I'm offering $100 to anyone who can solve my car's nightmarish issues

[KnifeySpoony]

2 hours ago, KnifeySpoony said:

What the OP is describing is simply loss of power. When he declutches, the engine just idles normally. Nothing is "restarting". Am I wrong?

 

2 hours ago, Ted7 said:

You are. The engine is shutting off, as if I was turning off the engine with the key.  It is completely dead and restarts at idling speed when I depress the clutch.

 

15 minutes ago, Vovchandr said:

I thing I got the gist. 

 

Everything is fine then engine stops responding to throttle and rpm reads zero. Car starts engine braking. 

 

He pushes the clutch in, tach shows idle and RPM idles happily like nothing ever happen. Continue blatting as normal. 

12 minutes ago, Ted7 said:

 

This ^ 

I don't get it. That is literally what I described earlier and you said I was wrong...

 

 

Edited July 29 by KnifeySpoony

[Ted7]

2 minutes ago, KnifeySpoony said:

 

 

I don't get it. That is literally what I described earlier and you said I was wrong...

 

 

 

My bad, I'm working on my second screen at the same time and I must have slipped...

[IamScotticus]

You're not trolling.  This is not trolling. 

I sent you my phone # to your mail, I'd like to talk about this and tell you what my master mechanic brother suggested. 

[Davemk1]

The engine is not running, the clutch pedal is pushed in, the engine starts running and the starter motor never turns?

 

dave

[Vovchandr]

2 minutes ago, Davemk1 said:

The engine is not running, the clutch pedal is pushed in, the engine starts running and the starter motor never turns?

 

dave

 

Without waiting for OP. Correct. While in motion once the engine cuts out. 

 

We are still pending a test of putting car into neutral instead of clutch while in motion after cut out and we are pending coming to compete stop after cutout and testing start/clutch. 

Edited July 31 by Vovchandr

[wdb]

(On vacation but checking in, glad to see some progress.) So, the car is driving along just fine then the engine dies with the tach going to zero. That's electrical. Pressing the clutch pedal causes electrical reconnection to occur and the engine refires.

 

If there is no switch or sensor of any type related to the clutch pedal and/or mechanism, what is causing the clutch pedal to have an impact on the electrical system? Either there is a switch and it has not been located, or the act of disengaging the physical parts of the clutch assembly is making/breaking what I'll call an "unintended" electrical circuit. I have a really hard time getting the latter to make sense. I suppose a loose or pinched wire in the pedal vicinity could be involved but that should be fairly easy to see.

 

An outside possibility could be engine/transmission grounding. That could be tested with some grounding straps bolted to appropriate stuff at each end. If they're already in place, check that they are making good electrical contact, i.e. bare metal to bare metal. I once helped a friend diagnose why the throttle cable housing on his MGB kept melting; turned out that the only thing grounding the engine to the chassis was the cable! Lots of amps going through that skinny little wire. 

[panamericano]

Hunch.  It has little to do with the clutch it's self.  Something, like a crankshaft position sensor is getting out of line.  Wobbling, or loose?  The engine goes from power torque to braking torque and that still keeps the problem piece off its spot.  The clutch eliminates any torque shaking for a moment so, instant restart.  Something like that.  

[Vovchandr]

9 minutes ago, panamericano said:

Hunch.  It has little to do with the clutch it's self.  Something, like a crankshaft position sensor is getting out of line.  Wobbling, or loose?  The engine goes from power torque to braking torque and that still keeps the problem piece off its spot.  The clutch eliminates any torque shaking for a moment so, instant restart.  Something like that.  

 

I agree with that theory which is why I suggest putting it into neutral next time it happens without touching the clutch to partition. 

[Ted7]

Had a conversation with Scotticus  2 days ago and I think he got it right.  The culprit seems to be, that goddamn fuel pump 

 

I drove it yesterday in "quiet mode" on the freeway, all was working fine but 10 minutes after cruising at 65-70mph, it happened again. Car slows down, depressing clutch, engine restarts.

 

Drove it this morning in "warrior mode" on the freeway, after a few miles (like 8-10 miles) it started acting again, but way  way more, like 3 or 4 times in a row.  Slowed down as I was exiting the freeway, no more cut offs. 

 

I'll have the fuel pump removed this weekend and try to find a replacement asap.  Hopefully I'll be able to make it to Monterey Car Week mid August.

 

To be continued... 

 

[Ted7]

4 hours ago, panamericano said:

Hunch.  It has little to do with the clutch it's self.  Something, like a crankshaft position sensor is getting out of line.  Wobbling, or loose?  The engine goes from power torque to braking torque and that still keeps the problem piece off its spot.  The clutch eliminates any torque shaking for a moment so, instant restart.  Something like that.  

It has been replaced, it wasn't that 

[Ted7]

5 hours ago, Vovchandr said:

 

Without waiting for OP. Correct. While in motion once the engine cuts out. 

 

We are still pending a test of putting car into neutral instead of clutch while in motion after cut out and we are pending coming to compete stop after cutout and testing start/clutch. 

