: horrible surging



Dubya
03-17-04, 03:05 AM
ive had this problem for about a week, at first i thought it was a bad tank of gas, then i noticed i could hear a clicking, so immediatly i knew a spark plug boot popped out of its hole (just got a car wash with undercarriage wash). 1 was off, it was the back middle one. i could swear it drove fine after i did that, but i only drove it for 4 minutes, then the next day the problems were back. no more 'clicking" and no spark plug wires are loose.


i then thought i had a bad tank of gas, which has happened before, so i waited till i was out, filled up and its definatly not a bad tank of gas. seems like its not AS bad when its cold, but gets worse when it warms up. the car is SLOWWWWW at all speeds, horrible surging at light to mid throttle. under wot it surges some, but its just slow in general not very much pickup. at idle it goes from 600 to 950 back to 600 all over the place.


here's somthing else i noticed. when i grab a spark plug wire, the front 4, if i grab the two in the middle i can FEEL a pulse going through the plug wire, its a pretty good pulse too, easy to notice. but the two on the end, when i grab them i don't feel anything, could it be a bad coil pack? i havn't tried the back 4, i have to take off the coil packs to get at those

Ralph
03-17-04, 03:15 AM
Im no expert, but what comes to mind are a restricted exhaust system? Air filter and intake system? Fuel pump acting up? Fuel filter clogged? Low engine compression? Maybe the brakes are dragging, but I doubt it? My Chiltons says oil overfill might cause this! You might be right about the coil, but I'm trying to figure out the clicking! Probably fuel system.

Dubya
03-17-04, 01:33 PM
the clicking is gone, it was from a loose spark plug wire (it was arching)

Lawrence
03-17-04, 02:05 PM
I have felt this before. I my case the cylinder was not firing and you could feel it in the wire. Get a spark gap tester and test those two cylinders. Check for arching in those wires. Check for corrosion at the coils. And/Or just replace the plugs and wires on those cylinders.

BeelzeBob
03-17-04, 04:05 PM
the clicking is gone, it was from a loose spark plug wire (it was arching)

Sooo....does this mean things are back to normal and the engine is running fine...or is it still acting up and just doesn't click anymore.....

Dubya
03-18-04, 02:17 AM
the clicking is gone, but it still drives like crap, horrible. i can feel the pulsating on the front two spark plug wires, havn't checked the back (working all day).

someone suggested that maybe because that one was arching for a while, it could have damaged a coil....but the one that was arching is NOT one of the two in the front middle that are doing the pullsating, almost like a hose with large amounts of water pushing through

Dubya
03-18-04, 02:38 PM
how do i trouble shoot to find out which coil/wire/plug is the bad one?

its idle is so off beat, i don't notice when i pull a a good spark plug wire

can i damage anything by pulling a wire while its running?

and lastly, is it worth the extra $50 to by ac delco spark plug wires over autolites? ($70 vs $120)

ugh!!

thanks

Dubya
03-18-04, 06:56 PM
one of the coil ends was corroded really bad, the one that wasn't connected after the car wash, so i cleaned that off with steel wool, and got some spark plug wires, and its purring like a kitten. i feel kinda dumb saying this, but it does seem a little torquier, little more get up than before. maybe its just in my head, maybe because the oem wires had 138k on them, who knows.

oddly enough, that pulsing through the wires, is still there on 1 of them in the front middle, maybe its nothing, i dunno


thanks for the help

Dubya
03-18-04, 11:01 PM
ok now im confused, confused and mad. i drove for about 45 minutes, no problems, then i got a surge, shrugged it off. then i got a few more, light surges. hmmmm the later the night, the worse they got. under wot i get a few (4ish) up to about 55 now. so yeah, its back but not as bad as before, yet

what gives??

i pop the hood, i think i hear clicks (like the spark plug loose clicks) but there fainter than before, and definatly in the back. i get home, check them all, all tight. restart, idles fine (for now) but i don't drive it anywhere. brand new autolite spark plug wires - they seemed to help, for a while.

jeez

Lawrence
03-18-04, 11:23 PM
Did you remove the coil pack?
If so did your re-attach the ground wire from the head to the coil pack?

Could be that coil that had coroded tip is bad. Check it first. Then check the two front ones you could "feel". You need to get a spark tester. They are only a few bucks. A clear plastic tube with two spaced terminals inside that allow you to see the spark make the gap. One end goes to the spark plug and the other to the wire or coil. That will tell you if your coils are bad or not. Leave it on awile, let the engine get to normal temp and briskyly run the engine through its rpm range (within reason). If you see it miss any beats its bad.

