to drive it.

    Dad's been working mid shift so he's asleep right now, but when he gets up, I'll have him come out and help me look everything over again and check the vacuum again.

  14. What did you set your timing too? It might be set tooo low, thus creating no power at idle, thus causing it to die.
  15. Timing is set at 10*. I think the shop manual says something like 6* or 8*, but that seemed too low so dad set it at 10*.

  16. i have mine set at about 12-14. also, i'm betting that your gas tank is full of rust and that the fuel lines and filter are partially clogged with crap from the tank. i would replace the gas tank and put on all new rubber lines at least and preferably the metal lines as well or at least blow them out real good. did you replace the fuel pump when you installed the new motor? if not you may want to consider that as well but at least check it and make sure you're getting flow from it. you should be able to fill up a 1 gallon gas can in under 30 seconds.

    judging from the park idle RPM and the in drive idle RPM i'd say you either need more timing or you still have a bad vacum leak. does the car have power brakes and if so do they work right? meaning does the booster make that wooshing sound when you step on the pedal indicating a vacuum leak. just went through that on my jeep cherokee. i knew the booster had been bad for a long time becuase the power brakes didn't work at all. it didn't really effect the idle speed much when stopped at a light with the brakes on but it did cause the truck to smoke at idle once it had been running for a while. i guess what was happening was the computer was seeing a lean condition so it would compensate by adding more fuel, making it run really rich at idle and therfore making it smoke. replaced the power booster and no more smoking problem.

    the point is, you may think one thing doesn't affect another but it actually could. in my case i killed 2 birds with one stone; my brakes work again and my truck doesn't smoke anymore.
  17. To add more confusion to the booster idea, my vacuum booster died a few months after I bought my 67 coupe. It just wouldn't idle at all, and I had it set around 1200 rpms (4 speed stick) and the brake pedal was hard as a rock. I literally had to pull over in a parking lot and bump the idle up to 1500 just to get home!

    This may not be what you're going through as you mentioned that it died while you were driving, but then if you were coasting with foot off the go pedal, this might be a logical reason. Good luck.
  18. Alrighty, might have solved the problem(s). But first I'll answer some questions just in case.

    I'm not sure what condition the gas tank is in, but I will keep that in mind (clogged filter/fuel line/condensation in the gas was one of my mom's guesses as well). I did get some Heet a while back to dump in the tank because it was sitting for 6 months while I replaced the engine, but I haven't gotten around to putting it in yet.

    And yeah, the fuel pump is one of just a couple of things that I didn't replace with the engine and I probably am going to replace it sometime in the near future.

    And no power brakes.

    Now to what we think the problem could be. (to make things a little easier to explain, I'll call the carb that was originally on this car Carb A and the one that came off of Sadie Carb B - they're both the same model carb, though). Carb A is the one that I rebuilt (by myself) a few months before replacing the engine. Rebuilding it didn't help so I replaced the engine. I had plans to rebuild Carb A again, this time with Dad's help/guidance just in case I did something wrong the first time and that's what was causing the problem. However, when we put the new engine in, we put Carb B on there because we knew it worked okay on Sadie and we didn't want to break the engine in on a freshly rebuilt/untuned carb. We left that one on and after a few days the dieing problem came back.

    So, we rebuilt Carb A for a second time and put it on. Car ran okay (not great, but okay) for a day, but started dieing again. So dad looked at it again and firgured that maybe the pcv system wasn't set up right. It had a breather on one valve cover and a hose going from the other valve cover to the back of the carb (this is the same way we had it set up with Carb B). So he disconnected the hose from the back of the carb and plugged that port. This is when he got the good vaccuum reading. Ran okay for about a day, but started dieing again after that.

    That brings us up to yesterday. I got dad out there looking at it again last night and he noticed that he could back the mixture screws out all the way and the engine kept running right up until the point where the screws were removed completely.

    So dad's theory is the problems we had up until the engine replacement were a combination of a vacuum leak out the back of the carb/pcv system set up wrong and those mixture screws (bad idle jet). When we put Carb B on there after the rebuild, the idle jets were fine, but we still had that vacuum leak out the back. And when we put the rebuilt Carb A back on there and fixed the vaccuum leak out the back, we still had the bad idle jets.

    So, I just got done swapping the carbs out again. Carb B is back on the engine with that vaccuum port plugged up. I fired it up and so far, so good. The idle still drops down to around 600 rpm when I put it into gear, but it sounded fine and didn't try to die (and I didn't really even let it warm up all that much before trying to put it in gear - just enough to get fuel flowing back through the carb good). If it does good, then I'll probably take all the new parts from the rebuild kit off of carb A and put them on carb B (basically rebuild carb B without shelling out another $50 for a 3rd rebuild kit)

    So, does anyone want to start a pool for when my car will start dieing again? Or do those two things sound like they could be what was causing all the problems.

  19. Wow that was confusing, so where was the vacuum leak?
  20. At the back of the carb.

    In this pic (not my carb, I stole the pic off of ebay), where that nut looking thing is sticking out of the middle of the back; mine has a barbed thing there that a hose can connect to. We originally had a hose running from there to the valve cover cap, but now we have it capped off.
    View attachment 385359