It always happens on the freeway, impossible to pull over, but check my previous post

[Vovchandr]

12 minutes ago, Ted7 said:

It always happens on the freeway, impossible to pull over, but check my previous post

 

I see your post im not just not sure about this point. Are your freeways different than mine? I've broken down multiple times and pull over to a side as my car didn't restart and I didn't have a choice. Both full electrical cut off. Once alternator died and other time I lost battery terminal. In second picture I had to push it back uphill to get to the exit that I passed. 

 

Also you don't need to be pulling over to try to put it into neutral for a second before trying the clutch

 

If you put it into neutral and it comes back to life then it's a quick way to eliminate the clutch. 

 

Fuel pump doesn't explain your tach dying and going 0 rpm  while still in gear and rolling 

 

 

 

Edited July 31 by Vovchandr

[Ted7]

8 minutes ago, Vovchandr said:

 

Are your freeways different than mine? I've broken down multiple times and pull over to a side as my car didn't restart and I didn't have a choice.

 

 

California Highway, 5 lanes to cross to get to the shoulder... I'm not taking the risk with a miniature car slowing down in the middle of the traffic... Someone already clipped my rear wing because "he couldn't see me"...

 

[Vovchandr]

38 minutes ago, Ted7 said:

 

California Highway, 5 lanes to cross to get to the shoulder... I'm not taking the risk with a miniature car slowing down in the middle of the traffic... Someone already clipped my rear wing because "he couldn't see me"...

 

 

If this is a problem that only happens on busy 5 lane highways with you being in the fast far left lane I have a very easy solution to your problem. 

 

Otherwise at the very least let me know what it does once you put it into neutral before you hit the clutch. I'm sure a 3 second delay won't kill you. 

Edited July 31 by Vovchandr

[Vovchandr]

You're also commiting to ripping out a fuel pump without a replacement or verifying that it's bad? Seems strange.

 

Why not get an electric fuel pressure gauge and quickly mock it up? If the fuel pressure goes to 0 when this happens then yeah it's likely a pump. If the fuel pressure remains steady at 40 then I wouldn't be so quick to commit to a pump change. 

 

Either way fuel pump still has no relevance to your rpms dropping to 0/tach dying unless you're describing that wrong. 

 

Can you provide a report of what troubleshooting/testing/partitioning been done since this thread started?

 

Do you have those engine bay pictures?

[Ted7]

4 hours ago, Vovchandr said:

You're also commiting to ripping out a fuel pump without a replacement or verifying that it's bad? Seems strange.

 

Why not get an electric fuel pressure gauge and quickly mock it up? If the fuel pressure goes to 0 when this happens then yeah it's likely a pump. If the fuel pressure remains steady at 40 then I wouldn't be so quick to commit to a pump change. 

 

Either way fuel pump still has no relevance to your rpms dropping to 0/tach dying unless you're describing that wrong. 

 

Can you provide a report of what troubleshooting/testing/partitioning been done since this thread started?

 

Do you have those engine bay pictures?

 

[IamScotticus]

I agree with the idea of mocking up a mechanical pressure guage to watch fuel pressure.  We need to know what the pressure is required at the moments of fuel demand he is cutting out.

Part of my brother's theory is that if he is getting starvation,  the engine will cut ignition rather than run lean.  This could happen too subtly to observe on a guage while driving.  The alternative to this is read the 02 sensor codes for lean signals.  If Ted can, it could confirm which rabbit hole to go down.  One thing is true,  the fuel pump is going on 20 years, the cutting out was an issue before Ted rebuilt the engine, and the pump is the constant before and after the rebuild.  We all know fuel pumps can fail sporadically.  I replaced the ignition on my 02 Ford Ranger, not thinking it could be the pump.  It was the pump. 

Sure, there are many things we can't explain,  but a computer is running this car.

Heck,  is the Caterham fuel pump capable of feeding an SVT adequately? 

Edited August 1 by IamScotticus

[Vovchandr]

I don't think these symptoms match the problem and resolution described but I'll gladly be proven wrong if he goes down this path and resolves the issue. 

 

I went for probably 5 years with my cutting out issues and only recently mostly resolved it down to being a poor fuel map issue on the ECU. 

 

One of the most critical points to an intermittent issue troubleshooting is being able to recreate the fault conditions on demand and proceed with partitioning from then on. 

 

 

[wdb]

8 hours ago, IamScotticus said:

 

Part of my brother's theory is that if he is getting starvation,  the engine will cut ignition rather than run lean.  This could happen too subtly to observe on a guage while driving.  The alternative to this is read the 02 sensor codes for lean signals.  If Ted can, it could confirm which rabbit hole to go down. 

 

 

 

I've never heard of an ECU that would cut power to an engine due to lean condition. It sounds extremely dangerous! But I am far from an expert on modern engine control systems. 

 

An OBD reader might be very illuminating. Do modern Caterhams have that capability?

[mrmustang]

Just throwing this out there:

Faulty or failing inertia switch (vibration will cause it to not trip 100%, but cause the sudden loss of electrical power to the fuel pump). No real way to test it though, cheap enough to replace.

 

Perhaps stay out of the far left lane and stick to the right lane until you figure out what the issue is.