LT1 Surges when warm
#1
Registered User
Thread Starter
Join Date: Jan 2016
Location: Corvallis, OR
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
LT1 Surges when warm
Hi everyone. I have been struggling with this issue for about a week now. When I first drive in the morning, the car runs perfectly. As soon as it warms up, however, the idle surges at a stop and the acceleration is jerky and feels much less powerful. This issue lasts the whole day. Even after the car sits for four hours while I'm at work the issue starts the second I fire it back up. I have fixed a few minor vacuum leaks and replaced the fuel filter. This issue never happened on my old distributor. I put a new MSD billet distributor in it last week and it ran like a top for about five days until this issue began. Any ideas would be greatly appreciated.
#2
Registered User
Thread Starter
Join Date: Jan 2016
Location: Corvallis, OR
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
Just a quick update and some more details I forgot. I have cleaned the MAF and it did not change anything. Today after class I started it up and it ran awful. It bucked and barely accelerated and was backfiring. After a few minutes driving it smoothed out and the surging was barely noticeable. This was after sitting for about three hours.
#3
TECH Addict
Just a quick update and some more details I forgot. I have cleaned the MAF and it did not change anything. Today after class I started it up and it ran awful. It bucked and barely accelerated and was backfiring. After a few minutes driving it smoothed out and the surging was barely noticeable. This was after sitting for about three hours.
#5
Registered User
Thread Starter
Join Date: Jan 2016
Location: Corvallis, OR
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
I have not done the spacer mod yet. That is on my list for Saturday when I have a chance to work on it during the day. And yes it still has EGR. I pushed the diaphragm while the engine was running and it almost stalled so I took that as the EGR working.
#6
TECH Addict
iTrader: (1)
2 most common types of problems that arise when a car reaches operating temps are either faulty ignition components (failing electronics will show more issues when faced with higher heat) and sensors that only read during closed loop (i.e. o2 sensors).
Since the issue came after the msd unit was installed, I would replace it with an oem unit.
Since the issue came after the msd unit was installed, I would replace it with an oem unit.
Trending Topics
#10
TECH Addict
#12
Registered User
Thread Starter
Join Date: Jan 2016
Location: Corvallis, OR
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
Here's a video I just took of the car at idle. The coolant was just under 160 according to the gauge and the car had been sitting for about three hours. This is right after startup. I never once touched the throttle.
#13
TECH Addict
Here's a video I just took of the car at idle. The coolant was just under 160 according to the gauge and the car had been sitting for about three hours. This is right after startup. I never once touched the throttle.
1996 Z28 LT1 idle issue. - YouTube
1996 Z28 LT1 idle issue. - YouTube
Did you get just the cap and rotor or the whole opti from MSD?
I'd still try the ICM spacer mod though. They get hot all on their own, add in head heat and it can get messed up. And they are super easy to do.
#16
TECH Resident
I'd try a quality set of plugs and wires first if it feels like a miss when driving it.
Before doing that, make sure all the wires are seated tight on the plugs, opti, and coil just to rule out a loose wire. Double check any wiring harness you touched during the install as well.
Just because I don't know...question to the forum.....Do the MSD units still have trouble with the screws backing out of the rotor?
Also might not hurt to make sure that the screw that adjusts the timing on the MSD unit is still tight(and set at 0...at least I think it's 0). I'm assuming they still have that adjustment.
Before doing that, make sure all the wires are seated tight on the plugs, opti, and coil just to rule out a loose wire. Double check any wiring harness you touched during the install as well.
Just because I don't know...question to the forum.....Do the MSD units still have trouble with the screws backing out of the rotor?
Also might not hurt to make sure that the screw that adjusts the timing on the MSD unit is still tight(and set at 0...at least I think it's 0). I'm assuming they still have that adjustment.