Car suddenly cuts out during highway cruising

[lethanh93]

I tried searching google and zilvia but haven't been able to figure out the issue.
Recently my ka24e 5 speed(s13) suddenly loses power and starts decelerating when I'm cruising on the highway. Quickly putting the clutch in and out temporarily gets rid of the problem but I'd like to fix it.
The problem is really random, it sometimes happens 3 times in a row or it might not happen for 200 miles of cruising. Might be coincidence but it hasn't happened while in any of the other gears, only 5th while on the highway.

Recent things that I've done on the car/ relevant? info:
-5 lug conversion all the way around, torqued everything to spec, used some junkyard z32 hubs for rear and aftermarket for the front. There isn't any play and all wheels spin freely off the ground.
-q45 front brakes
-wheels and tires
-speed sensor works intermittently but the gears look fine when I pulled them.

Any help would be appreciated.

[Jamaica]

Replace VSS

[lethanh93]

I've tried another vss and I had the same issues. I think my speedo problem is due to wiring but haven't had time to check.
Would a bad vss really cause the car to bog down at highway speeds?

[bboyclo]

could be your fuel pump, had a car that was doing that before

[lethanh93]

Is there a way to test that? Thought it might have been drive train since declutching and clutching fixes it.

[Kingtal0n]

fuel pump with a .01% chance its the eccs relay because somebody wired an alarm in wrong

the clutch gives it away. you jar the drivetrain, vibration frees the pump. In theory.

[angel mkiv]

Is your car lowered? Could be the chassis harness rubbing on your tires under the fenders

[Rustys14]

Its your fuel pump. Same thing happened to me and the car was good to go as soon as I replaced the pump. Just chuck a walbro 255 in there so you have room for future upgrades and call it a day.

I did have a eccs relay problem in a separate chassis that caused similar problems (car would die when turning left) but as kingtal0n said its unlikely that's your issue since there are usually other electrical gremlins that go with it.

[Kingtal0n]

Originally Posted by Rustys14

Its your fuel pump. Same thing happened to me and the car was good to go as soon as I replaced the pump. Just chuck a walbro 255 in there so you have room for future upgrades and call it a day.

I did have a eccs relay problem in a separate chassis that caused similar problems (car would die when turning left) but as kingtal0n said its unlikely that's your issue since there are usually other electrical gremlins that go with it.

right, it should go without saying (but lets be clear) that if the engine goes into decell but ALL the electronics stay active (your radio, cluster, windows still work, etc...) then you are sure the ignition switch isn't the source or related. However, since the eccs ties to the ECU it is possible however unlikely that the power can be removed from the ECU while all other electronics stay active.

[lethanh93]

I have wired an alarm but I soldered and heatshrinked all connections.
Car is lowered, I just put some wider rubber so maybe could be a cause, I'll check when it's not pouring lol.
Fuel pump seems to be the consensus. Thought it was fuel cut at first too but some tranny fluid came out when I swapped speed sensors and I was worried it could be my tranny.
Thanks for the help. I'll let you know how it goes once I get my hands on one.

[Kingtal0n]

Updates? Wazitdatfuelpump?

[!Zar!]

How fast are you driving?

If you go over 110mph, the speed governor kicks in and slows your car down.

[lethanh93]

Sorry haven't been able to address the issue yet. Will probably have a solid update by next week.

Also, its generally lower speeds. At like 85 and had it happen at 70 once

[dbeiler]

Originally Posted by !Zar!

How fast are you driving?

If you go over 110mph, the speed governor kicks in and slows your car down.

^What he said.
Does it feel like the governor is cutting power? We all know what that speed governor feels like, right?! Considering you're having the issue in fifth gear only, and your speedo is working intermittently, this is a likely culprit. When the car dies, does it happen as the speedo needle drops down or goes to high limit?

The speed sensor signal runs from trans speed sensor > gauge cluster > ECU.
A poopy cluster can distort the speed signal; the ECU reads the signal as over limit and cuts fuel.

[lethanh93]

I've never felt what the speed governer feels like unless its what's happening now. When the car slows, it just becomes unresponsive to throttle and starts engine braking. I get around it either by quickly double clutching or wait it out for about 5 seconds. Happens seemingly randomly but almost always on the highway.
When my speedo is dead, its completely dead with the needle at 0 and not moving. I just tested my speed sensor so Im pretty sure its the cluster.
I'm replacing the cluster tomorrow and I'll probably grab a fuel pump in case. If it still happens without a new pump could chalk it up to the cluster.

Thanks for the help.

[lethanh93]

Alright. I was going to try and buy the things from mogli while I was in socal during break but he didn't respond to me. :/ I'll try sourcing the parts when I get back to school and I'll update then.

[lethanh93]

Small update. On my drive back to school, I still had the issue when my speedo wasn't working during the first ~150 miles. During the last ~250 miles, the speedo decided to work and the issue never came up.

Thinking its probably the cluster in this case.