keremarsan
Well-known member
Hi ,
Since some times, my car has rich cold start situation.
For the first 3-4 sec , the car cold starts perfectly with approx 900 -1000 RPM. Then RPM decrease to 800 and I can feel the engine not comfortable and smell the gas from exhaust pipe.
This situtation continues for 20-30 sec then suddenly ca begins to run normally, as the temp is low, RPM increase to 1000-1100 and after warm up, decrease normally to 600-700.
The problem begins some month ago with a strange noise of "friction"( I can hear this even the car is hot and run normally ) .
It is a well maintained 1988 corvette with 84.000 miles on it ( I have it since 2006 , since 62.000 org miles ) . Noise is present, there is no problem of oil presuure, no error code .
It is strange that the cold start rich problem begins with this "friction"noise that I can not find where is the source ( looked at air pump, try to here with stetoscope, noise seems to come under the car , but can't find the source. )
I made the iddle setting following the procedure , TPS at iddle is 0,54 V, spark plugs are new Bosch platinum ( I was having same problem with previous spark plugs ) , If I describe the strage frictionsound, it seems to come because the engine is not comfortable due to a ignition problem. But I have plenty of power any loss of power is present.
I have a second ECM with Hypertec street runner chip ( I have a 180 degre thermostat ) , I canged my ECM and same friction sound , cold start issue is always here.
I can hear and feel the "friction sound " even in decompression of the engine.
Fuel pressure is normal ( start and running ) , fuel injectors were changed las summer with 24 LBS accels and work great until now.
This strange "friction noise" and cold start rich issues make me very sad. I have a lot of expreience in mechanic but can not find the solution .
( I have already ordered new water pump, new air pump , air pump delete kit, BBK 52mm throttle body etc and try to change everything to find a solution ).
IACV also is new. ( but the original was better I think )
I have also a new Cold Start Swicth and think to change it, ( just under the air intake coupler ) but I have already eliminated the cold start injector.
My car has now a 1989 model year hypertech performance chip to help te cold start by using main injectors.
But even with the standart 1988 chip, I have the same problem.
Any additional information wil be helpfull
Thank you for your help
kerem
Turkey
Since some times, my car has rich cold start situation.
For the first 3-4 sec , the car cold starts perfectly with approx 900 -1000 RPM. Then RPM decrease to 800 and I can feel the engine not comfortable and smell the gas from exhaust pipe.
This situtation continues for 20-30 sec then suddenly ca begins to run normally, as the temp is low, RPM increase to 1000-1100 and after warm up, decrease normally to 600-700.
The problem begins some month ago with a strange noise of "friction"( I can hear this even the car is hot and run normally ) .
It is a well maintained 1988 corvette with 84.000 miles on it ( I have it since 2006 , since 62.000 org miles ) . Noise is present, there is no problem of oil presuure, no error code .
It is strange that the cold start rich problem begins with this "friction"noise that I can not find where is the source ( looked at air pump, try to here with stetoscope, noise seems to come under the car , but can't find the source. )
I made the iddle setting following the procedure , TPS at iddle is 0,54 V, spark plugs are new Bosch platinum ( I was having same problem with previous spark plugs ) , If I describe the strage frictionsound, it seems to come because the engine is not comfortable due to a ignition problem. But I have plenty of power any loss of power is present.
I have a second ECM with Hypertec street runner chip ( I have a 180 degre thermostat ) , I canged my ECM and same friction sound , cold start issue is always here.
I can hear and feel the "friction sound " even in decompression of the engine.
Fuel pressure is normal ( start and running ) , fuel injectors were changed las summer with 24 LBS accels and work great until now.
This strange "friction noise" and cold start rich issues make me very sad. I have a lot of expreience in mechanic but can not find the solution .
( I have already ordered new water pump, new air pump , air pump delete kit, BBK 52mm throttle body etc and try to change everything to find a solution ).
IACV also is new. ( but the original was better I think )
I have also a new Cold Start Swicth and think to change it, ( just under the air intake coupler ) but I have already eliminated the cold start injector.
My car has now a 1989 model year hypertech performance chip to help te cold start by using main injectors.
But even with the standart 1988 chip, I have the same problem.
Any additional information wil be helpfull
Thank you for your help
kerem
Turkey