94 LT-1 problems
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,466
Likes: 41
From: Auburn MA
94 LT-1 problems
I have a 94 LT-1 6 speed coupe and this weekend I swapped out the old water pump, new intake gasket, and While I had the Throttle body off I gave it a mild port job using a dremmel and fine sandpaper. After I had it all buttoned up I ran it for a little bit and the car exhibited some odd behavior.
* upon first start up it Idled very high for a second 2,500-3,000 RPMs.
* it would drop down to 1,000 RPMs then eventually race up to 1,500 RPMs.
* i notice the EGR is leaking a little causeing whirrling noise under the hood and I believe that is the gasket causing the problem on that one (since I had to reuse the old one).
And NOW a week after the Install I crank the car and it wont start then when I stop cranking it "Deisels" and shoots smoke out (that smells like unburned gasoline) of the air cleaner.
What could be wrong Is my Opti junk.
* upon first start up it Idled very high for a second 2,500-3,000 RPMs.
* it would drop down to 1,000 RPMs then eventually race up to 1,500 RPMs.
* i notice the EGR is leaking a little causeing whirrling noise under the hood and I believe that is the gasket causing the problem on that one (since I had to reuse the old one).
And NOW a week after the Install I crank the car and it wont start then when I stop cranking it "Deisels" and shoots smoke out (that smells like unburned gasoline) of the air cleaner.
What could be wrong Is my Opti junk.
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,466
Likes: 41
From: Auburn MA
i was carefull and i tried to keep as much as i could off the opti but some did get on the side or around it.... i fear its my opti as well. but is this deiseling a common problem that diagnoses an opti problem.... because i havent ever seen this on a fuel injected car
Drifting
Joined: Nov 2005
Posts: 1,324
Likes: 5
From: Charlotte NC
Have you checked your fuel pressure yet? You may want to check that to see if you've got leaking injectors. Check also the seal around your MAP sensor. It could be easy to flatten one side of that seal which would let atmosphere in.
You really need to see if any codes have posted as well.
Thinking about the surging when you first started her back up, I'm guessing you had the negative terminal off of the battery and your engine was simply 're-learning'. Mine will do that when the ECM has been reset.
You really need to see if any codes have posted as well.
Thinking about the surging when you first started her back up, I'm guessing you had the negative terminal off of the battery and your engine was simply 're-learning'. Mine will do that when the ECM has been reset.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
Doesn’t really sound like an opti. If installed wrong it probably would not have started initially. A little coolant on the opti is not going to hurt it unless you gave it a bath.
Just wondering if you removed the IAC before you dremmeled the throttle body. Make sure there is no junk in it and it is clean. I would remove it and take a good look. Make sure the “O” ring is there and in good shape.
It sounds like you have more going on than just a re-learning process. Check some of the basics like fuel pressure and spark quality. Make sure all connectors that were removed are connected correctly and dry. Check to make sure there is no debris in the throttle body, I would blow it all out. You might also clean the MAF wires while you have it apart.
Just wondering if you removed the IAC before you dremmeled the throttle body. Make sure there is no junk in it and it is clean. I would remove it and take a good look. Make sure the “O” ring is there and in good shape.
It sounds like you have more going on than just a re-learning process. Check some of the basics like fuel pressure and spark quality. Make sure all connectors that were removed are connected correctly and dry. Check to make sure there is no debris in the throttle body, I would blow it all out. You might also clean the MAF wires while you have it apart.
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,466
Likes: 41
From: Auburn MA
Doesn?t really sound like an opti. If installed wrong it probably would not have started initially. A little coolant on the opti is not going to hurt it unless you gave it a bath.
Just wondering if you removed the IAC before you dremmeled the throttle body. Make sure there is no junk in it and it is clean. I would remove it and take a good look. Make sure the ?O? ring is there and in good shape.
It sounds like you have more going on than just a re-learning process. Check some of the basics like fuel pressure and spark quality. Make sure all connectors that were removed are connected correctly and dry. Check to make sure there is no debris in the throttle body, I would blow it all out. You might also clean the MAF wires while you have it apart.
