I finished removing the old Delteq system that came with my car (see "irratic engine" and "putting on coil wire," threads for more bacground) and restored the coil, sparkplug wires to original etc. Started right up. Got license back on and drove it to work the last two days and ran fine. Yesterday when I got home I checked to see if I had any codes present, but all was well. The only problem I have is my mileage on the computer is about 19-22. This morning when I came in I also noticed my engine temp and oil temp seemed low after driving the 38 miles to work. Both gauges were showing around 150-155 degree's. Should I be getting an error code from temp sensor if it was not working right? I read one thread saying that on a '90 C4 that engine running cold would use more fuel. So what should I be checking for. I see the book mentioned about checking throttle body. Oh yes, this has the fuel from last fall 5 months old in it yet with stabilt in it. Perhaps wait till that gets cleaned out better or look at something else. Sure a big improvement from when I picked it up last Sept. It had a new opti, water pump installed about 5000 miles ago at 76,000 miles. It has about 81,000 now as it had 79300 when I picked it up. My goal is to get 28mpg. Friend at work has a '93 and he will get30-34+ on the hwy. And others have said they get 28-30+ hwy.

Also thanks to those who made suggestions on the other threads.

scott

 

Let me get this straight, you have a 90 model and it has an Opti dist? That is on an LT1 engine which didn't come out until 1992. The L98, which came in the 90 models, had a separate temp sending unit in the left cylinder head between the front 2 cylinders.

 

I have a 93 but I was reading the thread about the 90 engine and that the temp sensor was sending information about the engine being cold and so it was telling the system to use more fuel. I was not sure if the LT! in mine did the same if a temp sensor was sending information that said it was cold and would enrichen the fuel to engine.

 

In my original message I was looking at the gauges on the dash about the temperatures. Yeasterday on the way home I clicked on the digital readout of gauges, they don't match! The digital gauges must be more accurate as they read 180-181 for temp and 185 oil. Is there a way to adjust them?

 

None that I know of. The LT1 has a coolant temp sensor for the ECM that is separate from the coolant temp sending unit and they have a thermistor in them that creates fixed values based on temperature. If they seem off, replace them, if that doesn't fix you problem, then you have gauge control problems.