# 1994 Stalling while idling, engine hiccups while driving



## mdweiss (Jan 9, 2014)

Hello all,

I've been experiencing an issue lately with my 1994 manual transmission Nissan Altima with 203,000 miles on it. 

The engine will stall out while idling, particularly at a stop light or in a parking lot, and often within 5 minutes of starting the vehicle (though this may be a concidence). When it stalls, attempts to restart the car are often unsuccessful. When I try to restart the vehicle, the start engine motor always cranks faithfully and strong but it either won't catch or will catch and then die within a few seconds. When it does catch and stall again, the tachometer is flailing wildly. Giving the car a lot of gas does not seem to help the issue. Sometimes I am able to get it going, but other times I have had to have the vehicle towed. The intermittent nature of the issue has caused my mechanic to be unable to diagnose the issue. 

The engine also seems to "hiccup" while I am driving, where I feel the engine loses torque and I notice the tachometer will fall. I've been looking for a pattern to these hiccups, and they seem to occur most often when I am going up or down hills or changing gears, particularly low gears. They also sometimes occur at stoplights, where I see my tachometer drop to about 400 briefly and I can tell the engine sounds physically strained, like it almost stalled out. These hiccups could be small or large, sometimes happening for a small fraction of a second which is barely noticeable, and other times becoming so large I worry the car is going to stall out again. They also seem to go in spurts. Some days my car acts really bad, and other times it seems to not happen at all, suggesting an electrical continuity issue perhaps. I suspect my stall-outs are severe versions of the same hiccup that happened to occur at a stop-light where I don't have the momentum of the car attached to the motor to keep it going.

I believe the problem actually started 3 months ago, although it didn't full out stall and require towing until early last December. I've been attempting to fix the problem on my own, but I am rather new to automotive maintenance and mechanics. This may be completely unrelated, but I feel like this problem started happening during the same time frame my cruise control stopped working. Simultaneously, I notice the instrument panel back light comes on when I brake when it didn't use to do this. I thought I may mention this just in case.

I have so far checked the ECM in the car, and it is reporting a 5-5 no error code. That either means my ECM isn't working right or the problem lies somewhere where the ECM wouldn't report an error. I hope the latter, as I'm not sure if I'd ever debug a bad ECM. The ECM codes on the 94 are very limited, restricting itself mostly to just reporting if a censor is reading as an open or a short. 

I first suspected a poor fuel filter, but that has been replaced within the last month so I doubt it is the issue. 

I then suspected a faulty keyturner that was intermittently failing in the on position, causing the ignition relay to intermittently disconnect, but I installed a bypass switch two days ago and the car has still been hiccuping. I expect it will stall out again sooner or later, as I believe these hiccups and the stalling to be the same problem. When it does, I want to be ready to probe around with my multimeter!

The nature of many of the hiccups seem to be timed when the vehicle is going through some kind of acceleration, deceleration, hill, or some sort of activity that could perhaps shift the engine block. My current suspicion is on the engine ground wire, but I haven't checked it yet. If the ground was intermittently disconnecting, it would likely happen when the engine shifted around on its mounts, which explains many of my hiccup events. 

Further problems I plan to investigate are the electrical connections leading to the fuel pump, fuel injectors, ignition coil, distributor, and assess the quality of the spark plugs. 

Does anyone have any other suggestions and/or have any experience similar to this one that they were able to resolve? Do you think I am going in the right direction with the set of suspicions I have about where the problem may lie? I'd love some advice on the matter.

Thanks!


----------



## smj999smj (Jan 1, 2006)

Remove the distributor cap and look for engine oil. Sometimes the shaft seal will fail, allowing oil to enter into the distributor and interfere with the cam position sensor. Also, check for play in the shaft and do an inspection of the secondary ignition system. These engines were famous for intake gaskets failing causing stalling, but with the erratic tachometer and the symptoms described, I'm leaning more towards an ignition issue.


----------



## mdweiss (Jan 9, 2014)

I removed the distributor cap, and took several pictures at the link below. From my unexperienced eye, everything looked good. I saw no oil in the sensor area. I was a little skeptical about the wear on the contact that rotates around to each spark plug, and may see how expensive it is to repair that part. If I can get it for $5 at a nearby auto parts store, then I'll likely replace it just in case but I doubt it is the issue since it wouldn't cause the tachometer to behave the way it is. 

