85 cold start issue
Thread Starter
8th Gear
Joined: Apr 2014
Posts: 8
Likes: 0
85 cold start issue
Alright I'm at a dead end with this one.. 
my car is a 85 coupe all stock except for the basic mods k&n ect.... The problem is that the first start of the day is terrible the car simply doesn't want to start at all finally after lots of cranking it will slowly come to life and run great. I have replaced the fuel pump, fuel filter, every sensor on the car is brand new (including the cold start switch), it has new Bosch 3 correct 24# injectors, all vac lines are new, new fuel pump relay, new fpr diaphragm, new plugs wires coil rotor and cap. After the first start of the day the car will start pretty good the rest of the day but the longer I let it sit the longer it seems to crank. This repeats every day a any suggestions?
my car is a 85 coupe all stock except for the basic mods k&n ect.... The problem is that the first start of the day is terrible the car simply doesn't want to start at all finally after lots of cranking it will slowly come to life and run great. I have replaced the fuel pump, fuel filter, every sensor on the car is brand new (including the cold start switch), it has new Bosch 3 correct 24# injectors, all vac lines are new, new fuel pump relay, new fpr diaphragm, new plugs wires coil rotor and cap. After the first start of the day the car will start pretty good the rest of the day but the longer I let it sit the longer it seems to crank. This repeats every day a any suggestions?
Drifting
Joined: Jun 2013
Posts: 1,590
Likes: 60
From: ft myers FL/Munising MI
hook up the pressure guage at the rail...make sure you have the required pressure...I had this issue...was the fuel line not in the pulsator correcctly....pumps the fuel back into the tank....make sure pressure comes up and stays up for a few minutes...monitor it when starting...
Racer
Joined: Jun 2001
Posts: 376
Likes: 10
From: Chicago IL
I had the same issues long ago and solved the problem. I agree it's fuel related. Two things to check. Chances are one or more injectors are leaking. Also, I'll bet your fuel pulsation dampner (in tank) is leaking also causing the pressure to bleed off quickly - replace that with a short piece of fuel hose.
Intermediate
Joined: May 2008
Posts: 36
Likes: 0
From: Katy TX
You may have a fuel pump relay issue. When you turn the ignition switch to RUN (Not START), the ECM should send 12V to the fuel pump relay coil for two to four seconds, causing the fuel pump to run for that time to prime the fuel system. You should be able to hear the pump running. Also, you should hear a click sound under the dash when the the relay times out (after the 2 to 4 seconds). If you have a fuel pressure gauge, check the fuel rail pressure. You should see about 45 PSI with the ignition switch in the RUN position, but with the engine not running.
Good luck!
Good luck!