Just wondering if you removed the IAC before you dremmeled the throttle body. Make sure there is no junk in it and it is clean. I would remove it and take a good look. Make sure the ?O? ring is there and in good shape.
It sounds like you have more going on than just a re-learning process. Check some of the basics like fuel pressure and spark quality. Make sure all connectors that were removed are connected correctly and dry. Check to make sure there is no debris in the throttle body, I would blow it all out. You might also clean the MAF wires while you have it apart.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
The IAC (idle air control) is a small stepper motor, fits in your hand is mounted near the front of the throttle body on the right side. It is held in by 2 torque screws and pull right out, take off electrical connector. Look in the area where it mounts and seats for any dirty or filings in it. The IAC plunger moves back and forth on a screw. There is mixed feelings about cleaning them out but if there is junk in it at least air blast it. Maybe a de-greaser, that would be your call depending on what it looked like.
There is no real simple test for them. Some times you can lube them but I have had no real luck with them over the years. If I suspect their bad I just replace it.
There is no real simple test for them. Some times you can lube them but I have had no real luck with them over the years. If I suspect their bad I just replace it.
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,466
Likes: 41
From: Auburn MA
well the wierdest thing happened.... It fired right up no problems at all. except for now a Low Coolant light when there is actually too much coolant in it and an occasional high idle and what seems like an EGR leak. that I stated above.
I did nothing to the car to fix it all it did was sit in my garage on a trickle charger to recharge the weak battery (that was drained from cranking it)
How do I reset the Low Coolant light on the D.I.C.
I did nothing to the car to fix it all it did was sit in my garage on a trickle charger to recharge the weak battery (that was drained from cranking it)
How do I reset the Low Coolant light on the D.I.C.
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Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
Sounds like the opti got wet and needed so time to dry out. As far as the low coolant light, perhaps disconnecting the neg. battery cable for a couple of minutes will reset it. There may also be a chance you have some air in the system?
Melting Slicks
Joined: Feb 2005
Posts: 2,135
Likes: 0
From: Sebastian Florida
St. Jude Donor '06
Low coolant light on when coolant is full, usually means you broke the sensor or the sensor is not connected properly.
Take out the IAC and I will bet money you have shavings in there.
Get pipe cleaners and stick it up through the TB and then spray TB cleaner on it and the TB to clean out, then work the pipe cleaner in and out a few times(might have to use 2 or 3 pipe cleaners).
By pipe cleaner, I mean the kind used to clean a tobacco pipe.
Take out the IAC and I will bet money you have shavings in there.
Get pipe cleaners and stick it up through the TB and then spray TB cleaner on it and the TB to clean out, then work the pipe cleaner in and out a few times(might have to use 2 or 3 pipe cleaners).
By pipe cleaner, I mean the kind used to clean a tobacco pipe.
Thread Starter
Melting Slicks
Joined: Feb 2005
Posts: 3,466
Likes: 41
From: Auburn MA
the wierd thing i noticed today when i took it for a ride was the digi coolant temp said 160degrees when the analog gauge was pegged out at over 260+ i am confused what could be going on mixed messages on the two differnt coolant monitering temps and the low coolant light when there is actually too much coolant in the system
Racer
Joined: Jun 2006
Posts: 408
Likes: 0
From: Elkton MD
High temp
After refilling the coolant in an LT-1, it requires 3+ temperature cycles to get all of the air out and stabilize the running temperatures. Especially the analog reading. This is even after bleeding all air possible from the bleed screws. The temp must be cycled from 'room temp' to fully warmed several times while 'avoiding aggressive maneuvers' according the the service manual.
My personal experience was that the analog temp was all over the place (requiring shut down during the first two temp cycles) especially on the analog gauge.
Regarding the 'diesel' action, a leak in the EGR will cause some strange misfiring, including running after. An EGR leak could also prevent the IAC from controlling the idle air volume correctly.
Hope this helps.
My personal experience was that the analog temp was all over the place (requiring shut down during the first two temp cycles) especially on the analog gauge.
Regarding the 'diesel' action, a leak in the EGR will cause some strange misfiring, including running after. An EGR leak could also prevent the IAC from controlling the idle air volume correctly.
Hope this helps.
