Runs fine in neutral & reverse, but won't go forward???

I have to admit my first reaction is that you are having some fun with folks on the site but it's not April Fools day (do they have something similar in SA on Oct 22?)

Reverse is a much lower gear than first so there would be more load on the engine in first than in reverse and really REALLY bad secondary ignition problems MIGHT be able to cause it. But if it can't go downhill in first either, that doesn't seem likely.

Maybe the engine's forward/backward sensor is faulty? Sorry, couldn't resist...

It'll be most interesting to hear the cause/solution.

 

What about second gear? Does it run well there?

Only thing I can think of that is different is that your backup lights are on in reverse. But you say it revs well in neutral.....

 

Does it rev freely in 1st gear with clutch depressed? Curious if the rods are interfering with something. Curious about the 2nd gear question. If interfering with something electrical, 2nd might work fine.

 

Well, there is no way the engine "knows" whether it's in reverse or forward so it seems to me that it has to be somehow load-related since the least loaded gear would be reverse. THe things that come to mind that can affects how an engine runs when loaded as opposed to not loaded is the ignition system itself (secondary, usually) ignition timing and valve timing. But even at that, this seems really extreme. I would expect 1st would do OK and the problems would show up in the higher gears at higher loads.

Can you check the ignition timing to see if it's in spec?

You mentioned that the car was started/warmed up in your absence. Is there any way that a cam could have shifted - bad belt maybe?

I can't think of anything else that could cause these symptoms...though I have seen ign coils do some mighty strange stuff. Saw a car that cut out in left turns due to faulty coil...

THe fact that it coughs/sputters immediately when you engage the clutch in first is a real stumper. Will it idle down the road in first?

 

Weird! I am also curious if it will idle down the road in 1st. If so, give it a little bit of gas and see what happens. Take note of what RPM it will start to sputter at. As soon as it starts to sputter, push in the clutch and see if it will rev up.

Sounds like it might have something to do with the G-Force of moving forward. (Even if it's only a small amount) Maybe a wire is moving or something electrical is shorting out when you move forward?? Maybe the fuel pump is cutting out when moving forward? How's your gas level? Maybe if it's exceptionally low, the fuel is sloshing away from the pick-up when moving forward and towards the pump when going in reverse??

Please let us know what you find out. It doesn't sound like there's a major problem with the engine since it runs well with no load.

 

I was going to say that I cannot imagine what reverse lights could possibly have to do with it but had a friend that had an old MB that when you turned on the WW wipers, the radio would come on/off as the blades swept across so electrical malfunctions can get pretty darned weird!

Part of what makes this so confusing/interesting is that the car ran fine (right?) when put away and now doesn't. So one thing would be to think about what could have happened while it sat.

I really hate shotgunning and admit that now I'm just shotgunning but any possibility of mice/whatever chewing on some wiring while in storage? THe engine torques slightly in it's mounts and it twists the opposite way in reverse than it does in forward. Maybe along the lines that Bxtech noted, there is a wire that is coming into contact with ground when the engine torques in forward gear Unless an engine mount is broken, the torquing movement shouldn't be much but maybe that combined with a broken/uninsulated wire....

Just to verify - the last time before storage, the car ran normally with no sign whatsoever of this sort of behavior, not even a slight bit of it, right?

This added - again related to engine loading...what about the gasoline? If it was badly degraded it could work fine at no load but have a problem with load.

I'm loading up with number 9 shot now.

 

Wouldn't make sense about the reverse lights if it runs fine in neutral. Reverse lights are not on at that time. If you suspect a ground problem..........maybe try running a temporary ground from the chassis to a nut or bolt on the engine and see what happens.

Does the engine rev up and run fine in first gear with the clutch pushed in with no load? As soon as it starts to sputter from trying to move forward from a standstill..........what happens when you push the clutch back in and take the load off? Does it run smoothly again?

Try the temporary ground wire. If that doesn't do anything, I still gotta a feeling that it has something to do with the forward motion of the car. Fuel pump or something else electrical must be shorting or cutting out from the motion.

 

My thought is that it is not really in 1st, but more likely 3rd or 5th. Something's up with the linkage.

