Car was sputtering on highway, now worse, driver relays click very fast,vehicle death

[jt1583]

A few days ago I had some sputters and hiccups on the highway, thought nothing of it, although it was a new issue. Then I went over a transition on highway and it seemed to coincide with that so I thought it was physical (ground or sensor wire maybe).

When I started it today, the relays at the driver footpanel were clicking very fast, and when the ones down by the ECU started clicked the car died. I don't think it's the relays themselves, because even if I swap them around, they still click, very fast. It seems either ECU related or power supply related. What are the ground wires to check?

I pulled the codes, getting

14 - speed sensor
34 - knock sensor
41 - intake air temp
82 - crank position
105 - EGR

all these are correct except crank position, which I've read is monitoring only. The other sensors actually are missing for the most part.

It's a 95 S14 with a 3C ECU and pretty stock KA24DE. Fuel pump seems to be priming and running okay. Everything under the hood still looks tidy although this could be a grounding issue. No multimeter available to check battery/alt status, I'll work on that.

Any advice very welcome, thanks in advance.

[FlatBlackIan]

You are most likely correct with the ground issue.

IIRC, there is a ground on the intake manifold, and one behind the pasenger headlight, by the fuse box. There is a third one, but i cannot remember where.

One of them provideds the earth refference for the ECU and its sensors. If loose, it will cause all sorts of wacky issues.

[jt1583]

Did this and it worked for a little but the problem came back quickly.

I drove it around town and I can fight the dropping RPMs by revving the gas until a certain point but if it wants to die it will die. The last time it died pulling onto my street and the battery and brake light illuminuated, don't these two together usually mean the alternator could be bad?

[slider2828]

Check grounding on the ecu.... on grounding oh alternator points.

[ka4life87]

Is it an s13 or s14 ka? If its s13 then if ur getting crank signal code then that will cause driveability issues, on s14 ka crank sensor is for diagnostics only not engine performance

[steve shadows]

Originally Posted by jt1583

A few days ago I had some sputters and hiccups on the highway, thought nothing of it, although it was a new issue. Then I went over a transition on highway and it seemed to coincide with that so I thought it was physical (ground or sensor wire maybe).

When I started it today, the relays at the driver footpanel were clicking very fast, and when the ones down by the ECU started clicked the car died. I don't think it's the relays themselves, because even if I swap them around, they still click, very fast. It seems either ECU related or power supply related. What are the ground wires to check?

I pulled the codes, getting

14 - speed sensor
34 - knock sensor
41 - intake air temp
82 - crank position
105 - EGR

all these are correct except crank position, which I've read is monitoring only. The other sensors actually are missing for the most part.

It's a 95 S14 with a 3C ECU and pretty stock KA24DE. Fuel pump seems to be priming and running okay. Everything under the hood still looks tidy although this could be a grounding issue. No multimeter available to check battery/alt status, I'll work on that.

Any advice very welcome, thanks in advance.

Definitely sounds like an electrical short on one of the major input wires into the ECU or behind that kick panel. See this time and time again on 240sxs.

[idlafie]

Check the ground wires located on the exhaust manifold side of the motor. The ground wires are connected to a metal eyelet & that eyelet is bolted to the engine block towards the rear of the motor close to the firewall. The ground wires are above the area where the oxygen sensor is located. Make sure the ground wires are making a good connection to the metal eyelet to which the ground wires are connected. You may have to cut the wires and solder them to a new metal eyelet then rebolt the metal eyelet back to the motor.

I had this issue with my S14 years ago. Turns out the ground wires shorted out where they connected to the metal eyelet. After cutting the wires and soldering them to a new metal eyelet & bolting it to the engine, the problem was fixed.

Hope this helps....

ID