Car Distributor Photos by toxiktraktor | Photobucket

I did find something suspicious last Friday while working on the car. I mentioned my brake lights caused my instrument cluster to light up. I took my car over to my grandpa's house and we looked at it, and he realized my braking was causing the license plate lights to light as well. We found that one of the double filament bulb sockets in the rear brake light had somehow shorted. The two filament positive connections were shorted in the socket and this was causing these two circuits to connect, causing this behavior in the car. The ground connection on the socket was also melted with obvious evidence of a excessively high current flow in this area. The plastic screw post had melted down such that the ground connector disconnected from the metal socket. I'm wondering if this ground connection was periodically making contact with the bulb socket and causing a short. This could be the source of the problem, as who knows how a short circuit would interrupt the cars operation. We repaired it and since then I haven't had any engine hiccups, but I also haven't driven the car enough since then to be convinced the problem is solved.

What do you think of the distributor cap pictures? 

When trying to get the distributor shaft head off of the shaft, I was unable to rotate the shaft by hand to get to the screw which was facing in a direction I couldn't unscrew it, and had to run the engine to rotate it into a better position for me. It wouldn't shift back and forth any, at least by hand. 

What do you mean by the secondary ignition system? I'm unfamiliar with it, and couldn't find it in my shop manual.

I plan to drive the car more today and see if I get any more hiccups. I'm keeping my fingers crossed it was that socket short that was doing it, but I'm not confident yet.

Thanks for your help!


----------



## smj999smj (Jan 1, 2006)

It's not uncommon for the brake bulb contacts to melt over time and create a short, which causes voltage from the brake circuit to cross to the parking lamp circuit and vice-verso. It should not cause the engine to "hiccup" or misfire. 
Secondary ignition system is your plugs, cap, wires, etc.
The cap and rotor do appear to have significant wear to them. Aftermarket parts are not recommended on most Asian based vehicles, like Nissan. It's always worth the couple of extra dollars to stick with genuine Nissan or the OEM supplier of those parts. In the case of the distributor, the OEM manufacturer is Hitachi. When it comes to spark plugs, it's NGK. NGK is also a good brand to go with when replacing ignition wires. One thing I noticed on your pics is that there seems to be an issue with the cam position sensor, or the "pick up" that reads the sensor ring inside the distributor. The sensor, itself, has solid state electronics. It looks like there might be some wiring coming out of it and/or there may be some overheating. This might very well be your issue. Unfortunately, this sensor is usually not sold separately and requires replacing the distributor assy. I usually prefer genuine Nissan remans, but they go for over $400. If you need one, I might go with the Hitachi reman available at Rockauto.com for $172...but there's only one left so if you need it, I wouldn't wait around to get it. Most distributors also include the cap and rotor, so I would hold off on replacing the cap and rotor until you're sure you don't need a distributor assy.


----------



## mdweiss (Jan 9, 2014)

I took it for a couple more drives today and it hiccuped a few times, but thankfully no stalls or severe episodes. The shorted socket wasn't the issue.

I went ahead and ordered the Hitachi D4P9003R (D4P90-03R) distributor off the website, and it should be here in 4-5 business days! Come to think of it, I don't think I've ever had the distributor in the car replaced. I've had the vehicle for 10 years, as I got it in my 10th grade year of high school from my uncle for $1000 (good deal!) and I don't think he had the distributor replaced either, so it is potentially 20 years old. I have, however, had the spark plugs replaced in the car in the past year and they are pretty much brand new along with the wires leading to them. I may go ahead and check them as well just in case. 

The camshaft sensor does seem to have a molten plastic point on it. I'm glad you're here to look. I didn't even notice it when I looked this morning, but luckily my camera did. I may go ahead and take another look at it and see if I can get a better picture when the new part arrives since I'll be swapping them anyways. 

When the part arrives I'll install it and let you know if the problem is resolved!


----------



## mdweiss (Jan 9, 2014)

Hey, just wanted to give you an update on some interesting information I found about my car today. The distributor arrives tomorrow. 

It stalled on me in my neighborhood this morning. I got out and unplugged and plugged back in the distributor wire a few times and hopped back in. It started back up!

I then got a bit curious. When I got home today, I poked at and pushed at the connector a few times. Upon doing so, I got the engine to sputter a couple times. A prolonged push caused a stall. 

I waited for the engine to cool down (all of my stalls are near start-up it seems like), and the connector was much more sensitive to touch. Pushing in one direction seemed to cause the connection point to fail and the engine sputtered and started to die. I could do this repeatedly. 

The problem is here in this connector! The distributor is half the connector, and I will likely try and clean up the other half a bit when I install it tomorrow. I feel this has given me great confidence this connection point is the specific issue.


----------



## mdweiss (Jan 9, 2014)

I put the distributor in last friday, and have driven the car for about an hour and a half since. It hasn't showed any more symptoms described above. I think it is fixed!

Thanks for your help! You may've just saved me from having to get a new car.


----------



## jbilletmdweiss (Jun 14, 2014)

Have your ignition coil(s) checked. Sounds like one or more may be weak or failing.


----------

