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Afternoon all

I'm finally just getting some more time to work through to get my 1997 2.5 V6 Probe up to scratch. I bought it last year as a 22k mile car that had been dry stored for many years. In great condition but wasn't starting so been working through all the possibilities.

Just going through the basics and can see that the previous owner has done the immobiliser bypass. Seems done correctly but they left the unit in the car and plugged in which seemed odd to me. I was guessing that if the bypass was all done to the cabling prior to the immobiliser that you can just unplug and remove the immobiliser at that point?

When I started it the immobiliser red light just flashes. The engine cranks nicely but doesn't fire. So I unplugged the immobiliser and of course the red immobiliser light no longer flashes as expected. The bypass is still valid and in place as the pairs have been joined on the cables before the immobiliser unit.

So I pulled a spark plug and have the one I pulled had no spark. So checked the disty cap and it seems in pretty good almost as new condition. Next step back is the main dizzy/ignition unit.

So not sure if it could be the main dizzy/ignition unit or possibly a faulty crank or cam CPS. Not got my head entirely around this engine just yet so not sure if a CPS or any other items could cause a no spark. Or could a bad bypass stop this.

The previous owner had done some diagnosis as when I bought the car it had the fuel rails/injectors removed as I think he thought it was a fuel supply issue. So they pulled these and the 30a fuel pump fuse to stop the fuel supply while the fuel rail was removed. I have re-installed the fuel rails but left the 30am fuel pump fuse out for the moment.

Am I right in thinking I should get a spark OK with the 30am fuel pump fuse pulled and no fuel delivery?

Seems I need to get a spark first then if a fuel issue after then deal with this as a sperate issue later. We only need a spark and fuel with the correct timing so pretty simple.

Does anyone think the no spark issue could be a bad dizzy/ignition unit?

Mine is a TOT57072 KLY1 with an A.

I've looked through loads of posts here and elsewhere to get my head around the issues and the engine and just starting to lean more. Anyone got any obvious thoughts or ideas with a crank no start/spark issue please?

Thanks in advanced.

Sounds like symptoms that could point to the CPS or dizzy being potentially the issue so seems to make sense to pull/clean the CPS first. Then maybe replace it anyway to eliminate the CPS.

Does anyone know if you need to or it is easier to remove the OSF wheel to get access to the CPS? Looks a bit tight to get in there without taking the wheel off.

Hi Rockits,
if your car is a 1997 car, then I very much doubt that the immobiliser has been bypassed, because you would have a Temic (chipped key) system. What makes you think it has been bypassed? what type of key do you have? I wouldn't disconnect the immobiliser and leave it plugged in.
Have you tried to pull the grey plug near the oil dipstick apart, give it a quick clean and put back together, as it is a known failure point.

After you have looked and checked all of that, the next possibility is the Dizzy.

rockits wrote: ↑

Mon Jul 21, 2025 2:33 pm

Sounds like symptoms that could point to the CPS or dizzy being potentially the issue so seems to make sense to pull/clean the CPS first. Then maybe replace it anyway to eliminate the CPS.

Does anyone know if you need to or it is easier to remove the OSF wheel to get access to the CPS? Looks a bit tight to get in there without taking the wheel off.

see my response re your original post.

Micron wrote: ↑

Mon Jul 21, 2025 2:36 pm

Hi Rockits,
if your car is a 1997 car, then I very much doubt that the immobiliser has been bypassed, because you would have a Temic (chipped key) system. What makes you think it has been bypassed? what type of key do you have? I wouldn't disconnect the immobiliser and leave it plugged in.
Have you tried to pull the grey plug near the oil dipstick apart, give it a quick clean and put back together, as it is a known failure point.

After you have looked and checked all of that, the next possibility is the Dizzy.

Thanks for your post.

It is a Bosch unit and I have the key without a fob I'm guessing with a transponder inside. It has been bypassed as I can see the cables joined as per the exact bypass instructions.

I'll take and add some pics.

Does the Bosch have a remote fob and the Temic have the key with transponder?

Added a few pics to show the immobiliser unit and keys I have also the bypass wiring.

Am I right in saying that the keys I have should be for a Temic immobiliser and the Bosch unit should have the remote fobs?

That distributor number is a 95 or before unit. All this points to it being a 95 or earlier model

Trism wrote: ↑

Mon Jul 21, 2025 5:04 pm

That distributor number is a 95 or before unit. All this points to it being a 95 or earlier model

Yes, seems that way. The car is registered 03/1997 but just found the VIN build year thread on here. The 10th letter in the VIN shows it is an R or 1995 build year. So a later registered car but not the later build it seems.

So could make sense it is a Bosch immobiliser and earlier disty unit. So maybe is missing the remote key fob?

Is the remote keyfob still needed and needs to be used even if the Bosch immobiliser unit has been bypassed and removed?

I would check the joints, also that the correct cables have been jointed.

Also check all the other things previously mentioned.
If you have an early car then it is very likely that the Dizzy is faulty, caused by the Immobiliser.