Disco 2 / Cranks but won't start

[Explorer0863]

My Disco 2 is a 99 with the 4.0 Bosch engine; 175,000 miles.

I went to the post office the other day and after getting my mail the Disco didn't start. It would turn over but didn't start. Ended up calling AAA and towed it home. I checked spark, fuel, engine codes, inertia switch. All good. About 3-4 hours later I tried again and it was perfectly normal and ran fine for a few days.

A couple of days later my wife took the Disco and on her way to work she stopped for breakfast. The same thing happened: it would turn over but didn't start. I picked her up. We left the Disco at the breakfast place and I gave her a ride to work. About 8-9 hrs later, on the way back from work, I decided to go and check the Disco and give it another try. Again, it ran perfectly for a few miles, but it died for good at home.

One of my buddies told me to replace the crank position sensor; which I did. It was replaced with a Bosch sensor. It didn't work. Crank but no start. On my third attempt the muffler exploded. After the explosion, it was late and dark, so I didn't try to start it again until today.

Today I tried again and this time it fired up the 1st time. It was loud without the muffler, but finally the engine was running. After 10 minutes, I turned it off and now is dead again. Cranks but no start.

I've been thinking about an intermittent issue with the fuel pump or perhaps the coil packs? Any ideas or suggestions? What should I check next?

Thanks!

Tony

 

[ozscott]

Could be fuel pump so test pressure at the valve at back of intake manifold (driver's side for you...passenger side for me). Also I have had the same problem where I first replaced CPS and same as you didnt work. I had no start at all however. I replaced fuel pump - no change. I had to replace the underdash unit complete - ie fuse box with IDU inside. Must have had a crack because it was, after syncing with ECU, then completely fine and no further problems...pain the arse.

Many years ago I had problems interfering with the security system and it would spin over but no start outside certain Chemists however yours is having the problem at too many different places for that to be the problem.

Cheers

 

[Rob371]

I'm no expert on the quirks of the rovers. I bought one in November so I am learning the nuances. I had to replace crank sensor in first week. It was fine for a few days then it stalled, would not restart. A bit later it would start, then I would shut it off and would not start. This went on for a couple days and I replaced crank sensor. Never had a check engine light, no codes. No issues since replaced.

The basics,... spark, fuel, compression. Does it have spark during cranking? If you blew out exhaust then it probably had fuel pressure and a crank signal to deliver fuel to the exhaust. It was firing injectors so you you had a crank signal, otherwise injectors won't fire. Could have a leaky injector so that's possibly another problem on top of the no start. At some point it had spark igniting the residual fuel in exhaust. Without a crank signal there will be no injectors firing and no spark. When my crank sensor intermittently failed and restarted it never ran rich at start up which tells me the injectors were not firing when it failed and I kept on cranking. So basically no crank signal means no spark and no injectors firing so there should be no fuel in the exhaust to ignite. If it has weak fuel pressure it's just going to cough and die or barely idle, or won't accelerate depending on how much fuel pressure you have.

 

[discostew]

You say you had spark while it wasn't starting. You said you checked the fuel psi also right? I would keep checking those and maybe make sure you have spark from both coil packs when it acts up.

Might also want to look at the connectors on the ECM. I've seen a couple of those ECMs have some kind of thermal event and melt some of those connectors. It was pretty intermittent like what you have going on. Also going to wan't to make sure your injectors are getting the battery voltage on one terminal and a pulsing ground on the other when its acting up.

 

[Explorer0863]

Could be fuel pump so test pressure at the valve at back of intake manifold (driver's side for you...passenger side for me). Also I have had the same problem where I first replaced CPS and same as you didnt work. I had no start at all however. I replaced fuel pump - no change. I had to replace the underdash unit complete - ie fuse box with IDU inside. Must have had a crack because it was, after syncing with ECU, then completely fine and no further problems...pain the arse.

Many years ago I had problems interfering with the security system and it would spin over but no start outside certain Chemists however yours is having the problem at too many different places for that to be the problem.

Cheers

I will check the pressure this week. Need to get a gauge. I know there is fuel entering the engine because I can hear the pump running, there is a strong smell of gasoline, when cranking it backfires like crazy; not to mention the explosion of the muffler. I believe the correct pressure should 50, correct?

