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328 bmissesb when I hit bumps under acceleration

2383 Views 9 Replies 0 Participants Last post by  joe pino
My 328 has developed an intere

My 328 has developed an interesting problem. When I accelerate and hit a bump, from the small round lane divider to larger frost heaves, the car misses as if it's not hitting on all the cylinders. It only happens if it hits a bump of some kind, and only under acceleration. Ideas?
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Sounds like it could be a bad/

Sounds like it could be a bad/loose spark plug connector ? are all your plug wires still held place in with the plastic loom clips?

If it's not something simple like that then it's likely a wiring harness connector/wire end loose.

I'd let the car idle and start jiggling wires (on the left side) gently to see if it can be induced to miss after checking to make sure all the plug connectors are tight first and the boots pushed in snuggly. Also gently jiggle the wiring harness connections on the coils.

Let us know if you find something.

Hello Jim,

This is kind of

Hello Jim,

This is kind of a tough one.

Not sure how mechanically inclined you are so I'll divide this into two sections, one for the easy stuff anyone could check themselves, and another one where you need to be slightly mechanically inclined or you may need your mechanic to check.

easy stuff
1. check to make sure your fuel pump relay is in secure and contacts/tabs are clean
2. check to make sure the same with the fuel pump fuse
3. maybe try switching the relay for another one with the same last 3 numbers (113) just for kicks.

I'm grasping at straws here, but these things are simple enough you could try them tonight and you'd know tomorrow (that's if the problem is fairly consistent)

tougher stuff
1. check the connections on your fuel pump
2. check all your (secondary) ignition wires - the ones from the coils to the caps - and the ones in each of the caps - check to make sure they're secure. (you're gonna have to peel back the protective boot which itself is sort of a hassle)
3. check to make sure all your wires are secured into the extenders and the extenders into the plugs (make sure your plugs are tight)
4. check to make sure the bosch connector on your frequency valve (lambda valve) is clean inside and secure (unplug it and look at the little connections inside make sure they're clean and tight). (to see what I'm saying look at page 68 of your owners manual - items G and D.)
5. make sure your computers grounds are clean (trunk, right side - peel up the carpeted cover, undo the 10mm screws, lift up the whole assembly and check)

jeez, I hope this helps. This is kind of a weird one.

If anything else pops into my head I'll write some more. Believe me, there's alot more to check, I'm just saying start with these.

Let us know.

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Hello JR,

It took me so lon

Hello JR,

It took me so long to write what I wrote (and I ate dinner)
, I saw you had posted after I hit the "post" button.
Oh well

Jim, check everything out and let us know.

When you wiggle stuff while the car is idling, wear some shop gloves.
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You're list looks better t

You're list looks better than mine Joe, I was writing in a hurry :)

I didn't think about the relay angle.
I tried what I could based on

I tried what I could based on what you pointed out for me, and still no luck. I took it to the shop yesterday and it had something to do w/ a sensor near the flywheel? It is repaired now, and wasn't expensive.

Thanks for the tips!
Flywheel sensor or TDC sensor.

Flywheel sensor or TDC sensor...there are three total.
I think because Jim has a 328

I think because Jim has a 328 he only has 1 Flywheel and 1 Pulse Generator. Probably the Pulse Generator.

308's have 2 TDC pickups and 1 flywheel, hence the 3 David is talking about. (1 pickup for each of the Magnelli ecu's)

Great that you got the car fixed.!

Yeah, it was something you would of had to take it in for anyways, you need a scope or DMM to read the pulse generator. (that's why I kinda said towards the end that "there's more to check".

It was worth a shot though.
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The receipt says something lik

The receipt says something like 'cleaned and sealed the plugs for the engine wiring harness and the flywheel sensing harness'. Don't think I could've figured that one out.

Thanks for the help guys.
Yup, and then again, it could

Yup, and then again, it could be something as simple as a connection.
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