drexel_j

I have 230,000 miles on my 95 Impala SS and 190,000 on my 95 Corvette both are LT1's and neither have had any problems.

I used a Painless wiring kit with a 93 computer on my LT1 and what I found out was that when you try to start the engine the computer will turn on the fuel pump and if it doesn't start after 3 seconds it will turn it off. When the engine starts the computer will turn it back on. Your fuel pressure regulator should hold the pressure until it starts if it takes longer than 3 seconds. Connect a fuel pressure gauge to make sure you are getting correct fuel pressure.

There is one wire that you need in your wiring harness that connects to your compressor lead (when the compressor is on it sends a signal to the computer) and then if your computer is propgrammed to recieve the siginal it will increase the idle.

The Optispark is new; I tried connecting an extra injector and I could never feel the solenoid click, I tried the 12 volt light, it was very sporadic and dim.

I have an LT1 with Painless wiring harness and a 1992 computer. It just stopped running the other day; the spark is good but I don't feel like the injectors are opening properly (I do have 43 PSI at startup). How do I test the Injectors from the computer, I think I might have a bad computer (I just put in a rebuilt computer about a month ago).

I have a 1995 LT1 with a Painless wiring harness for a 92-93 Corvette I am having problems with the idling; when I start it up it will go to about 1200 RPM and then go to around 900 to a 1000 which is fine as I have a Crane 227 cam as my only modification. The problem is when I am driving and I let off the gas suddenly (it is a 5 speed) it will go to around 200 to 500 RPM and die, it starts and runs fine. I had FIS burn the chip and this is the last problem I have in getting the car going properly. Does anyone know it it is the computer or the chip that determines what the idle should be. I think they set the idle in the chip to low when they programmed it. I have reset the IAC and have tried it from another LT1 that worked properly and it did the same thing. Any sugestions?

I am only checking it going into closed loop mode at idle; i am also having a problem with the idle dropping down to 500 600 RPM after a few minutes and then the car will die, it needs to maintain a 900 RPM idle.

I don't have any codes; I do have a 160 thermostat but the engine does get up to 195 when the fan turns on, any more ideas?

How would I see if the ECU is reading the O2 sensors; I have no trouble codes, it jsut won't go into closed loop mode and I understand that the system won't go into closed loop untill it reads the O2 sensors.

I have a 92 LT1 with long tube headers and it won't go into closed loop mode and I think it's because the O2 sensors are at the end of the headers. If I install a 4 wire O2 sensor instead of the one wire does anyone know how I should wire them and what to use?

I was talking to a guy at FIS in SA and he had me look at the color code on the wires going the IAC and it turns out they were wrong, Painless wiring said they had a problem with some of the harness they made a few years back and told me how to correct it. I will report back when i fix the harness and see how it runs.

I have a 1992 LT1 Crate engine that I put a Painless wiring harness on and I can't get it to idle. The only modification from stock is a Crane 227 cam. It starts fine but idles at 1500 to 1600 RPM; I have blocked off all of the vaccume ports and sprayed the intake with both water and WD-40 and it doesn't make any difference. I am running 22 LB injectors, all new sensors and had my chip burned by FIS out of SA, they told me the chip makes no difference untill the system goes into closed loop. I have long tube headers with the oxygen sensors in the collectors. Any ideas.

I've been using them for several years and can't tell a difference over the rubber ones except that the engine doesn't move around as much

If this is a new LT1 and not a LT-1 from the seventy's how do you get a performer rpm intake to work on it?

You can vent your 94 Opti so that you won't have that problem any more. To Upgrade to a 95 you have to change the timing cover, the pin in the camshaft and the Optispark. You can go to this site and it will tell you how ot modify yours. http://www.corvettefever.com/howto/16758/

When my 95 Impala burned the coil wire in half at 50K the shop said it was the Optispark, I put on a new set of MSD wires and still it wouldn't run. I changed the Coil Driver module (it is the little module that is mounted right above the coil) and it's worked great ever since. I have a 1994 Camaro LT1 that seemed like the fuel pump went out and we changed that and it ran for a while, but a little latter it stopped running again. Took it to a shop where they said it was a bad Optispark and computer. When we changed the Optispark and it would start but ran worse than before, as in starting but immediately dying. We changed the oxygen sensors, plugs, and still nothing. I changed the coil driver module and it has run great ever since. I think they are quite sensitive and if something happens in the electrical the just give out. No shop I have ever been to has ever recommended changing this out. I think I will keep a spare one.