383 backfire/hesitation issue
07-12-2010, 12:44 AM
#1
Staging Lane
Thread Starter
Join Date: Oct 2009
Location: Madison WI
Posts: 54
Likes: 0
Received 0 Likes
on
0 Posts
383 backfire/hesitation issue hey, so I have kind of a weird issue. I read up on all the common opti symptoms and I'm not sure that mine fits in there.
Background - Just put this 93 383 into my 94 this spring and have about 5000 miles on it...about 1500 miles ago the SES light started coming on when I got up to highway speeds (it would NEVER come on if i didn't go about ~45) so I tried to get the codes but it never worked and i just got an error. I talked to someone about it and was told it was prolly something to do with the AIR delete (not sure).
Also, since the motor swap @ WOT there is a ton of black smoke...assuming I am running rich, I am hooking up a wide band to check A/F and then get a good tune.
Problem - So now, the first time I start my car in the day it will run perfect. No stalls, idle is good and it pulls w/o hesitation all the way through. I can drive it for 3 hours in the city and on the highway w/o any problems. Once I shut the car off and let it sit for about an hour and start it back up, all hell breaks loose. It dies at stop lights, backfires under load and the idle varies from 900-1100 rpms.
So with this being a new problem, so far I have only changed the plugs and wires. After looking, the water pump is leaking for sure (onto the opti obviously) and that seems to be the only leak I have and that is being replaced. I just don't understand how it can work perfect and then once it sits it breaks.
I want to get the car tuned within a few weeks but I need it to be running good for that. I understand that its hard to diagnose an untuned car, but I just want some input for ideas on where to start to fix/find this issue.
Thanks in advance and I'm sure I have forgetting important information that you guys need to help me so just ask and I will do my best to answer it.
GM847 Cam, Eagle Crank, Eagle Rods, SRP Forged Pistons, 1.6 Roller Rockers, Comp Srings, 42lb Injectors, LPE CAI, Full Exhaust, PCM tune
Background - Just put this 93 383 into my 94 this spring and have about 5000 miles on it...about 1500 miles ago the SES light started coming on when I got up to highway speeds (it would NEVER come on if i didn't go about ~45) so I tried to get the codes but it never worked and i just got an error. I talked to someone about it and was told it was prolly something to do with the AIR delete (not sure).
Also, since the motor swap @ WOT there is a ton of black smoke...assuming I am running rich, I am hooking up a wide band to check A/F and then get a good tune.
Problem - So now, the first time I start my car in the day it will run perfect. No stalls, idle is good and it pulls w/o hesitation all the way through. I can drive it for 3 hours in the city and on the highway w/o any problems. Once I shut the car off and let it sit for about an hour and start it back up, all hell breaks loose. It dies at stop lights, backfires under load and the idle varies from 900-1100 rpms.
So with this being a new problem, so far I have only changed the plugs and wires. After looking, the water pump is leaking for sure (onto the opti obviously) and that seems to be the only leak I have and that is being replaced. I just don't understand how it can work perfect and then once it sits it breaks.
I want to get the car tuned within a few weeks but I need it to be running good for that. I understand that its hard to diagnose an untuned car, but I just want some input for ideas on where to start to fix/find this issue.
Thanks in advance and I'm sure I have forgetting important information that you guys need to help me so just ask and I will do my best to answer it.
GM847 Cam, Eagle Crank, Eagle Rods, SRP Forged Pistons, 1.6 Roller Rockers, Comp Srings, 42lb Injectors, LPE CAI, Full Exhaust, PCM tune
07-12-2010, 01:03 AM
#2
TECH Enthusiast
Join Date: Jul 2008
Location: Miles City Mt
Posts: 734
Likes: 0
Received 0 Likes
on
0 Posts
Could be that after it sits for a long while and fluids that leak onto your Opti are having a chance to dry out. But after your car is up to operating temperature and fluids are circulating. Once you shut it off and fluids leak onto the Opti again. There isn't enough time for it to evaporate so once you come back an hour later Opti is not working right. Not sure if I made any sense I am tired as hell its been a long day
07-12-2010, 01:53 AM
#3
Staging Lane
Thread Starter
Join Date: Oct 2009
Location: Madison WI
Posts: 54
Likes: 0
Received 0 Likes
on
0 Posts
thats seems legit. I have the vented opti so I guess that could explain why it drys out and works.
For whatever reason, I have always been under the impression that once an opti is wet, its done for
For whatever reason, I have always been under the impression that once an opti is wet, its done for
07-12-2010, 05:55 PM
#4
TECH Enthusiast
Join Date: Jul 2008
Location: Miles City Mt
Posts: 734
Likes: 0
Received 0 Likes
on
0 Posts
Like any electronic I am sure it depends on how wet it gets and if it causes anything to short out. My daughter dumped a **** ton of water on my 4k gaming computer I built myself but lucky for me it was off. Took everything apart let it dry for a couple of days and put her back together. Everything ran fine.