 

[Explorer0863]

I'm no expert on the quirks of the rovers. I bought one in November so I am learning the nuances. I had to replace crank sensor in first week. It was fine for a few days then it stalled, would not restart. A bit later it would start, then I would shut it off and would not start. This went on for a couple days and I replaced crank sensor. Never had a check engine light, no codes. No issues since replaced.

The basics,... spark, fuel, compression. Does it have spark during cranking? If you blew out exhaust then it probably had fuel pressure and a crank signal to deliver fuel to the exhaust. It was firing injectors so you you had a crank signal, otherwise injectors won't fire. Could have a leaky injector so that's possibly another problem on top of the no start. At some point it had spark igniting the residual fuel in exhaust. Without a crank signal there will be no injectors firing and no spark. When my crank sensor intermittently failed and restarted it never ran rich at start up which tells me the injectors were not firing when it failed and I kept on cranking. So basically no crank signal means no spark and no injectors firing so there should be no fuel in the exhaust to ignite. If it has weak fuel pressure it's just going to cough and die or barely idle, or won't accelerate depending on how much fuel pressure you have.

I have spark and fuel; and I have spark during cranking.

 

[Explorer0863]

You say you had spark while it wasn't starting. You said you checked the fuel psi also right? I would keep checking those and maybe make sure you have spark from both coil packs when it acts up.

Might also want to look at the connectors on the ECM. I've seen a couple of those ECMs have some kind of thermal event and melt some of those connectors. It was pretty intermittent like what you have going on. Also going to wan't to make sure your injectors are getting the battery voltage on one terminal and a pulsing ground on the other when its acting up.

No, I haven't checked the fuel PSI yet. Need to get a gauge. I believe that it is located behind the IM, on the left side of the engine, sandwiched between the IM and the firewall. I think is the plug with the green plastic cap, correct?

Is the ECM located near the footwell, right side of the Disco 2?

Need to check how to make sure the injectors are getting the correct voltage. I have the RAVE manual, so It should be somewhere in there.

 

[Rob371]

Is the converter in tact? Could be plugged. Too much back pressure will cause a no start and could lead to excess fuel in the exhaust and possibly resulting in blowing the muffler out.

 

[edthediscoman]

The fuel rail has a schrader valve on it. Its on the passenger side (USA) next to the intake manifold further forward on most (Not near the firewall). You can use a tire gauge on it. Carefully of course...

 

[Rob371]

Weird. The schrader valve on mine is at the back of the fuel rail below the intake against the firewall. It's a nightmare.

 

[discostew]

Weird. The schrader valve on mine is at the back of the fuel rail below the intake against the firewall. It's a nightmare.

That's the one. Disco1 is on the side easy to get at.

 

[discostew]

Is the converter in tact? Could be plugged. Too much back pressure will cause a no start and could lead to excess fuel in the exhaust and possibly resulting in blowing the muffler out.

But the pressure would have been up in front of the converters.

I bet the muffler blew up cause of raw fuel in the exhaust. Makes me think it's spark your loosing.

 

[Rob371]

But the pressure would have been up in front of the converters.

I'm not saying the back pressure caused the blowout, it's the fuel vapors in the exhaust that did that.

If the converter is plugged it will not start because of back pressure. It will still spark, it will still fire injectors. the plugs will become fuel fouled, fuel continues to fill the exhaust with continued cranking, and if circumstances are right the fuel vapors in the exhaust ignites, blowing out the muffler.

You can remove the O2 sensor ahead of the converter and adapt a cheap fuel pressure gauge, crank the engine and a good system should be maybe 1.5 to 2 psi.

 

[Explorer0863]

I managed to get a fuel pressure gauge, but the location of the valve is pretty impossible to reach, at least for my hands.

The catalytic converters were deleted by a previous owner. It's on my list of things to do. That eliminates the pressure build up at the converters.

When I crank, it continues to backfire like crazy. A friend of mine is suspecting the fuel pump and he suggested to spray starter fluid to the throttle body. I'm not 100% sure that I want to do that due to the muffler explosion. Read somewhere that it can explode the IM. What do you guys think?

 

[JohnB]

When I had a no start issue I sprayed with starting fluid via one of the fittings on the intake manifold. It started and ran enough for me to understand it was a fuel related issue. You can also pull the fuel pump relay and hot wire the plug so you can verify if the pump is working by listening at the fuel tank. If the engine does not start after about 30 seconds of cranking the BCU turns off the fuel pump relay.

