Hey all! I'm back for help again. A few of you that have been around for some time will be familiar with this Disco and my years of fighting it.

It's been over a year since I've really touched it much, so I figured now was as good a time as any to try again with mother's day.... Three days away.... Anyway....

I did fiddle with it some a couple of months ago. Found if I got my hand in and wiggled the coils around sometimes it would start and run perfectly! I figured that the coils were not getting grounded, so I popped the intake manifold today and actually bolted the mounting plate down.

The truck is back together now. It will start on brake clean, but still will not start on its own. I have bypassed the inertia switch. Hotwired the fuel pump. I know it is running. The truck now will not stay running on its own. Once the brake clean I spray in the intake is used up, it dies.

I have checked all relays, and all fuses. My thought now is that the injectors are not firing. I had it running great a few months ago, intermittently, but now the fuel pump is not running unless hot wired.

I have changed the ECU / BCU / instrument cluster, but that was probably 4 years ago. No change at that time.

The weirdest part is that A couple years ago it actually started running great. She daily drove it for probably 3 months with zero issues, and then this started again. The problem has to be electrical in nature, but I have been all over this truck. Once again I am at a loss. Any insight is very appreciated.

 

Have you done a fuel pressure test? might be really really low??? I had one at 25 psi, really hard starting, but once it fired up it ran great.

 

I have not done a proper pressure test, but I did open the tank and it is making enough pressure to trigger the bypass. Early in my diagnosis a few years ago I also tried a pump out of one of my other discos.

 

And actually, it currently will light off for roughly two seconds and then die again. Let it set a few minutes, same story again. I believe this is the injectors leaking down a little bit and then the truck firing just with what has pooled in the intake runners.

 

How's the gas? A year old with no stabilizer = dead gas and varnish. I make most of my money off of today's poor quality fuels

 

Gas is good. Smells fine, burns fine, no varnish (much to my surprise). With the price of fuels, if I can't get this thing running it's gonna get siphoned and put right in my disco...

 

I'd definitely get a fuel pressure tester and verify that you are getting the right pressure. If one of the injectors is jammed open, that can cause your fuel pressure to drop.

 

That would only be the case if it were not triggering the pressure regulator in the pump. Since it is bypassing I know I'm getting a minimum 47 or 48 psi.

I am concerned that the pump still is not running without being hotwired, even for just a second while the key comes on.

I did swap the ECU/BCU/Cluster back to the original set. No real change.

I went back thru all of the fuses and relays, all still good.

I'm thinking at this point it's time to look toward the fuse boxes. Wishing my parts trucks weren't an hour and a half away. Anyway...

 

Sounds like it fires with the key in the start position, but dies in the run position?? If that’s so, then look for power with the key in the run position down the line. ??? The fuel pump doesn’t run unless the engine is turning over, needs an oil pressure signal. Idk. Couple more ideas

 

Similar to the problem I'm fighting. My research has found that the relay/fuse/IDM inside can cause a no spark condtion, so I had the idea to take it out and see if there were cold, cracked or blown out solder joints. Well, forget that idea. There are 2 boards sandwiched together by 11,257 pins all around the edge like a cage, and getting them unsoldered looked like more work than I was going to bother with.

So, while I'm here-Rave shows the ECU under the right side kick panel, but it is also showing it on a RH drive vehicle. Is it still on the right side on our NA trucks or is it over on the left? I want to check for CKP signal at the ECU before bothering with any other checks.