Picked up a '98 LS with 180K and did a complete tune-up; Plugs, wires, cap, rotor, fuel filter, pcv valve. Now it spits a Code 71 (misfire) and sometimes 73 (misfire)too--it didn't do that when I first got it. What could be the problem? I think it may be defective NAPA plug wires, but I dunno. Thanks, Dudes.


Modified by mattoien at 11:57 PM 2/3/2004

 

Any ideas, Guys?

 

bump

i have no idea, i'd like to know this

 

Bump... No ideas? There are tons of you out there?!?

 

did u put the plug wires on correctly on the dist? make sure they are in the correct order.

 

I've heard about some Warranty Bulletins from Acura on ecu's throwing misfire codes... You may wanna check with your local dealer, and have them pull up the warranty bulletins for your car...

 

Downey, it seems to run fine, and I know I hooked 'em up right. If they weren't, it would run like a turd.

4U2NV, that's a great suggestion, I'll have to check into that. Thanx!

 

Yeah, the only thing I could really think of is the cap/rotor (which you replaced already) and the wires being hooked up incorrectly.

I know you said you did it right, but check, just in case. Everyone makes stupid mistakes sometimes. The car will sometimes still run somewhat okay if they are in a different order.

Also the Crank Angle sensor (or Crank Position Sensor) I forgot which one....the one inside the distributer. Might be messed up, but you're not getting a code for it.

As a last resort, swap distributers with one of your friends for a moment and see if that's the problem.

 

bump... ever find out exactly what happend?

 

Not yet, Bro. It's too cold in Minnesota to be working on stuff. I'm going to try to exchange the plug wires for some new ones, but I'm starting to think it's the distributor.

 

my cars been acting weird too.. like i put some fuel injector cleaner in it and it was bogging when i started it up..

then last night i turned my car on.. and reved it up to 3 (cuz it was cold and wanted to get the engine started) and it just shut off, then i couldnt crank it over.. i tried about 4-5 times and then all the sudden it worked... i have no idea whats going on..

im getting ready to sell the peice of **** and get my wrx

 

can you feel the missfire or is it intermittant? it is very unlikely that you crossed wires without noticing some major drivability problems. the car probably would be struggling to run. did the light come on immediately after you threw in the plugs and wires? if so i would suspect that you gapped the plugs wrong, got a bad wire or didnt put the wire all the way on the plug or cap. its OBD2 so you will get cylinder specific codes. If you can get youre hands on a scan tool and get cylinder specific codes. PO300 being random missfire, PO301 being missfire cylinder 1, PO302 being cylinder 2 etc. That should help you narrow down youre search. Another quick way to spot an ignition missfire would be an oscilloscope, but you would probably have to bring it into a shop for that. Most common causes for a missfire DTC- plugs, wires, cap, rotor, injector. good luck.

 

bayarea13-- I can't feel the misfire, and it doesn't seem to be underpowered. However the exhaust pulse ay idle just doesn't seem quiet right.

The codes I pulled (using the paper-clip/flashing-engine-light method) were cylinder specific. They were for Cyl 1 and Cyl 3--opposite-firing cylinders.

When I first did the tune-up, I noticed a plug wire connection was loose, so I put it back on. That wasn't it.

I swapped out the plug wires for some new ones from NAPA again. Then, I pulled the back-up fuse to reset the light... It came on again.

I'm starting to think it might be the plugs--probably the gap, because now that I think of it, I used a pretty crappy gapper tool that only had .045" instead of .044". It's not a huge difference, but it might be enough to do it, especially with a stock ignition.

I'm going to try to re-gap this weekend and pray. Otherwise I got a buddy at Honda who said he'd put it on his 'scope.

I could look at the bright side, too. If I can't get to the bottom of this, time for a swap! :!

 

i had taht exact code. i think its cylinder 1 misfire...check your plugs

 

what kind of plugs r u running

 

i had 71,72,74

went away when i did valve adjustment

 

allmotorteg_96-- I'm using the recommended NGK plugs, but I gapped them with a crappy gapper.

I'm going to try re-gapping them and see.

Dan GSR-- My buddy at Honda said to try adjusting the valves, too. He said if I don't and they need it, it could burn one out. That would suck. I think that even if the plugs work, I'm going to try this too... on all my cars!

 

Good news: Problem solved!

Bad news: Did more than one thing at once, so I don't know 100% which fixed the problem.

I adjusted the plug gap on all four plugs. Some were as high as .050"! Then, I adjusted the all the valves (I'm pretty sure this is what did it because they were WAY off!). After that, I just adjusted the ignition timing to stock (it was only off a few degrees, but I was on a role.)

Thanks, everyone, once again!

P.S. If you haven't done it for a while (or never), I'd adjust your valves for sure! This thing runs a billion times smoother and has noticably better pick-up.

 

valves
definitly the valve adjustment

i got the cel when i did the valve adjustment with the engine too hot

i redid it, and never came back