I replaced my pump with an aftermarket unit but that was a pain since the fuel fittings are plastic and need to be replaced and are a pain to slip on. Think you need to heat them up which with fuel and crap around aren't something that is easy or safe to do. Pump was like $25 on ebay.

I kinda doubt your issue is fuel since you had enough gas in your exhaust to blow it up which means your injectors are working. DME never has issues on D2's.
You should probably verify spark with an old spark plug. The inside fuse box is a known no start issue and that supplies power to your coils. I found a used one at a local yard but it wasn't my problem.

 

[Explorer0863]

The inside fuse box is a known no start issue and that supplies power to your coils.

Interesting. About 6 months ago I had the "fuse to blower motor" electrical issue and I replaced the inside fuse box with a used one from a junk yard. The A/C came back to life and everything has been working fine, but your statement above got me thinking about it. What else can you tell me about that?

 

[Explorer0863]

I managed to connect the fuel pressure gauge today. I got 0 psi, but when I removed the gauge, the connector was wet (gasoline). Weird.

Removed the rear seats, carpet and fuel pump cover. I can't hear the pump running. I have the fuel pump with the extra black connector for the pressure sensor. My multimeter is not showing any voltage when I turn my ignition switch to the 2nd position.

I checked fuse #10 and it's good. Pulled the relay (R1), tested it and it's good as well.

Removed the inertia switch. Removed the rubber cover and inspected it. Don't know how to test it. It looks "normal". Is there any way to test this switch?

The other part that may cause the fuel pump to stop is the crank position sensor, which is new. The backfires continue and very loud. I'm about to throw the towel. Any suggestions?

 

[squirt]

If you power the fuel pump directly (jumpers from battery voltage), what is the result? Based on the path you're following, this should allow the vehicle to run normally. Have your fuel pressure gauge installed while doing this to confirm that you're getting good pressure while the pump is running. (both to confirm that it's a signaling problem vs inefficient pump AND to confirm that you're using the FP gauge correctly)

Are you getting power INPUT at the fuse and/or relay? Is the relay clicking when you turn on the key? It sounds like you're checking components, but not confirming current flow. If they're not getting any input, you need to follow the wiring diagram further upstream. If they are getting appropriate voltage a the right times, you need to work downstream.

Based on what I'm reading, this is now a persistent problem, and not the intermittent issue that it was in the beginning, right?

 

[Explorer0863]

If you power the fuel pump directly (jumpers from battery voltage), what is the result? Based on the path you're following, this should allow the vehicle to run normally. Have your fuel pressure gauge installed while doing this to confirm that you're getting good pressure while the pump is running. (both to confirm that it's a signaling problem vs inefficient pump AND to confirm that you're using the FP gauge correctly)

Are you getting power INPUT at the fuse and/or relay? Is the relay clicking when you turn on the key? It sounds like you're checking components, but not confirming current flow. If they're not getting any input, you need to follow the wiring diagram further upstream. If they are getting appropriate voltage a the right times, you need to work downstream.

Based on what I'm reading, this is now a persistent problem, and not the intermittent issue that it was in the beginning, right?

I didn't try to power the fuel pump directly. Not sure how to do that. I'm assuming that I have to remove the plug, identify the pos and neg pin on the pump and apply power to it?

Power input at the fuse and relay: i checked voltage on both ends of the fuse. I removed the relay, tested it on the bench and it clicks. In other words, I don't think that I checked if I'm getting power input. Will do.

Correct, now is persistent. Every time I check or do something to it, I try to start the engine. It's still doing the same thing: cranks, no start and backfiring very, very load.

I'm on my way to the mountains for a weekend camping trip. I'll be working on this late Sunday or Monday and report back as soon as I can.

 

[JohnB]

Interesting. About 6 months ago I had the "fuse to blower motor" electrical issue and I replaced the inside fuse box with a used one from a junk yard. The A/C came back to life and everything has been working fine, but your statement above got me thinking about it. What else can you tell me about that?

It can actually limit the power to your coils. Have you inspected the fuses.

One thing that seems weird to me is your continued backfire. At this point it seems you may have slipped your timing chain or a stuck or broken valve.

As far as no volts back at your pump if you are hearing it you are testing it wrong(must have power). You can pull the relay and run a jumper wire. DME times the relay out after 30 seconds of cranking without starting.

Its always basic with engines fuel,spark,air.
Get a real tester on the shrader valve jump the relay
Pull a wire and test for spark.

If you have both you are into a bigger issue