Dave

 

I too think there is either a problem with the linkage or the transmission. I would think if there was an electrical issue it would be present in neutral, reverse and forward. If it was me I would get her up in the air and make sure she is actually shifting into the proper gear. Could just be a worn out linkage or something has come lose. Good luck.

 

I don't have access to your schematic but, I would open the shift gate (two screws) take out the small two gauge instrument cluster (two screws) and see if the reverse switch is loose and making contact with something it shouldn't when not in reverse. You will have complete access to the switch so you could also pull the leads off the switch and see if the lighting circuit has anything to do with this or if it is mechanical in nature relating to the shift linkage in contact with something underneath. So, four screws and a lot of rule in/outs. Good luck.

 

This was my thought as well. The linkage forks on my 328 went loose right after
I bought the car - same symptoms - reverse was fine, but the 1st gear position
was actually 4th or 5th. Same scenario - drove into the garage just fine the day
she was delivered, but 3 days later would only go in reverse.

Jedi

 

My money is there too... especially because OP answered the question about whether it's being in "first" that makes the engine run poorly or putting the clutch in:

 

+1

 

I guess anything is possible but how does something go wrong with mechanical linkage while a car is just sitting?

But it does bring up the question of the running while you were absent...what exactly did the person do that started/warmed it up?

 

Have you looked at your brakes? In particular, the parking brake. Perhaps something has come loose, like a brake pad, and when you go in reverse, it's being pushed away from the caliper, but then in forward it becomes wedged, causing the car to bog down. As others have noted, the engine shouldn't care whether you are in forward or reverse, and if it revs fine in neutral and works in reverse, it's not the engine. So that leaves either something going on in the transmission, or something else stopping the car in forward. Brake problem seems like a possible suspect to me.

Just a thought. You might try jacking the car up and spinning the wheels in both directions and see if anything is hanging up. Remember to put the car in neutral and release the parking brake when you try to move the rear wheels. And they don't spin as free as the fronts because of he differential, but you should be able to see a difference between forward and backwards when you spin them, if there is a problem.

 

My money is there x3.

If the gear engagement fork in the tranny slipped even slightly because one of the connecting bolts came loose, this would make perfect sense.

 

Well, I agree that if the tranny is "stuck" in some higher gear it could produce symptoms that might be described that way. But the symptoms of trying to start the car moving with the tranny in say 3rd or 4th gear would be fairly easy to recognize (since I'm sure we have all done it at some point in our automotive lives).

If I understand the description, that's not what I'm hearing. "Coughing and sputtering" is not how I would describe the symptoms of starting off in the wrong gear but OTOH, that's the downside of long-distance diagnosis. One person's description of a symptom can be quite different than another person's description/understanding of exactly the same symptom.

I have to admit that being in the wrong gear is a more likely possibility than some of the other possibilities but...how did it get that way? The tranny/linkage didn't "break" by just sitting there...

 

Mine did. One day fine, the next day all goofy. Of course, they had not been
tightened properly by the previous owner who had them adjusted just before
I bought the car from him.

Jedi

 

The shift shaft is 3 pieces.

IF one of the turn buckles that holds the three pieces came ever so slightly loose ......


Once you have popped the tranny pan off you can see how a host of things can go wrong EASILY, even though it is a VERY simple conglomeration of a few metal parts.

 

I didn't read all of the replies so sorry if this has been said.

The first thing that came to mind to me was not the tranny. The engine wouldn't spit and sputter even if it was in a higher gear.

I think it is an intermittent electrical issue that is caused by the engine torque movement in a different direction. Of course the engine is going the same direction but the entire assembly will be torqued differently.

Just my $.02

GT

 

"I didn't read all of the replies so sorry if this has been said."

Yes, it was said by several people but I agree with you. To me the description of the symptoms do not fit starting out in the wrong gear. But, as noted, we all have different ways of describing things so MAYBE that's part of the issue. I would describe what happens when you engage the clutch in a manual car from a stop in a high gear (assuming it didn't just stall immediately) as "bucking" or "jolting" or something similar - more of a mechanical thing than sputtering. But that's just me.

In any case, it will certainly be interesting to find out what the problem is!

The fact that a Ferrari tranny linkage could fail while just sitting there for several months is a whole different (and scary) deal. But, after all, it is just a Fiat in fancy clothes!