Jumping outa gear, racing throttle????

joesplace62 · 01-03-2003, 09:58 AM

Yesterday, on my commute to work I heard a clunk from the right rear of the car as I decellerated to a stop light Shortly after that as I accelerated down the road, I heard another clunk. Very similar to the noise wire wheels with worn splined hubs make. Don't know if these events are related to my real issue. As I went home last night, the car was running fine and I didn't hear any noises like the ones I heard in the morning. However, as I pulled into my driveway, the car made a LOUD thump and jumped out of gear with a bunch of noise (grinding and thumping). Thought maybe I didn't get it completely into first gear. Put it back into first and let the clutch out gingerly, boom, same thing. At this point I'm thinking broken axle. I left the car idleing and pushed down the driveway towards the garage. After pushing it 30 feet or so while still idleing, the engine does one quick rev up and then settles back down to idle. Now I'm thinking somethings messing with the throttle linkage.
I get under the car and look at the axles, look OK, so I open the engine compartment and check out the throttle linkage. It looks OK too, then I notice back against the fire wall on th drivers side of the car, there is a 1/2" wide cogged belt sticking up through the sheet metal against the fire wall right next to where the throttle linkage comes thru the fire wall. The belt has about a ten inch long loop in the engine bay and I wasn't able to remove it from its location.
I started the car again and tried putting it into gear. It jumped out of gear as before on the first attempt, then behaved normally on the second. As I was carefully idling it into the garage, the engine with no warning, zoomed up to redline on me. I shut it off instantly and tried restarting it again. Idled just fine til I started moving forward again and it revved again. I shut it down and put it on jack stands to get a better look. Couldn't see any sign of the other end of that belt from under the car. Also couldn't see anything fouling the accel. linkage or shifter assembly.
Is this belt some road trash I picked up or is there a belt on my '72 2.4 T motor that I know nothing about?

Any ideas would be much appreciated. Marty

Rot 911 · 01-03-2003, 10:05 AM

Marty, long time since I have heard from you! That cogged belt goes to your mechanial fuel injection pump. Without the belt no fuel is pumped to the injectors. Is the belt still in place or did it jump off or break? In either event this would not cause your engine to zoom up to redline. I suspect something is interfering with the throttle linkage. Pull off the air filter housing and take a look around. As to the car jumping out of gear, could be a lot of things. From a broken motor/transmission mount to bad shifter bushings to gearbox problems.

joesplace62 · 01-03-2003, 10:10 AM

Good to hear from you, Kurt. I've been searching the archives and saw a post about that belt. However, I'm a carb guy. Would that belt still be in place if the MFI is gone from this motor? What drives the pump? Thanks for the reply, Marty

Rot 911 · 01-03-2003, 10:33 AM

Something is definitely not right there Marty. If you have carbs there should not be any cogged belt. The MFI pump is run off a gear on the end of the left side cam. The gear might still be there after a carb conversion, but I can't believe anyone would leave the belt back there! In this pic, which is not the best, if you look close you can see the MFI belt in place.

widebody911 · widebody911's Garage

The MFI pump is driven from the left camshaft. If you have MFI and this belt breaks, you're dead in the water. If your MFI was removed, I have no idea why this belt would still be present.

As the the jumping out of gear, sounds like your transmission is toast. There's a slight hail-mary chance that your coupler has gone south, such that you're not getting all the way in gear. If that's not the case, you're in for a very expensive new year. I had this happen to me. In my case, the synchro *broke*, and bits were floating around in the transmission, causing all kinds of mayhem. In neutral, sitting in the driveway, the car would buck and shake. It was kinda scary to watch - like something out of a Stephen King movie...

widebody911 · widebody911's Garage

I wonder if it's possible for the belt to split lengthwise, so there's a 'narrower' belt left on the gear to continue to run the pump.

joesplace62 · 01-03-2003, 11:06 AM

Thanks for the replies, guys.
Kurt, that belt looks just like what I found in my engine bay. I had that motor installed 4 years ago and never saw any sign of it in there before. I wouldn't have believed my wrench would have left it there after converting the motor to carbs. Just goes to show, if you want something done right you have to do it yourself!

