I have just found a 98 D1 at a car lot that wanted $1000 cause they could not get it to run.. I have been looking for a parts car but not at that price. The day before I left for a vacation I pick my 99 D1 from the shop and drove by - saw that they got it running.. here is their story.
Needed a cam sensor cause it gets fouled and goes into limp mode. We had an offer for $1800 if we fixed it so we tried.. still not running right so the crusher is coming today to give us 100 for the wheels and 400 for the body - got 5 on ya?

So I limped it to the local shop and hid it there (wife) till i returned from the trip.

It needed a battery - started and went into closed loop and ran great 1/2 way home. I was thinking I was real lucky.. for half the drive home.

The issue is - idles but will start misfiring and will not go over 1750 in open loop but when i clear codes and get it into closed loop it will not even get past 1200 rpm

THE HINTS -- 1) the tachometer did not work as I limped to the shop. after the battery change - it worked. I did not notice when the tach quit but .. it has not recovered since.. and it has not ran smooth since either.

2) the rear O2 sensors were discoed .. after I re hooked them up the codes are clear except the misfire codes (several including the multiple and cat damage ones)

3) the exhaust has a loud clanging sound as it starts but gets a little quieter as she warms up.. SO i check the timing advance with the ultra gauge and found the timing going from 30 at idle to 17 as i try to raise the RPM's at finding this I disconnected both knock sensors and now the timing is trying to get into the higher 30's but the running or failure to run is the same.

BTW - the alternator is showing a healthy 14.6 volts and I have cleaned the white wire to the tachometer with no change.

I have started it at night and see no sparks around the wires or coils.

I have check fuel pressure and it is healthy - but the regulator was discoed. as I have had it idling long and getting to normal temp, there was no hot restart issue so the regulator should be good.

I put new plugs in - the others were fowled but then cleaned by a brush so I swapped them out. Also ran two bottles of heat into a 1/2 full tank of 91 octane. no change.

I will try cleaning the cam sensor as the lot was describing but that may have been BS as they claimed the sensor was a $480.00 item. There is an old one under the hood by the wipers though .. ??

CLUES anyone? c'mon give me your best shots..

thanks to all who are up for the challenge.

 

My money is on ignition. Or at least the coil not getting the proper signal from the sensor. If it was plugs or wires wouldn't it run poorly all the time? Plugs or wires don't know about open or closed loop.
So it's gotta be something that changes with open or closed loop. Something the computer can change. Like timing (knock cam/crank signals). Temp sensor controls mixture right?. But i guess if it were fuel it would just run like crap. Black smoke or starve for fuel.

Yep I would guess something ignition.

 

Thanks shiftonthefly
I can see that reasoning.

I am not familiar with a way to test the coils, other than remove them from my 99 D1 and I hate to do that yet. But like you say .. a test may not count for what is telling the coils to behave that way. Like limp mode only worse.

I know there is a circuit board behind the tachometer but I can't find evidence that it communicates with the ECU. If it does, then that could be messing up the ignition. It would also explain the way it ran great while I saw the tach working that one short period.

 

This is a total shot in the dark but I had some issues with other late model trucks that had similar issues. I replaced cam and crank sensors (they were easy and cheap) and it still runs great. In that truck tach stopped working too. But i could definitely be totally off. Someone more Rover savvy will chime in soon and give you actual real help. Haha

 

Just gonna throw this in, though not rover but maybe related. On my Volvos the tach not working was the tip that the crank position sensor was caput.

 

I had the thought last night to go pick the brains of the car lot mechanics that lost their shirt on this truck. I even offered them 20 bucks for their time to tell me what all they tried so I would not replicate their efforts.

Sounds like the wiring harness is toast. Or more like turned to butter from the oil leaks. You can see where people have pulled it out and apart looking for signs of damage but they say that was making it run.. for a bit. But was not a fix.

Unless something causes me to get real lucky, this truck is going to a storage hole till I can get all the parts i want off it.

Shame since the body has less rust, two a/c units (that blow cold) working sunroofs, interior lights that work (my mfu is toast) and the transfer case is not frozen like my 99 is. I was really wanting it the be the keeper. Oh yea.. my from breaks are metal on metal now and the 98 has perfect brakes ... guess I have my project for the next 12 months or so.

thanks all for the ideas...

 

Not buying it. The wiring harness is a fixed entity and does not change between idle, and run. If your harness is toast, not only would it not run, but it would also not idle. The ECU closes the loop when it is satisfied with all the sensor readings, I think that with some luck, determination, and good detective work the solution is finding the sensor that is misbehaving, replacing it, and moving onto the next thing that is going to crap out.

 

Good point but issues with the wiring may be modifying the values and causing the failure to run right. Maybe..

At this point - having to keep a woman happy I am taking parts - all I can to make the daily driver a better vehicle. Later I may try again.

I did fail my HipRoverCratic oath, (first do no harm). As I disconnected the knock sensors I let one contact the exhaust manifold. Will have to repair that before I start trying again.

The truck will set for a while. With some fluid film to keep the iron oxide away.

Thanks

 

help me understand....does the tach currently work, or not? Tach is run by the alternator on these trucks.

 

no I have not seen the tach work since that drive home from where I had it stashed. At that point it ran great for the only time since I bought it. It must have been just a coincidence that it has not worked since. I was at one time hoping for a relationship but since my ultra gauge shows the correct RPM's the dash tach must not be related to the misfiring and such.. Unless someone can make a connection that I am missing..

Thanks