Dubya
03-19-04, 04:31 PM
ok, well i took the spark plug wire off the coil again, the same one that was causing problems before, it was brown from arching again, not as bad, yet

so i bought a new coil, the old guy there said once the insulation goes they start to arch and you just need a new one. so far, so good, ill post if anything changes :D

thanks for the help

Dubya
03-21-04, 11:12 PM
ok, so here's a little weekend recap. after i cleaned the coil tip it ran great, then it started to surge again, only to find out that the tip was a little burnt again. so you might be thinking, simple fix, just replace the coil. well i did that, ran great for 3 hours or so (alot of driving friday) then it slowly started to come back, and its back again really bad. so i take a look at the coil tip, looks fine. im starting to get upset here! im 99% sure its NOT the fpr, its a stumble/surge at all speeds, but the engine rocks back and forth at idle in gear (not so much in park) so this makes me believe its a cylinder not firing. so the search continues....i did find a complete set of coilpacks on ebay, off a brand new northstar engine (new reclaimed) which would run me $120-$135) but i replaced the coil already, some off name brand though.....ugh i dunno. spark plugs next? i don't get why it would run great then like crap. i ordered the ac delco platinum spark plugs off rockauto.com, they'll be here in a few days i guess, NO ONE carries ac delco except the dealers, and they charge about $12 a plug, i got them for 5.40. im considering buying this new reclaimed coilpacks off ebay, wish i didn't just spend $45 on one at checkers though..... and they say i cant return ignition parts once they've been used, but it may be deffective.

Dubya
03-24-04, 12:15 AM
found out my problem, permanantly. so it was running fine, then all of the sudden, crap again. check everything, seems ok. but that one spark plug wire that blew out on the car wash, just wouldn't "click" into place, i had to push H A R D to get it to snap in, and it barely went in. so i think whats happenening, is its just popping out every so often. (which is odd because that coil really did have a bad coil too)


anyone ever have this problem? how can i fix it? i already have new spark plugs comming, ordered them so i might as well put them in even though the ones in there are probably good. i don't know how i can make it seat any better, i already tossed the oem wires, but they seemed to have the same problem on #5

BeelzeBob
03-24-04, 12:45 AM
found out my problem, permanantly. so it was running fine, then all of the sudden, crap again. check everything, seems ok. but that one spark plug wire that blew out on the car wash, just wouldn't "click" into place, i had to push H A R D to get it to snap in, and it barely went in. so i think whats happenening, is its just popping out every so often. (which is odd because that coil really did have a bad coil too)


anyone ever have this problem? how can i fix it? i already have new spark plugs comming, ordered them so i might as well put them in even though the ones in there are probably good. i don't know how i can make it seat any better, i already tossed the oem wires, but they seemed to have the same problem on #5

Sometimes the little "umbrella" on the plug boot will seat against the cam cover and pull the plug boot up over time. The cure is to either swedge the terminal inside the boot tighter so it grips the terminal of the spark plug tighter or just trim the umbrella on the plug boot so that it goes inside of the spark plug well in the cam cover.....you can usually just trim a little off the perimeter of the umbrella with scissors so that it slides down inside of the spark plug well. The other thing to check is to see if you can work the plug wire further thru the boot so that the terminal at the end of the wire is further down the plug boot...so that it clips onto the plug terminal before the umbrella seats and starts to pull the boot upward.

1993 eldorado green1
04-06-04, 02:20 AM
if that wasnt the problem, i had a 1994 eldorado that did that and it was my alternator causing voltage surges continously in a sort of a pattern, we installed a new one and she runs great, the rebuilder tested my old alternator and it was producing voltage from 8 volts to 21 volts in a rapid pattern,, just a thought.

KrazyK55
04-06-04, 07:32 AM
Hi Guys,

I've been battling a similar problem with my 96 Eldorado but my stumble, surge or misfire isn't constant and is limited to the #1 cylinder according to my Accu-tron trouble code scanner.

I've tried everything that you have with no success and my next step is to change the coils within the pack and see if the misfire moves with the coil.

Please let me know if you figure out the problem and I'll do the same. If anyone is interested, I have listed a sight below that is a good source for GM parts at reasonable prices. I've made several purchases from them and been very satisfied with their money saving prices and quick service.

Good Luck!

Dave

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OlManRivah
04-07-04, 12:16 AM
Am I reading correctly that this all started after a car wash (under carriage type)? Possibly high density water got under hood from beneath and got an electrical connector, old wires, etc. wet and corrosion setting in.

If this is case a complete visual inspection.