Thom, I blew up a tranny a few years ago also, and put in a used one. The car still seems to shift into all the gears OK and was able to move under its own power into the garage. It also doesn't make any unusual noises while idling in neutral. I put a new coupler in the shift linkage last summer and have looked at it a couple of times since then, so the cheap possibility doesn't seem likely.

I'll be pulling things apart this weekend, we'll see what we find.

Thanks again, Marty

Rot 911 · 01-03-2003, 11:17 AM

Quote:

Originally posted by joesplace62
Thanks for the replies, guys.
Kurt, that belt looks just like what I found in my engine bay. I had that motor installed 4 years ago and never saw any sign of it in there before. I wouldn't have believed my wrench would have left it there after converting the motor to carbs. Just goes to show, if you want something done right you have to do it yourself!

Here is something to think about. Assume your wrench left the belt just hanging there and the cog for the pump was still attached to the cam, but the other cog is gone along with the MFI pump. The cam cog is always spinning every time the car is running. Now suppose the belt which was hanging there, but not touching the cog actually came in contact with the cog for some reason (maybe you hit a bump, maybe gravity, who knows) anyway engages on cog and with no MFI Pump cog to attach to just starts whipping around. Comes into contact with throttle linkage, grabs linkage, red lines engine. While this sounds crazy, who knows?

joesplace62 · 01-03-2003, 11:22 AM

Kurt, Doesn't sound crazy to me. I was just saying exactly that to my co-worker here. Do you have my place bugged?

I'm cutting the belt off as soon as I get home and we'll see if that helps.

Marty

widebody911 · widebody911's Garage

At the risk of sounding pedantic, are you sure you have carbs? I just can't see someone going thru all of the effort to remove the MFI pump, throttle bodies, linkage, etc, and leaving the belt. To quote Johnny Cochran "It does not make sense!" No offense, but a lot of people think MFI stacks look like carbs.

widebody911 · widebody911's Garage

Quote:

Originally posted by joesplace62
Thom, I blew up a tranny a few years ago also, and put in a used one. The car still seems to shift into all the gears OK and was able to move under its own power into the garage. It also doesn't make any unusual noises while idling in neutral. I put a new coupler in the shift linkage last summer and have looked at it a couple of times since then, so the cheap possibility doesn't seem likely.

With a bad synchro, you will be able to shift into the gears, ie there's nothing physically preventing the actual shift operation. However, the second you put a good load on it, it will pop out of gear. Some people have milked some extra life out of them by being super-gentle with the gear in question, or even holding the shifter (bungee-ing 4th on a VW is common) but when it's broke, it's broke.

Rot 911 · 01-03-2003, 11:52 AM

Quote:

Originally posted by widebody911
At the risk of sounding pedantic, are you sure you have carbs? I just can't see someone going thru all of the effort to remove the MFI pump, throttle bodies, linkage, etc, and leaving the belt. To quote Johnny Cochran "It does not make sense!" No offense, but a lot of people think MFI stacks look like carbs.

Thom, good point! I've seen Marty's car a couple of years ago and it seems like he did have carbs. Anyway just to make sure here is a pic of my old 72E engine with the MFI pump circled. Oh and if he did have MFI and the belt came off, I can guarantee you that his engine would not idle, much less redline.

joesplace62 · 01-03-2003, 12:07 PM

HA HA! Yeah, I've got webers. You're right though, I can't believe he left the belt on the car. I called my old wrench and he said "I've left hundreds of them on. Why cut a perfectly good belt?" That kinda left me at a loss for words for a minute there. Seems kind of stupid to me. He did say there may be a conflict between the accel. linkage and the clutch cable, if its not threaded in there properly. Of course he installed the last two clutch cables I've had put in.
I'll further investigate the transmission issue once I figure out the revving problem. Seems weird that they may be completely unrelated.
Marty

RichMason · RichMason's Garage

Having just changed my MFI cam seal and belt on my 69E, I don't think you would have to cut the belt or remove the sheetmetal to remove it - turn it sideways and ease it around the front of the MFI/cam pulley. Sounds like poor attention to detail.

jkeyzer · jkeyzer's Garage

Yeah, that is completely half-ass work. Sorry.