Electrical Hesitation - mostly in 2nd and 3rd gear

[LostinDartmouth]

Hello Folks. Strange problem just cropped up in the 85 BJ70 420,000 kms. When driving along, there is an intermittent loss of electrical power along with a relay sound clicking very quickly near the passenger right foot area. It almost sounds like a pack of cards being shuffled (perhaps a relay freaking out?). It is intermittent and seems to be worse when trying to accelerate or perhaps under load. It almost feels like the ignition relay is shorting out. Didn't seem to happen when the weather was cold for the past few months. Now the weather is warm and the problem now persists. Also, just replaced both batteries and cleaned up some grounds in the engine bay this morning before the electrical problem started. Perhaps I hit something or jostled something loose in the bay? The 70 idles and starts just fine. Anyone have some genius ideas?? Before I start pulling the dash.

 

[LostinDartmouth]

Further, info. There are two relay boxes in the location: fuel relay box that isn't mounted to anything and another smaller grey relay beside it.
Photos may help....

 

[LostinDartmouth]

and this one.

 

[duncanrm]

This is a common problem with 2Hs, your engine and fuel control system share the the same heritage.

Your disturbed earths are very likely to blame. I wrote a small FAQ about it here:

2H - Engine loses briefly power every 10 seconds or so - https://docs.google.com/document/d/1QLOZmfRmmCzph8fZyzs3CgSOZ1VlmX11gMyKRNILOKU

From that FAQ:

"This is a common problem with 2Hs. The EDIC is cycling to STOP briefly. Its usually poor engine or body earths and it usually happens more when there's a heavier electrical load on the alternator (e.g. headlights on). To fix it, remake all your earth points (new terminals, wire wheel on the attachment points, new cables if necessary).. mostly this solves the issue. In the meantime you can pop the EDIC rod off and it'll stop the problem, but you'll have to stall the vehicle to stop it. If this doesn't resolve it then you may have a faulty EDIC motor or fuel control relay. Some people have reported success with cleaning up contacts in the EDIC Motor and others have opened up the Fuel Control Relay and resolved PCB issues. If nothing else resolves it, a simple, possibly long term solution, is to leave the EDIC rod off and to fit a "stop cable", not ideal, but it works."

 

[LostinDartmouth]

Thanks Duncanrm. Much appreciated. Just came back from another test drive. It is definitely the fuel relay that is cycling on and off under load.
The earth grounds make sense to me. This problem didn't exist until I replaced both batteries, cleaned up the terminals, and tried cleaning up some body grounds. I suspect i may have made something worse under the hood when doing so. Will start by rechecking my grounds.

 

[LostinDartmouth]

Just checking my assumptions: From what i can tell from searching similar threads, the grounding of the EDIC motor is done through the Fuel Control Relay box. Battery grounds are also suspected points.

Are there other ground points that you have found are the problem?

 

[duncanrm]

Just checking my assumptions: From what i can tell from searching similar threads, the grounding of the EDIC motor is done through the Fuel Control Relay box. Battery grounds are also suspected points.

Most of the vehicles that experience this problem are 30+ years old. So how the engine and body etc are grounded can be anyone's guess after years of repairs, mods and improvements. I often just rework the earths completely and don't bother too much with factory wiring or keeping it original. A good fat cable to the engine with excellent crimped terminals and a not so fat one to the body making sure that if the body has two halves (like a 40 series troopy) that the top half is also adequately earthed, a check of the steering column rag joint to see if there's an earth jumper over that and remaking it also a worthwhile check.

I can't confirm your assumption that the EDIC motor is grounded through the FCR.

 

[LostinDartmouth]

Nice work, Ducanrm. I think you nailed it. We rewired and relocated the battery grounds, remounted the Fuel Pump Relay, and cleaned up other body grounds in the engine bay. Used sandpaper and brake cleaner. Went for a 1/2 hour drive, headlights on, fan blower on: no hesitation, no speed clicking from the pump relay. Will take it for a longer drive tomorrow to confirm, but wanted to say "thanks" for the quick and helpful response.
Don't like the state of the current engine ground so will purchase a proper braided ground later in the week.

 

[duncanrm]

but wanted to say "thanks" for the quick and helpful response.
Don't like the state of the current engine ground so will purchase a proper braided ground later in the week.

Nice, I'm glad it appears to have resolved. Fingers crossed it stays fixed.

 

[LostinDartmouth]

A quick update. Went for a full hour drive. Headlight lights on, blower fan on med, hard acceleration, etc. There was no hesitation nor fuel relay clicking.
Nice to solve the problem in 24 hours......

Now if I could just get some frig'n heat in the cab.....