M30 no spark but plenty of fuel (FIXED)

[Digital]

Well after installing my custom driveshaft I have had my swapped E30 running for about two weeks until I have ran into a no start issue. The engine always started from the first time I turned the M30B34 over ( my car is a 1989 and the engine is a M30b34 that has been swapped over to Motronic 1.3) I have check power at the main relay and the fuel relay. I checked the Ecu grounds and powers, the CPS checks good according to the specs from the Bentley manual, the coil has 12 volts while cranking, the fuel pump runs and puts out fuel to the rail. There is no spark at the plugs or from the coil. I swapped my good coil from the M20 and still the same results. So I have narrowed it down to a dme or a faulty CPS sensor (even though it checks fine at the DME). Any insight will be helpful

[wildstoats]

Have you checked cap / rotor and coil wire?

[Digital]

I have checked the coil for spark to eliminate the cap and rotor and wires. And there was no spark from either coil I have checked

[Mr. Burns]

have you checked your other grounds aside from ECU?

I would go over all of them...

using M20 harness?

[Digital]

Using a M20 harness, the only grounds I have checked were at the ecu and my main ground at the block. Where else should I be checking for grounds at?

[Mr. Burns]

condition of ground on block? mine was pretty chewed up...

at this rate i'd double check all grounds...simply to rule it out

Reason I would think it's a ground is because you're saying it ran/fired up fine at 1st, and suddenly wouldn't get spark...

have you tried swapping out relays?

[Digital]

When I put the M30 in I made a new ground wire from like 0 awg aircraft wire, I jumped both the main relay and the fuel relay and still cranks but no spark.

[wildstoats]

When you say the coil has 12V while cranking where exactly are you testing? It really sounds like either the ignition control from the Motronic is messed up or the coils are bad (assuming they were both used coils). I have to say I'm not as familiar with the 1.3 electronics though.

[Digital]

I was checking 12volts at the positive side of the coil. I checked the negative side of the coil with a test light while cranking and the light was indicating that the DME was outputting a ground to the negative side of the coil. I tried my coil once again for spark and apparently it was there but very weak. Tested the coil wire for spark and it was very faint. There still is no spark at the plugs. It looks like the coil just had enough.

[Digital]

So being a cheap upgrade would you use a msd 8202 or fork over more money for a Bosch oem coil Or go for a e34 coil

[Bearmw]

The cheapest known good one I could find just to get it running. You could probably run an m20 coil without a problem.

[Digital]

Well the engine still will not start, I replaced the coil with a new e34 coil, replaced the plugs the cap and rotor for good measures. I get spark from the coil to the distributor, spark from the center of the distributor, but no spark to the plugs. I am looking for suggestions at this point, the car was running when it died nothing out of the ordinary was just cruising doing 25 down a side street. I checked the cps, the power and grounds at the dme, jumper both the main relay and the fuel relay.

[Ether-D]

Sounds like the rotor or distributor cap is cracked. Check for continuity between the spark plug sockets and the corresponding tabs on the inside of the cap. Then do the same with the rotor if you haven't already.

[Digital]

I installed a new Bosch cap and rotor and still no spark to the plugs

[Ether-D]

So no spark out of the cap? Check that rotor with a meter.