[Bob88]

Just recently started having trouble starting when my car is cold.
Have to turn it over for 4-5 seconds, 3 or 4 times before it will start. Once it starts it runs fine, no problem, no codes. The car has always started up almost instantly when cold, so not sure what might have happened. Only thing I have done recently is replace the alternator, and the problem started showing up immediately after that. Is it possible I did something while changing the alternator?? Car is an 88 L98. Any help would be appreciated. Thanks.

Bob

 

[grumpyvette]

check to make sure the connection to the engine coolent temp. and mat and MAF sensors are firmly clipped on, that to a large extent controls when the engine ECU knows when to richen up the mix when first starting the engine when its cold. also check the cold start injector is correctly hooked up (its located on the drivers side rear side of the tpi (D and H in the picture) CHECK TO MAKE SURE THE VOLTAGE FROM THE ALTINATOR IS AT LEAST 13-13.5 VOLTS AT IDLE , voltage readings less than 12 volts will cause problems and in most cases indicate electrical problems

http://www.chevythunder.com/fuel injection mech. pg AA.htm

READ THIS

http://www.chevythunder.com/fuel injection troubleshooting pg D.htm

BTW carefully check the MAF sensor, if you broke that hair thin wire due to rough handling that can and will also cause the problem, and while your at it, heres how to remove the injectors if you choose too, BUT ITS VERY UNLIKELY youll need to clean them!
http://www.thirdgen.org/newdesign/tech/injectorswap.shtml

MOST PROBLEMS ARE ELECTRICAL /SENSOR OR CONNECTORS THAT HAVE BAD CONNECTIONs NOT FUEL RELATED,BUT CHECK THE PRESSURE ON THE SHRADER VALVE ON THE PASS SIDE FUEL RAIL, IT SHOULD BE AT LEAST 37-40PSI minimum

 

[Bob88]

Already checked all the connections, fuel pressure, etc. Did'nt remove the maf, so that should'nt be a problem, but I'll look at it anyway just to be sure. Anything else?? How about fuel pump relay, is there a way to check it?? Thanks.

Bob

 

[grumpyvette]

you should be able to hear the fuel pump kick on as the key is turned and watch the fuel pressure kick up to 37 psi, the oil pressure sending switch might be a problem if your having extremely low oil pressure at start up as it cuts off the ignition at pressures under 4 psi.
here read this
http://www.c4vettes.com/l98.htm

http://www.c4vettes.com/ecm.htm

http://www.c4vettes.com/sensorinformation.htm