Another "my car won't start" topic

[Sublime69]

I was going to get my cop car ('89 Diplomat) out of my dads garage today because I was going to take it to renew tags tommorrow plus Wed is bowling night.

Turns out, it won't start. It was running perfectly fine about 4 days ago when I moved it to a different place in the garage. I haven't touched anything on the car.

I tested for spark, no spark. I swapped ECU's with one on my dads Road Runner that's awaiting a resto (Brand new MP ECU, well it's 2 years old but never used only once to see if the RR would start). Still no spark. I swapped coils with one on the RR. Still no spark and a new coil. I check the cap and rotor, they're fine. Rotor turns, wires are brand new and fine etc etc.

I'm out of ideas. I touched nothing on this car and my dad hasn't even been in there because he's been working. Is it possible I had 2 bad ECU's? The RR is a 400 BB, are the ECU's programmed the same for a SB? It's all MP stuff too. My dad put a brand new ECU on his Cuda last summer and we took it to a show in Oct. It went out this spring not even 6 months after installing it. Put on the cheap ECU that's been on the car for the last 16 years and it fired right up. So I'm leaning towards a faulty ECU. But if it is, then the one that's been on the RR is bad and it's only been used once and always stored in the shop. I'm beginning to think MP makes junk.  Also, I did jump the balast resistor, still nothing. The car does make a "cough" after I stop cranking it but no spark on the tester.

Any other ideas? Thanks

[nascarxx29]

Being you swapped out coil and ECU with a known good one?..Do you have + power at the + coil connection And be sure the ECU is well grounded .Try a ballast.If not that it might be the pick up coil in the distributor or its gap.You can get a 12 volt testlight pointed end on neg coil terminal.With other the clip end of testlight on a good ground.And while its cranking over you should see the light flicker.Another way I tested pick up coil.Was unplugged at distributor and probing dist leads with a ohmeter.For a resistance reading  
This is the pick up coil which is like a electronic set of points thats triggers by the reluctor wheel in the distributor
http://cgi.ebay.com/ebaymotors/Mopar-1972-up-Distributor-pickup-coil-assembly_W0QQcmdZViewItemQQ_trksidZp3286Q2em20Q2el1116QQhashZitem22f13dce48QQitemZ150076247624QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessoriesQQsalenotsupported

[Sublime69]

Thanks for the help, I'll look into those other things today.

I was assuming I swapped out my ECU for a new one, but the thing is:

We put a brand new MP ECU (orange box) in my dads Cuda last August, drove it to 2 car shows, last one in Oct for a grand total of maybe 75 miles and went to start it this April and the ECU was bad. He put the old one in that was in the car for the last 16 years, a cheap one, and it works fine. Pretty pathetic when a new MP one goes out but the 16 year old cheapo is still working fine.

The RR had a brand new MP ECU in it 2 years ago, orange. We hooked it up to see if the car would start and that's the only time it was used. Car has been sitting inside awaiting a resto ever since. Now it may be bad.

I bought a MP electronic ignition conversion kit, with orange box, last summer. Now, a year later and maybe 5K miles this one may be out.

I'm picking up a cheapo ECU from Napa today. If the ECU was the problem this just tells me MP makes complete crap and I will never buy anything from them ever again.

[nascarxx29]

I havent had much luck with orange boxes either .I think the better module was NAPA TP 50 If I remember correctly

[GN]

I had a similar problem, it turned out to be the ballast resistor.

[nascarxx29]

Ballast is the less expensive part to try .I recall having similar problem just kept cranking .And when you gave up it would kick back.It was module most of the time.