1996 Park Avenue Misfire

[hairball29]

Hi, all

I have a Buick Park avenue which is getting to an age where it's starting to become more trouble than it's worth, but money does not allow its replacement so i wonder if you guys could help me diagnose its most annoying issue.

When cruising at any speed on an even throttle it's fine, but as soon as it gets a little resistance such as a hill or a little more throttle for speeding up, it starts to shudder like it has a misfire.

If I floor it, it goes away but only until I back off again. Its 'check engine' light is on, but so far I have not had it diagnosed professionally. I wondered if this is something that they suffer from and perhaps is a known issue, or do I have to bite the bullet and take it in.

It's had a fuel pump recently and it has no other running issues but for that one.

Thanks in advance.

[HotZ28]

Have it scanned for codes first. Most big box parts stores will scan it at no cost. More than likely, you have misfire codes, which may indicate faulty plugs, wires, or coil(s).

[hairball29]

Thanks for that.

Forgive my ignorance, but I'm pretty new here and I'm not sure which stores would have that service?

I know Walmart has an auto department, but I think they're more tires and batteries than anything.

[Tech II]

Most auto parts stores, like Autozone will scan for free.......

yes it does sound like a misfire....probably will set a P0300, which won't tell you which cylinder is misfiring.......

Chances are, plugs and wires will solve your problem.....pull wires one at a time off the coil terminals....may find arcing/carbon on the terminals......usually can just clean/sand the terminal, but the wires should all be replaced and with new OEM plugs....

If you still have a misfire, then coil output will have to be checked with a spark tester.....

[hairball29]

Originally Posted by Tech II

Most auto parts stores, like Autozone will scan for free.......

yes it does sound like a misfire....probably will set a P0300, which won't tell you which cylinder is misfiring.......

Chances are, plugs and wires will solve your problem.....pull wires one at a time off the coil terminals....may find arcing/carbon on the terminals......usually can just clean/sand the terminal, but the wires should all be replaced and with new OEM plugs....

If you still have a misfire, then coil output will have to be checked with a spark tester.....

Thanks,

I will take it to one of those places. It seems cables are not crazy money, i guess plugs won't be either so i'll have a go at those and see if it makes any difference.

[hairball29]

Hey, thanks for your advice.

I got some new leads since they were pretty cheap and replaced them all. I noticed that 1 lead at the coil end was a bit brown looking, but one was very black and full of carbon.

I changed all 6 and now it runs sweetly.

I also removed the mouse nest from between 2 of the injectors under the plastic cover, but I doubt that affected performance.

Thanks again.

[Tech II]

Just double check the wires under the engine cover.......have seen the mice eat the insulation(usually can just retape them for a repair, unless the wires are damaged themselves).....don't want wires shorting out to ground or against other wires.....can affect the injectors or the purge valve...