Dave M vin 03572
http://dm-eng.weebly.com/
Posts: 51
Yes, the warm up regulator on comes on when the engine is running which is what it's supposed to do I guess. It sounds to me like it's either the computer or the ISM. Thanks for the offer of letting me test one of your computers, I really appreciate it. I think what I'm going to do though is call dmch tomorrow and see if they'll do an exchange on the ISM since this one's still under warranty. If that doesn't solve the problem I will definitely take you up on your offer.
Thanks
Location: Reedsburg, WI
Posts: 4,026
My VIN: 5180
Club(s): (DMWC) (DCUK)
DENNIS
VIN 5180, Frame 3652, STAGE II, DM-eng Solid State Solutions (RPM Rly, Dm.Lt.Mod., Fan Fail Mod. , FAN Rly, HS.Rly) , HID headlights, SPAX user since 2009, Eibach springs, M Adj. Rear LCA's, DPNW poly-sway bar kit, DMCEU LCA Stabilizer link kit, DMCMW Illuminated door sills, Aussie Illuminated SS Shifter plate, REAL MOMO EVO Steering wheel, DELOREANA Extended View Side Mirrors w/ Heaters, DELOREANA LED Door Lights.
Yes history would help. If you have one of my idle ECUs, it does not buzz the ISM when the key is turned on. Mine would have a blue wire coming out between the two connectors or you could have an 11 pin unit I also sell.
The ISM wires pass through the bulk head connectors with is another possibility of failure.
Dave M vin 03572
http://dm-eng.weebly.com/
Posts: 51
Ok, I might be getting some of my acronyms mixed up. The car was at delorean of Houston back in the summer for a couple of months getting a partial restoration done. Basically just getting the car into running, driving shape. This is where and when the new idle motor was installed. This was one of a few new parts that were installed to get the car running. As far as I know the computer that's in the car is the original that it came with. They did not have to change this out. I was under the impression that the parts that were put on the car had at least a one year warranty.
Thanks
Location: Northwest Florida
Posts: 324
My VIN: Midproduction
It's a bad Idle Speed Motor. If you want to confirm, with the car off - unscrew it from the bracket and both hoses, hold to where you can see inside the airway facing the rear of the car. At this point put the key in and on run, you should see the ISM swing open and slowly close (over the course of 30 seconds). If it doesn't do this, it's stuck or dead. Again, these new chinese units are not very reliable (I've gone through two of them) .
Location: Reedsburg, WI
Posts: 4,026
My VIN: 5180
Club(s): (DMWC) (DCUK)
Okay,
New ISM’s don’t usually fail. Old one’s can suffer from Rust in the bearings or carbon build up in the valve end.
I think you should At least pull the short connector hose off the ISM that connects to the Cold Start tube. The tube will pivot towards you enough to slip the hose off the ISM. Then just push it aside so you can see in the Port with a Light. You should be able to move the valve with a blunt tool or pencil with eraser head.
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DENNIS
VIN 5180, Frame 3652, STAGE II, DM-eng Solid State Solutions (RPM Rly, Dm.Lt.Mod., Fan Fail Mod. , FAN Rly, HS.Rly) , HID headlights, SPAX user since 2009, Eibach springs, M Adj. Rear LCA's, DPNW poly-sway bar kit, DMCEU LCA Stabilizer link kit, DMCMW Illuminated door sills, Aussie Illuminated SS Shifter plate, REAL MOMO EVO Steering wheel, DELOREANA Extended View Side Mirrors w/ Heaters, DELOREANA LED Door Lights.
Posts: 51
There have been some idle ECU failures. It's mostly the transistors that drive the ISM that fail. If your ISM gets a short circuit then that will probably blow the drive transistors. I don't usually test the ECU cores I get back from a customer but I have tested some of them were bad.
There also are connections issues that could make it fail. Mostly the ISM connector but the bulk head (connectors in the ignition coil box) also get corroded.
Dave M vin 03572
http://dm-eng.weebly.com/
Posts: 605
Somebody finally should write a how to - how to test the idle system - and keep it on top of the how to list.
how to perform a quick test of the idle motor can be found here many times
and Dave is 100% right, most failures of the idle ECUs are the power stage transistors.
As there is a PWM switching with ~100Hz - it can't be measured with a multimeter.
to an earlier question - which does not help now to find the problem:
depressing the idle microswitch changes that PWM, because the speed setting
changes from 775 rpm to a higher value. That's not a guess, I measured it and
have the schematic.