Plugs, misfires, resets

jsmcortina · Post by **jsmcortina** » Tue Jul 11, 2006 1:41 pm

A bit of info.

The other week I'd fitted a different engine to my car (3.9 rover instead of 3.5) and had extreme difficulty getting the trigger wheel to work right and had misfires and all sorts of weirdness. Turns out the engine had worn rings and was chucking oil into the cylinders fouling the plugs. This was causing misfires and interfering with the wheel decoding. I didn't get any resets though.

I pulled that engine out and refitted my old 3.5 (after replacing the damaged pistons) and it fired right up but misfired and had processor resets. I regapped the VR sensor to where it used to be and it ran a lot better with a few misfires.
Last night I pulled the plugs and they were rather fouled up. So I heated the ends with a gas torch to burn off the deposits and it runs normally now.

I have found that these plugs (NGK B7ECS) are non-resistor and unfortunately resistor plugs are not available in that heat range and tough design. I've ordered some even more expensive colder resistor plugs to try. (BR8ECS)

James

jonfx4com · Post by **jonfx4com** » Tue Jul 11, 2006 4:18 pm

Hmmmm. Maybe you just gave me hint about my problem with EDIS and tach spikes. After posting my question this evening I spent a few hours researching since nobody seems to have any answers and it seems that EDIS with non resistor plugs is prone to problems. My problem is finding resistor plugs for an ancient vauxhall slant 4 engine that uses weird plugs! I wonder if in line suppressors would help? If so they may solve your problem too, I believe they are just resistors.

I have quite extreme spikes at higher rpm massive spit backs down the intakes and some resets (ms2 684)

Jon

jsmcortina · Post by **jsmcortina** » Wed Jul 12, 2006 12:59 am

DOHC Granadas and Sierras used suppressors on the dizzy cap. I wonder if they would be suitable.

James

jonfx4com · Post by **jonfx4com** » Wed Jul 12, 2006 1:02 am

Thought they were all EDIS?

Jon

jsmcortina · Post by **jsmcortina** » Wed Jul 12, 2006 1:58 am

The DOHC engine uses a 36-1 wheel on the back of the crank, but has a single coil and "locked" dizzy on the end of one of the camshafts.

James

keithmac · Post by **keithmac** » Wed Jul 12, 2006 11:29 am

On Magnetti Marrelli (sp) motorcycle ignition ecu`s non resistor plugs and caps can kill the ecu in a matter of 100 miles! (seen it a fair few times and Â£200 for a new moped ecu!).

I had a loose connection on my idleDC Valve, this caused random resets and the car actually stalled while driving a few times as well, put it down to interference/spiking from the loose valve connection.

jonfx4com · Post by **jonfx4com** » Wed Jul 12, 2006 12:55 pm

I found some bpr6fs NGK plugs that will fit my engine, should be in tommorow so with luck that should answer my question. If not I can try these DOHC ford suppresors.

Jon

hobieboy · Post by **hobieboy** » Thu Jul 13, 2006 10:03 am

James, please keep us posted about your findings with the BR8ECS plugs.
I was using B8CS plugs in mine and plan to use them after Megasquirt so would be EXTREMELY interested in knowing your results. I gather B8 without the R means its the non-resister type?

thanks.