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240 LH 2.4 Spark Issue

sideways242

New member
Joined
Nov 3, 2017
Location
Sacramento
Hola Volvo Brethren,

First I'll explain the car and the setup to limit confusion. I've got a 1984 Volvo 242 with a rebuilt b230ft and t5. The car was running on the stock k jet system, but I preferred the thought of a smoother idle, diagnostics and the other pros of LH 2.4 so I swapped in a fresh harness. long story short the car starts and runs on two cylinders with a weak spark. I have checked (on my LH 2.4 245) or replaced the following components: ECU, EZK, CPS, Powerstage, Distributor, Rotor, Cap, Wires, Plugs, and all ground connections. When I crank the car with the coil wire unplugged I get full bright spark grounding over and over. The timing has been reset multiple times and has been confirmed by timing light to be dead on, but still only spark on cylinders one and three. I am so lost and anything would help at this point in time.

Thanks!!!:)
 
Have you checked that the distributor drive shaft is oriented correctly? If you take the cap off, there's a groove on the edge of the distributor body. The tip of the rotor should be ~centered over the groove when at TDC. The actual spark timing for LH2.4 is controlled by the EZK and CPS, but the distributor rotor still needs to point at the correct cylinder post when the spark fires.

Edit: one other thought, are you using a LH2.4 coil, with the original K-Jet ballast resistor bypassed? If the ballast resistor is still supplying the coil, it would result in low coil voltage when running (but full voltage when cranking).
 
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Have you checked that the distributor drive shaft is oriented correctly? If you take the cap off, there's a groove on the edge of the distributor body. The tip of the rotor should be ~centered over the groove when at TDC. The actual spark timing for LH2.4 is controlled by the EZK and CPS, but the distributor rotor still needs to point at the correct cylinder post when the spark fires.

Edit: one other thought, are you using a LH2.4 coil, with the original K-Jet ballast resistor bypassed? If the ballast resistor is still supplying the coil, it would result in low coil voltage when running (but full voltage when cranking).

I have the distributor all lined up with the pesky notch at TDC which is what I thought it would be at first, but no luck:-( I have the full LH 2.4 harness, but is there still a ballast resistor I need to bypass? I haven't ever seen one but Ill double check to be sure. Thanks!
 
The easy test is to measure the voltage on the coil with key on, but not running. You should see very close to full battery voltage. If the ballast resistor is still in the circuit, voltage will be much lower at coil. The ballast resistor, at least on my 85 k-jet, was on the fender roughly under the wiper motor. It's a ~3" long 1/2" x 1/2" white ceramic thing, with spade connectors on each end.
 
The easy test is to measure the voltage on the coil with key on, but not running. You should see very close to full battery voltage. If the ballast resistor is still in the circuit, voltage will be much lower at coil. The ballast resistor, at least on my 85 k-jet, was on the fender roughly under the wiper motor. It's a ~3" long 1/2" x 1/2" white ceramic thing, with spade connectors on each end.

Yeah, no ballast resistor. I just went out to check and I have 11.85v with the key on.
 
Did you have the dist pulled out? Is it timed correctly?

Its confirmed to be 100% on time, and I've tried 3 different distributors out of other LH 2.4 cars and they all do the same thing. I was just reading another post of yours where you mentioned adding a switched 12v to the blue wire going to the coil? If I already have spark coming from the coil should I still do this? whats the benefit? Thanks!
 
You need power to the coil key on. That's what the wire does.

Do you have steady spark coming out of the coil itself? A test light between coil negative and ground works great too.
 
You need power to the coil key on. That's what the wire does.

Do you have steady spark coming out of the coil itself? A test light between coil negative and ground works great too.

Yes, a full spark coming from the coil which is the weird thing!
 
If you have consistent steady spark from the coil, that really only leaves the dist timing or cap/rotor.
 
Any diag codes from the EZK after trying to run?

[And just to cover the bases, re-check your plug wires. 1-3-4-2 as the distributor rotor moves in a clockwise direction as viewed from above.]
 
If you have consistent steady spark from the coil, that really only leaves the dist timing or cap/rotor.

I've got the distributor aligned with the notch on the side at TDC. Honestly, at this point, it seems like distributor timing, but from everything I know, I'm doing it correctly!!!
 
Any diag codes from the EZK after trying to run?

[And just to cover the bases, re-check your plug wires. 1-3-4-2 as the distributor rotor moves in a clockwise direction as viewed from above.]

I'll check codes now because all the wires check out great! Thanks!
 
Is that little black plastic alignment piece still there? Aligning the rotor with the housin is great, but that assumes you have dropped the dist in correctly on the correct tooth. If you drop it in on the incorrect tooth it doesn't help lining up the rotor with that notch.
 
Is that little black plastic alignment piece still there? Aligning the rotor with the housin is great, but that assumes you have dropped the dist in correctly on the correct tooth. If you drop it in on the incorrect tooth it doesn't help lining up the rotor with that notch.

Realllly? I've never even seen that piece, but I assume it would slot in where the bolt goes into the block?
 
Is that little black plastic alignment piece still there? Aligning the rotor with the housin is great, but that assumes you have dropped the dist in correctly on the correct tooth. If you drop it in on the incorrect tooth it doesn't help lining up the rotor with that notch.

And would that matter if I'm getting spot-on timing with a timing light?
 
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