| Author | Message | ||
     Dave (Discoverover) New Member Username: Discoverover Post Number: 33 Registered: 11-2002 |
Is the flywheel speed sensor mounted differently on 5 speed blocks? Are the 96' and 97' GEMS 5 speed blocks different or modified compared to automatics, at the transmission junction? | ||
| Dave (Discoverover) New Member Username: Discoverover Post Number: 34 Registered: 11-2002 |
Has anybody replaced the engine on their 5 speed discovery? The flywheel sensor is not working right. The GEMS system uses the flywheel for timing because there is no distributor. | ||
| Ron Brown (Ron) Senior Member Username: Ron Post Number: 299 Registered: 04-2001 |
Disco II blocks and disco I blocks have a different crank sensor mounting. AFAIK the 5 speed and autos are the same block (I can check for sure on Monday for other differences, flywheel I am sure), if you are putting in a disco II block you need to take the crank sensor plate off your old block and weld it onto your new block. Ron | ||
| Dave (Discoverover) New Member Username: Discoverover Post Number: 35 Registered: 11-2002 |
Thanks Ron, the funny thing is that it is a new genuine LR disco I block and the crank sensor is giving an off reading on the LR diagnostic computer. The reason that we are checking the flywheel is because of a misfire, and everything else is newly rebuilt. They have never seen this problem before, but then again not too many GEMS 5 speeds have had new blocks put in either. GEMS 5 speeds are kind of rare. Dave | ||
| Ron Brown (Ron) Senior Member Username: Ron Post Number: 305 Registered: 04-2001 |
If you tell me what to look for I will be happy to check on mine (96 5speed) or in the parts book. One thing I have seen is that the crank sensor can be installed wrong and the flywheel hit the sensor bending it causing that fault. Ron shoot me an email to remind me to check tommorrow evilfij (at) yahoo.com | ||
| Dave (Discoverover) New Member Username: Discoverover Post Number: 36 Registered: 11-2002 |
I don't know exactly what to look for. I thought that maybe 5 speeds had a modified mounting plate for the crank sensor. This could explain why my new engine isn't running right, but the crank sensor seems to fit normally. My flywheel turns perfectly with no high spots or wobble, but the sensor is reading like there's a problem. I don't know for sure what is going on, so don't spend too much time checking it out. Thanks, Dave | ||
| J E Robison Service Co (Robisonservice) Member Username: Robisonservice Post Number: 89 Registered: 10-2002 |
I can provide a better explanation of what he's looking for . . . The truck has a new engine, with a misfire at part throttle on #3 cylinder. The block is the same for manual and automatic GEMS engines. The crank sensor and spacer plate are different, having differing engagement depths for the two types of flywheel. There is not supposed to be any adjustment, but the sensor is off-center with respect to the flywheel. Possibly that matters, possibly it doesn't. Presumably it's a machining tolerance at the factory as it goes into a bore in the block. The problem is that the truck has a roughness in cylinder #3, but the vehicle has perfectly even compression, no vacuum leaks, nothing blocking the intake. It's had new injectors fitted on the left side, a new coil pack, and new ignition wiring, all to no effect. We are thinking there may be a problem with the #3 ignition timing, which comes from the crank sensor, but we aren't sure. All parts are genuine LR. We'll talk to our friends in the UK tomorrow, and we will post the answer as soon as we learn it. The Testbook shows the fuel trim lean on the left side, becuase there is unburned fuel from the #3 cylinder, and the whole side adjusts lean to compensate. All other readings are normal. All sensors respond normally. | ||
| Ron Brown (Ron) Senior Member Username: Ron Post Number: 308 Registered: 04-2001 |
The crank sensor issues I have seen effect more than one cylinder. I can't see how the crank sensor would only effect #3 either. what codes did it throw? None? Just a #3 misfire or did you get crank sensor codes (it sometimes comes up tooth count wrong or something like that). To be honest though, I would just be grasping at straws, guessing now. I will ask around on Monday with the extra info. Ron | ||
| Ron Brown (Ron) Senior Member Username: Ron Post Number: 315 Registered: 04-2001 |
The best guess I got was a bent tooth on the reluctor ring. I am about as lost on this one as you are. Let me know how it comes out. Ron | ||
| Dave (Discoverover) New Member Username: Discoverover Post Number: 37 Registered: 11-2002 |
Thanks Ron, I will. Dave | ||
| J E Robison Service Co (Robisonservice) Member Username: Robisonservice Post Number: 91 Registered: 10-2002 |
The "bent tooth" problem is common on automatics where the sheet metal teeth stick out. On a manual, the teeth are embedded in the flywheel and they can't bend. |
