I have just completed the 200,000 km service on my 1993 European model 3000GT Twin Turbo, changing all the fluids, filters, iridium spark plugs, water pump, oil pump, and complete timing system with all the belts, pulleys, and rollers (thanks Joe for the YouTube tutorials).
When I restarted the engine, the vehicle was running on four cylinders. There were no suspicious noises from the timing system and the timing was still correct. However, I noticed that cylinders 3 and 5 were not receiving any power. I checked the coils, but they were all fine. I then checked the ignition module (MD152999) and replaced it with a new one. The problem remains the same: the car starts, runs on 4 cylinders for 15 seconds, then the engine light comes on and the engine stops.
I admit that I don’t really know what else to do to solve the problem, so any advice you can give would be welcome.
Sorry for my Google-translated English: I’m in France.
Off the top of my head, 3 and 5 share the same coil. If this is the case and you have swapped the coils round to confirm that it is ok, I would be looking very closely at the wiring that goes from the ptu to the coils. These wires are exposed to a lot of heat and often breakdown internally. This is not always visible so you will need to meter them to confirm perfect continuity. Let the group know how it goes.
Hi Jo, Many thanks for your reply. I miss to mention it but I already did it and the connection are ok from the PTU (brand new) to the coil. I hope it does not come from the ECU but if this is the case is there any way to test if the ECU is at the origin of the issue ?
I have only seen this problem caused by the ecu 1 time myself but I am sure that others would have seen it so it is a possibility. You can connect a scope to wires coming from the ecu to check the pulses are there.
Hi there. Angela Smith here from NZ. You say that you did the rollers as well. I did the same and ran on five cylinders. one of the rollers was misaligned on the lifter. hard to spot but it honestly sounds like that’s all it is. You’ll need to remove the rocker covers un fortunately but you never know - it may be one of the lifters in the front bank.
Thanks for the info, I have HHH software and I’ll try a diagnosis to see. However, what intrigues me more and more is that I feel like I’m dealing with two separate faults: one concerning the lack of ignition on two cylinders, and the second concerning the engine cutting out 15 seconds after the engine control light comes on on the dashboard. In fact, I don’t think that on this model, the engine would shut down on its own if certain cylinders were not working: thank you for your confirmation.
Thanks for the info, I’ll keep that in mind. I still think it’s an ignition problem, but I’ll explore that option after I’ve explored all the electrical possibilities.
Hello all, after several test with a software Hand Held Halo on the OBD1 plug from my car, I had 2 errors code. First one is code 22 : engine speed sensor and second is 23 : TDC Sensor. This 2 code looks very different in term of issues on the car and due to the fact that I did the complete timing system, I will try to test the TDC Sensor if by chance it could be the source of problem. As usual, your comments are welcome