No Start, 3500 Fiero not finished

[LZeppelin513]

I am at the tuning stage of the install but am new to it. The car was starting but it was running very poorly. Now today the car will not start.

There is 45 psi fuel pressure while cranking. I sprayed some starter fluid in the tb and nothing. I pulled the front spark plugs and they were wet with fuel but otherwise ok. I pulled a plug wire and held it near a ground and watched as the car was turning over. It would spark once then nothing. Try turning over, spark once and then nothing. I swapped coil packs but there was no change.

What is the next logical step?

Thanks much,
Blake

[bszopi]

Possibly an issue with the CPS or its wiring? If the ICM doesn't know where the crank is, its not going to fire the coils.

[CNCguy]

X2 on what Brad said. If you had to modify the CPS~ICM wire, be sure to check it thoroughly for tight connections and proper twisting. We had a customer chasing a similar problem only to find that one of the terminals on the ICM end had been stretched open.

Another thing to check since you have an external crank trigger is the gap between the CPS and wheel. I install them with a .03~.05" gap. If you do not have feeler gauges a piece of cover from a pack of matches will work. Also, verify that the small tip of the CPS is over the wheel.

[LZeppelin513]

Thanks for the help. Good news and bad news. I ohmed out the CPS-ICM wire and found it had an open so I re-did that with a different connector (the connector at the CPS was bad) and all new wire. Now I am getting constant spark when I observe at the wire while cranking. Bad news is that it still will not start??? Doesn't even try even with starter fluid.

So to reiterate, it was starting and running (poorly) a couple days ago but now nothing. I am stumped.

[bszopi]

For the wire, did you ensure it was twisted properly? Also, what type of wire did you use? I'm not sure if the type of wire matters, but I know for sure that the twisting of the wire (min 7 twists per ft IIRC) is definitely required for a good, noise-free signal.

[LZeppelin513]

I used quality automotive wire and got about 11 twists per foot.

[CNCguy]

Also be sure that the polarity of the wires did not get swapped.

[LZeppelin513]

Thanks, Pin a to a and c to b which is how the diagram shows.

[LZeppelin513]

Also forgot to say, I re-checked the cps gap and its .05"

[CNCguy]

Have you tried scanning during cranking to see what the ECM shows for RPM? Just curious if it is showing a constant speed or jumping around.

Although it's unlikely to be the problem, verify the trigger wheel is spinning true. Have someone crank it over while you watch the CPS gap. There should be very little change in the gap as it spins. A burr or piece of debris on the face of the dampener can make the wobble.

Edit: The pin to pin wiring looks right to me.

[TGP37]

It seems like the ICM thinks the engine is rotating backwards.

[Joseph Upson]

You need a timing light and a TDC mark on your balancer to make sure you have spark at the right time. It's possible with an internal 7x not sure with the external, to install it backwards. Although it's a direct ignition system I still made a couple of timing marks since I was dealing with code59 and a custom 7x trigger to make sure spark was occuring in the proper area.

If you confirm proper spark proximity and order and it still will not start even with starter fluid, you then need to make sure the spark intensity is good, a yellow spark is no good, it should be bluish in color. You also need to be sure the engine is not being flooded.

It's not easy at this point but removing the number 1 spark plug and using a long rod of material that will not damage the piston will allow you to get a good location of TDC with the engine in the car.

Be careful with the starter fluid, that stuff can remove parts from the engine without loosening any bolts.

[LZeppelin513]

I changed the spark plugs and now it starts and is running better than ever. The CPS wire pigtail open must have been causing all the missing I was getting the first week and then when it finally went and the car wouldnt start I fouled the plugs trying to get it started again.

It seems a lot more stressful when stuff isn't working right after an engine swap because there could be so many little things wrong along the way. But now the car is running great and needs some tuning to be perfect. I am pretty excited right now. Thanks for all the help.

-Blake

[CNCguy]

Very cool. Plugs can get fouled pretty quick when there's an ignition problem or rich condition. Been there a few times. Hopefully you can start making some good progress on the tuning now.

[pocket-rocket]

May want to give the oil a sniff test to make sure it isn't saturated with fuel now. Change it if it is.