engine sputtering after spark plug / wire change

[cpandrewschmidt]

Hi all,
I ordered a Bavarian Auto Tune up kit for my 1991 e30 325i. I had some questions I'm hoping you can help with.

Over Christmas I installed a bunch of engine tune up parts from my order (timing belt, thermostat, water pump, distributor cap etc) Car ran great and everything normal after those changes. I then put the car back in storage.

Last week I later went to install the spark plugs as I hadn't done that. I realized when I put them in they didn't fit with the old wires on the car. The back part of the new plug was too big for the old wires. So, I ordered bavauto's performance wire set and installed the new plugs that came with the tune up kit. Car fires up fine but the car now runs rough with only the plugs and wires being the difference of installed parts.

1. Do the spark plugs with that kit come pre-gaped? if anyone knows
2. Should those plugs have been paired with the performance wires for my car?

I know the M20 engine isn't all that high performance so I'm wondering if it can't handle these plugs/wires? Just looking for ideas to help make my troubleshooting easier. Thanks much.

Andrew

[dnguyen1963]

Which spark plugs did you get? You need to unscrew the caps on the plugs before it will fit into the wire receptacles. Take out the caps and put the old wires back in to see if the problem goes away.

[cpandrewschmidt]

thanks, i should have tried that but unfortunately stupid me already threw away all the old stuff :(

andrew

[MR 325]

So, did you unscrew the tips from the new spark plugs? What brand of plugs did you get? Part number?

Spark plugs do come pre-gapped but it's never a bad idea to check. Yes the engine can "handle" the new wires.

[cpandrewschmidt]

I got both from Bav Auto. I can't link the direct part but these are the part #s.

BavAuto Tune up kit : part # TUK 2.5 87-91 It came with Bosch plugs, i don't know which kind.

Bavarian Autosport High Performance Ignition Wire Set Part # : 12 12 1 720529P

The new plugs seem to fit just fine in these wires without unscrewing anything from the spark plugs.

[MR 325]

I got both from Bav Auto. I can't link the direct part but these are the part #s.

BavAuto Tune up kit : part # TUK 2.5 87-91 It came with Bosch plugs, i don't know which kind.

Bavarian Autosport High Performance Ignition Wire Set Part # : 12 12 1 720529P

The new plugs seem to fit just fine in these wires without unscrewing anything from the spark plugs.

We can help you if you can't provide information.

I can also promise you that the tips needs to come off the spark plugs.

[cpandrewschmidt]

I'll snap some pictures over lunch. I did post the part numbers for BavAuto's website. You can't copy and paste their links as the link only goes directly to their homepage for some reason.

Thanks for helping, I'll update in a couple hours with the pictures of what I have.

Andrew

[meengreene30]

.

Yes you need to unscrew the caps on the plugs as MR325 stated. Should always check the gap at .027. My buddy had issues with those $200 8mm bavauto wires also, switched back to Bosch.

[cpandrewschmidt]

Thanks, I pulled them over lunch. They definitely had that cap over that screw part. I removed the cap, re-installed and started the car. Started and idled fine, which it did before,. driving was where i noticed the sputtering. Haven't had a chance to drive it but hopefully that was the issue.

PS - why is that cap there then? I thought most new plugs left that on? Should that always be removed? I haven't really changed plugs in a LONG time.

Thanks!
Andrew

[dnguyen1963]

Spark plugs are made not just for E30. It's for other cars too and they fit just fine without the need of removing the caps.

[cpandrewschmidt]

hi all,
so i got the caps off. car drives similar still. it sputters intermittently during acceleration and deceleration, but there's no rhyme or reason to when it does it. When car is at cruising speed it runs great.

any other thoughts on where to try looking first? thanks

Andrew

[BMWManiac]

When you installed the ignition wires onto the spark plugs WITH the caps still on them, did you hear/feel them snap into place? I don't know what kind of wires they use, BUT, the set I once bought from Advanced Auto for my E30 REQUIRED the caps.....

[cpandrewschmidt]

The wires i got from BavAuto did allow the new plugs to snap into place, which is why i thought i needed to get newer wires. I figured the technology changed on plugs/wire since the previous owner might have changed them. When pulling the caps from the new wires I don't get that same "snap" but they still work and the car still runs without the caps.

The old plugs that were pulled from the old wires had the had the caps off.

But either way when i'm running the new wires and plugs with or without caps I get the same issue.

So, could be wire related or something else now that the engine has a totally fresh new tuneup. Wish i didn't pitch the old wires to test those out.....I don't really want to buy another set that aren't the "high performance" ones.

Andrew

[BMWManiac]

Put the caps back on the plugs then if you want to use them with the Bavauto performance wires. The OEM wires from BMW require you to remove the caps.

As far as the issue, I would go back to the BMW ignition wires WITH the spark plugs/cap off and see if the problems are still there.