I am a new Camaro owner and new to ls1tech.

I just bought the car 3 weeks ago from an older lady. I am the second owner. I am having some issues and would like advice from more Fbody owners. I have been trying to research for the last few weeks with no solid answer. the issue i am having is the car will start out great while sittinf for a few hours. Once it hits normal op temp or 3-5 milutes of driving it will start sputtering bad and not move hardly. I was told once it goes from open and a clsed circuit it starts the sputtering.


Little car info:

1994 LT1 camaro A4
173,200 miles
100% stock

I have taken the car to chevy and pulled the following three codes:
48- MAF sensor circuit,52- Ignition control kit, and 50- volt low.



When I first bought the car i have replaced the spark plugs, fuel filter, knock sensor and oil change.

The pervious owner has said to have replced the o2 sensors(3 years ago), egr valve(1 year ago), and plugs( 5 years ago).

I have been told to check the Coil, Control module, and opti-spark.

I pulled the wire from the coil and seen it sparking, and when I unclip the control mod it will start but throw a SES and I have been told that the car will not make it past 10-20 miles if the opti was bad.

So far I have ruled out the coil,control mod, and opti.

Ive also had the car running, and unplugged the MAF and the car did not die or throw a SES.


Would anyone be able to steer me in the right direction?



Thanks for your help.


UPDATE:

This weekend I replaced:

MAF sensor, ICM, and coil. I had help from a fellow camaroz28 send me his extra ICm's, and MAf sensors..

The extra parts didnt change anything. When i bought a new coil the rough idle went away and had little to no hessitaion.. Until i took the car out today and its acting the same way. as before the new coil..

what else should i be checking or replacing?

thanks

 

Shoebox has excellent information on his page...I would check fuel pressure,icm,coil,opti spark harness,and the opti itself also could be a bad temp sensor in the water pump...Welcome to the wonderful world of owning an LT1..

 

You already posted this and got responses. Generally, its a better idea to continue the original thread, so people know what had already been suggested, and what your repsonses were.

https://www.camaroz28.com/forums/sho...d.php?t=807497

You indicate 3 codes:

DTC 48 - MAF sensor. When you unplugged the sensor, did the engine run better?

DTC 50 - Low system voltage. What voltage is your dash voltage gauge indicating?

DTC 52 - That code is not used for the LT1.

Do you possilby mean DTC 42? That could be a problem with the IC module. Seeing a spark doesn't prove its OK under all conditions. The problem may be heat soak, which would cause the ICM to break down as it heats up. The ICM should be tested under high heat conditions.

What did you do in response to the comments about the problem being related to the transition from open loop (cold start) to closed loop A/F ratio control (engine fully warmed up, O2 sensors hot and working)? That often points to a problem with the O2 sensors, or something that affects the O2 sensor readings.

Not sure what you mean by "I have been told that the car will not make it past 10-20 miles if the opti was bad." If the optical cam position module in the Opti is failing due to heat soak, it might continue to run - just run poorly. The fact that it runs for more than 10-20 miles does not rule out the Opti.

 

^^
I Forgot I made a post already on this site.

Yes, I ment to type Dtc 42.


The volt code came up because I forgot to clip the alternator harness back on when I did my plugs.

I was told by another owner that the opti wouldnt go more than 10-20 miles if it was bad.


I have been told by other owners with 'same' problems.

One owner changed o2 and knock sensor and fixed issue

Other has banged coil and plugs.

And another owner replaced opti, coil, icm, wires, knock sensor.


When I unplugged the maf the car seems to idle higher and Apper to sound better buy driveability was the same.

If the icm is failing while under the closed loop.

Would I be able to relocate the icm?

Fill the hole that the icm sits on?

I've read some users put isolation around the part and helps cool it down

 

Shoebox has a suggestion for the IC module:

http://shbox.com/1/4th_gen_tech2.html#ICM_cooling

Putting insulation around the ICM will not cool it down. The module sits on an aluminum plate that is a heat sink, with heat transfer compound between the ICM and the plate. The problem is the heat sink can't pull heat out of the ICM because it's up against the hot head.

If you want to believe the Opti will only go 10-20 miles if its bad, that's up to you. I can only tell you that's wrong.

If the knock sensor was faulty, you would have had DTC 43. Not likely to cause it to "start sputtering bad and not move hardly.". Stop replacing parts at random - you are wasting your money.

What does "Other has banged coil and plugs"....... banged the coil and plugs???

PS:

This is CamaroZ28.com

Guess you copied and pasted from another site.

 

Sorry, I don't have a computer and hard to edit a post while using an iPhone.

I ment to say CHANGED not banged.

Like I said, I am a new owner and I have several people feeling me what fixed their problem. So yes, I did waste 32.00 on a knock sensor. But afterthat I refuse to buy any thing else until I find a solid answer to the issue.


Since the maf and icm came up. Im going to find someone with a spare of each and swap them out to resolve the issue.

 

check voltage going to and from the icm and meter so you verify good connections..

 

i had the exact same problem when i first bought my Lt1 and it turned out to be the OPTI. It was fine for about 10 minutes once it warmed up it ran like crap i drove it about 200 miles so you can drive it if the OPTI is not working right and on the highway it felt much better than in town. hope this info helps sounds a lot like the same problem i had.

 

How do I check the voltage?

I have an ohm meter. I will search here and google on how to test the mad, and icm.

 

Updated my first post please read.
Thanks