Cold start issue
Thread Starter
Instructor
Joined: Apr 2007
Posts: 160
Likes: 0
From: N Canton Ohio
Cold start issue
Ok Guys, I have a 91 coupe that just started to start hard when it's been sitting a couple days. It'll turn over for a while and finally start. When it's been running and restarted it kicks right now. If it sits for a couple hours, it's fine. I suspect a check valve. Is there a check valve on a 91 and if so, where is it? 
Le Mans Master
Joined: Oct 2008
Posts: 9,758
Likes: 49
From: Houston Texas
could be lost of things.. fuel injectors leaking, pump leaking back at the ck valve, fuel pressure reg leaking, dirty TB.
Check the fuel pressure while pinching the return line near the pump.
That will tell you if the pump is holding pressure. Ck the vacuum line going to the FPR for fuel and ck yout TB to see if its dirty.
Check the fuel pressure while pinching the return line near the pump.
That will tell you if the pump is holding pressure. Ck the vacuum line going to the FPR for fuel and ck yout TB to see if its dirty.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
And then there's the Coolant Temp Sensor which works like a choke - the colder the temp, the more fuel through the injectors. Scan it to see what it's sending after it's sat overnight. Should be right around ambient OR buy another one (12 Bucks) and plug it into the harness. If it starts, R & R the old one.
