Help 3787's problem?
#1
Member
Thread Starter
Join Date: 06-28-09
Location: PA
Posts: 278
Likes: 0
Received 0 Likes
on
0 Posts
Help 3787's problem?
I installed the ngk 3787's Friday morning and put about 50 miles on them. Tonight i was out cruising around and under light acceleration in 4th/ just cruising at 40mph the car started to miss and cut out. It was fully warmed up. I was only about 4 miles from home so i drove it home very easily no boost etc. When i pulled into drive and parked i let it idle and it held idle smooth like before. Im puzzled because no CEL came on or flashed at all during the missing/cutting out. I did rinse my engine bay down with water today but that was 6 hours before and the missing started well after fully warmed up. Im gonna put stock plugs back in tom when the engine is cold. Any ideas whats happening? Every time it would miss/cutout it would whistle like when letting off the gas but i didn't let off the gas, maybe its another problem not plugs? Any help is much appreciated.
#3
Senior Member
iTrader: (10)
Water evaporated when the engine got hot & moisture got into some wiring or the coil packs maybe? I doubt it's the plugs though. See how it runs after it sits all night and dries out.
When I wash the engine bay, I blow all the water out with compressed air & let it dry overnight in the garage with the hood up. I've been running the 3787's around 2k miles now but I boost a bit.
When I wash the engine bay, I blow all the water out with compressed air & let it dry overnight in the garage with the hood up. I've been running the 3787's around 2k miles now but I boost a bit.
#4
Member
Thread Starter
Join Date: 06-28-09
Location: PA
Posts: 278
Likes: 0
Received 0 Likes
on
0 Posts
Alright, how long must you let the engine cool down before a plug swap, if id drive it tom morning to see and it still does it how long till you know its cool enough to pull the plugs? I do have stage1 but no tune on top. Shouldn't a CEL came on w/e it was? And it happened after about 30 min of driving around, Highway/around town and i rinsed the engine bay around 1 and this occurred around 7.
#9
Senior Member
iTrader: (2)
Join Date: 09-24-09
Location: Fort Bragg, NC
Posts: 1,303
Likes: 0
Received 0 Likes
on
0 Posts
Makes no sense to me about the NGK plugs. I been running DensoTT for about 100 miles so far and haven't experience any problems. I made sure the gap was the recommendation at .40 before I put all 4 in and so far they have run smooth. No CEL or anything. I think it could be the gaps on your spark plugs that may have caused the issue in the first place or they aren't really cut out to run in the motor.
#10
Member
Thread Starter
Join Date: 06-28-09
Location: PA
Posts: 278
Likes: 0
Received 0 Likes
on
0 Posts
Stock plugs are gapped about .31 and thats what the ngk 3787's come as, i checked them before i put them in and no i didn't ruin them by opening the gap up etc, becuase i didn't need to open any of the gaps. The plugs you have gapped at .40 seems quite big
#11
Senior Member
iTrader: (2)
Join Date: 09-24-09
Location: Fort Bragg, NC
Posts: 1,303
Likes: 0
Received 0 Likes
on
0 Posts
if you see a double tip spark plug, you wonder why I never once gapped it. I made sure it was at .40 with my gap meter before I threw them in the motor. the only thing that got my attention was the huge spark it created and the benefits I would get out of it.
here is the site to check out http://densott.com/
here is the site to check out http://densott.com/
Last edited by efactor; 04-04-2010 at 08:51 PM. Reason: Automerged Doublepost
#12
Senior Member
Join Date: 09-04-09
Location: Alabama
Posts: 2,218
Likes: 0
Received 0 Likes
on
0 Posts
I've had no problems out of the 3787's since I installed them about 2 months ago. I used the .031-.032 gap setting they came with, the only other thing I did was put some die electric grease in each boot.
#13
I have the 3787s too for about 2 months now and haven't had any issues. These are 1 step colder plugs and from what I have always been told, unless your car is 70-100hp over stock you shouldnt be using any step colder plug.
for every 70-100hp added over stock = go one step colder on plugs
a stage 1 fom gm only adds 20hp over stock.
for every 70-100hp added over stock = go one step colder on plugs
a stage 1 fom gm only adds 20hp over stock.
#14
Senior Member
iTrader: (1)
I have the 3787s too for about 2 months now and haven't had any issues. These are 1 step colder plugs and from what I have always been told, unless your car is 70-100hp over stock you shouldnt be using any step colder plug.
for every 70-100hp added over stock = go one step colder on plugs
a stage 1 fom gm only adds 20hp over stock.
for every 70-100hp added over stock = go one step colder on plugs
a stage 1 fom gm only adds 20hp over stock.
#15
Member
Thread Starter
Join Date: 06-28-09
Location: PA
Posts: 278
Likes: 0
Received 0 Likes
on
0 Posts
Well switching the plugs back did not fix the problem. It Started doing it again today after about 30-45 min of driving. No cel at all just missing and hesitation under light accleration and cruising. Any ideas what it might be??? I called the dealer and they sadi to call back when service people are in tom. I don't understand why theres no cel light. Im afraid the dealer will say it didn't duplicate the problem etc.
Thread
Thread Starter
Forum
Replies
Last Post