Hey guys. Dealing with a ‘94 manual Disco. I am having continual issues with my disco having big fuel loss while driving and a randomly jumpy idle. Fuel pump is brand new (PO supposedly replaced), fuel filter is brand new. I was actually having a no start issue even after getting 12 volts to the multi port fuel pump connector, but after cleaning the relevant connectors and adding dialectic, C434 and C407, she fired up. C434 is a bit fried though. When you start driving power loss is almost immediate and the gas pedal becomes unresponsive unless you toss it in neutral, give it a ton of gas, and the put it back into gear.





Ive basically decided that it’s a bad ground or at least that’s the next thing to check. In the Electrical troubleshooting manual it shows E404 as the ground. However it doesn’t give a description of where it is. The listing of grounds stops at E402. Any ideas where to look? I will clean up E400 since that is listed.

 

Now I’m thinking it’s the connector itself since it’s so burnt out. I’m going to try and order another one (special order from AB) and if they can’t get me one, I’ll splice it up by hand and try and wait for a D1 part out. The connector on the fuel pump housing is also burnt out. I am going to try and get away with just cleaning that as I don’t want to shell out $150 for a whole new housing.

My fuel pump relay failed the bench test. No resistance at all between the 86 and 85 pin. The truck still starts so I’m not sure how this is affecting the fuel system, but I suspect it had something to do with that connector getting roasted.

 

That looks like a non AEL fuel pump, and you can get the entire thing for 50.00 online.

 

Being a 1994, it wouldn't have AEL.

I'll add the recommendation to chase the fuel pump harness back under the truck to the area rearward of the driver's side rear tire. The harness can deteriorate in this section creating a headache. I know this from experience.

 

The same very thing happened to me. The truck would start right up, I'd drive off and sometimes at a traffic light it would cut off and require several attempts to restart. It got so bad that now I would have to get out of the truck and wiggle the wires connected to the pump. Replacing the wiring harness solved the problem.

The burn mark on the plug head is a sign of compromised wire. Dielectric grease helped for awhile till it didn't.

 

For those that have a similar issue and find this in a search. Toran was right which is what I assumed it was too. I replaced the fuel pump relay and I replaced the melted pin after I cut the burnt part of the wire off. It runs like a top now.

 

Glad your up and running again.