The last post was closed because it was off topic. Sorry I should have been more clear.

My GM made car that use a 730 ECM, let's say it's my 86 Cutlass with a TPI system from a 90 CAMARO, instead of a Cavalier that uses a 730ECM as well.

So I drove my Cutlass, which has a TPI fuel injection systen from a 1990 Camaro, into the garage...

Thanks again for any help
Steve

 

If that '90 Camaro engine happened to have a couple of dual coils, you might want to check the cam position sensor to make sure there is signal. Signal levels on some sensor can be pretty low while they are still functional. As long as you can get switching from the sensor, it should be good.

If the coils test about 0.1-1.0 ohms on the primaries, and about 5K ohms across BOTH secondary terminals, they should be good.

If the ignition module tests good, it should at least produce some spark when cold.

If the secondary wires have no damaged insulation and test at 500-1,000 ohms/foot, they should be good.

One thing to watch is the plugs. Gaps are critical, and fouled plugs can shunt all the spark energy without allowing a spark. And on a wasted spark system, BOTH plugs on a given coil must be connected or neither plug will get spark.

If this engine has a 3X or 7X crank position sensor, you may need to check that as well. That is necessary for ignition timing. The 24X sensor is used primarily for injector control, and if you're getting injector pulses (fuel), you can ignore the 24X CKP for now.

That's one strange "Camaro".

 

Speaking from some experience with those very odd "Camaro's" - if it's the setup with the 2 coil mounted on the rear of the block, next to the firewall, those seem to always crap out from my experience with those odd "factory one-off's." Even when they tested "Good."

 

Thanks guys. I had the module checked, and I would be amazed if all 3 coils would go at the same time. Either way I am going to grab everything from a wrecker and switch it out.

I posted this here because I am curious what else particular to the 730 and other sensors or problems that could cause the problem without setting a code or limp mode. The ignition system is wired almost identically, the crank sensor is wired to the module and the module is wired very similarly to the ecm as the dist cars.

The crank sensor of this special camaro read 908 ohm which is in spec. I am also going to make sure the timing chain didn't break some how.

I am really thinking it's a mechanical problem.

Thank you very much for the help, even if it's not an Fbody per say, most of the ignition trouble shooting should apply to both.

Thank You,
Steve

 

I just had one of these in a '95 F-Body early this week. Pay close attention to the plugs, wires, and crank trigger.

 

Update time.

I switched out the module and coil assembly with one I grabbed from the wrecker. Works perfect now, starts and no 4000rpm stumble like it had before.

With that being said, I had the old module tested at the parts store and it passed, makes me wonder about their equipment.

Thank you for all your help on this special Camaro.
Steve

 

Testing modules at a parts store is fine for a "Go-No go" test. However, many amplifier/switch modules fail due to heating. Test equipment usually doesn't subject the module being tested to the kind of current load and temperatures that would normally occur in service in the vehicle. The test is not 100% foolproof.

 

Very true. Thing is I know the equipment at the store heated up the module enough that you didnt want to touch it. When I drove the car in to the garage it was stone cold. Sat all night outside, it was about -5C when I drove it 10ft into the garage. There is no way the module was very warm. Still it failed in the real world and that's what counts.

Thank you again,
Steve