changed plugwires and runs horrible....

[rcantu]

hi guys,

i decided to change my wires because 2 of the rear connections to the coil had rust and didn't click on the coil so i decided to buy some new msd 8.5 wires. I felt there was possibly a little rpm miss when driving and i was chasing down why the car was shootin black smoke.

well i changed them 1 by 1 so i wouldn't mess up firing order. I cleaned the coil contacts and used dilectric grease. reset the ecm by unplugging the orange wire near the battery.

now when it starts and runs awful. it will sputter and almost die. when i tap the throttle, it starts to miss. revving it is just way off too. it even backfired or knocked on me.

i have a power logger and all the idle numbers seem to be within spec from gnttype.org quick reference guide. In fact the g/s numbers for the maf was better after i swapped wires. before it was at 9+ and now it's at 7.

my set up is stock motor, heads, turbo. TT chip, lt1 maf, translator (dip switches set up,up,up, down and base set at 0), tps-tec (set .42 volts), k&n cone filter, caspers heated o2 harness and new o2 sensor. fuel pressure at 43psi w vac line off.

i changed my vac lines to silicone beforehand. car was running rich before i changed wires but it never ran so horrible. Rechecked the wires and all seem secure.

it's pretty frustrating when trying to fix something and it gets worse.

i did some searching and it seems stock maf were some issues. you guys think my coilpack just went south on me? seems just like bad luck

any help is appreciated.

 

[Blazer406]

IMHO... you shouldn't have re-set the ECM. ..... for one... you lost any settings inside the chip that had been tweaked over the default.... and now the ECM has to re-learn all the BLM cells it has to tweak by itself.

Yes... it is possible to have a bad coilpack...and module... however this wouldn't likely occurr by just changing plug wires....

Can you determine if it is a dead miss or an intermittant miss?

You have obviously disturbed something that didn't want to be disturbed...

FWIW... AutoZone can test your coilpack and module combo for you..... and everything I read... says don't even think about buying anything other than AC Delco for a replacement module and coilpack....... as all others are pretty much hit and miss if you are going to get a good one....

 

[rcantu]

i think it's a dead miss cause it just runs so bad all the time now.

i wish i hadn't reset the ecu either. it was a dumb mistake

 

[Just a Six??]

Dont worry the computer relearns in a minute or two. The downside is the custom settings if you had any? I just write them down altho there arent many in my case. Either the wires are bad (long shot) or you disturbed something as mentioned. Do you get 11-13 ohms on the coilpac test? Not precise test but helps for a quick check.
Read at Vortex Turbo Buick Performance if you never been there before.

 

[rcantu]

i didnt have any custom settings. i just got the chip last week because i thought the current chip wasn't good. it actually helped too.

i haven't done the coilpack test. do you have a summary on how to do it? i have a dmm.

thanks for the link.

Dont worry the computer relearns in a minute or two. The downside is the custom settings if you had any? I just write them down altho there arent many in my case. Either the wires are bad (long shot) or you disturbed something as mentioned. Do you get 11-13 ohms on the coilpac test? Not precise test but helps for a quick check.
Read at Vortex Turbo Buick Performance if you never been there before.

 

[garyk1970]

doesnt hurt to double check

make 100% sure.......also try unplugging MAF then start ,to see if idle quality is better....

 

[whitehot1]

Just a couple of thoughts here.

Is there any pieces of the old plug wire terminals still on the coil towers? especially 1-5-3 the ones in back that are hard to see.

If that's not the problem do you still have the old wires? maybe you could reinstall them and see if that helps. Perhaps you got a set of bad (new)wires,like already mentioned.

None of the vacuum hoses got disconnected by accident did they? i know sometimes when working under the hood things get bumped,pressed or leaned on without being noticed.

The auto parts stores, some anyways can test the ignition module for you but i haven't found one that can or will test the coil pack.

hth, :smile:

 

[rcantu]

im gonna check the wires and make sure nothing broke off.

i think i'll swap back 1 wire at a time and see if it makes a difference and help me isolate if it's 1 bad wire.

thanks

 

[rcantu]

ok. Changed wires back and same prob. Checked vac lines and any loose wires. All look good. Still ran just as bad. Also unplugged maf and ran worse.

Here's one thing I noticed. It idles good for a few min then it starts stubling and shaking. I checked voltage and it dropped from 13.6 to 12.4 volts. I'm charging my battery as we speak. Do u guys think it's electrical? It's pretty frustrating.

 

[sweetv6]

check if you have fire on each coil pin

had a problem like that when i going out from storage

hop it help

cp

 

[garyk1970]

wiggle the orange ecm lead at the battery while the car is running and check for any changes in idle.......make sure battery terminals are clean/tight.
check ground at fender from battery.
wiggle the ecm and all fuses in fuse block while monitoring idle.
theres a ground on passenger rear head that gives problems too.

 

[rcantu]

check if you have fire on each coil pin


cp

how do you check that?

i'm gonna look at loose grounds right now

 

[whitehot1]

Did you do the ohm test on the coil pack?

It should read 11-13k ohms on each of the pair of towers 1-4 , 2-5, 3-6.

 

[rcantu]

ok. just did. 1-4 is 14ohm while 2-5 and 3-6 are 13 ohms.

you think that's the culprit?

i already wiggled the ecu orange wire and also looked at the fender and head ground. looks secure.

Did you do the ohm test on the coil pack?

It should read 11-13k ohms on each of the pair of towers 1-4 , 2-5, 3-6.

 

[rcantu]

soon as the car goes into closed loop it really idles low and is about to die. in fa ct it just did.

here's my PL screen shot

 

[whitehot1]

Do you have a spare coil pack to swap in?

Is that the original coil on there now?

 

[rcantu]

no spare.

its not original. its some "high voltage" coil pack the previous owner bought.

Do you have a spare coil pack to swap in?

Is that the original coil on there now?

 

[FreeBoost]

make 100% sure.......also try unplugging MAF then start ,to see if idle quality is better....

X2

 

[rcantu]

unplugging maf didn't do it.

X2

 

[whitehot1]

no spare.

its not original. its some "high voltage" coil pack the previous owner bought.

What state are you in?

Do you know any other turbo regal owners close by you that would let you maybe swap it out to see for sure that is the problem.

I think autozone has them for something like $45.00 and if you know someone who works there may let you return it if it's not the problem. But of course i'm not talking from experience here.