Hey guys. I wanted to see if I could get some input on this. I have a 91 Si with a D16, it is rebuilt with about 60k since the rebuild. Since early this summer it has randomly been giving me problems starting. I would say about 9/10 starts are perfectly normal, but sometimes it just sits and cranks. It can take 10 - 20 times trying to crank for 5 - 10 seconds before it eventually starts. Sometimes it starts, sputters, then shuts off. It eventually always starts, but it seems to be getting worse and more frequent.

I have replaced the plugs, wires, fuel filter, distributor cap and rotor, and cleaned the fuel system and IAC. I also noticed that when cruising at low rpm there is sometimes some stuttering, it's very subtle, but seems to be related to the starting issue. The other issue which I also believe is related is that when I let off the gas and come to a stop, the RPM sometimes drop and it has even shut off a couple of times.

I am thinking there may be a vacuum leak, but wanted to get some more input.

Thanks!

 

1st check the main fuel relay. 2nd make sure the throttle cable isn't too tight

 

I agreed w/ relay... same problem then got new relay... notice when it rains problem came back bad leak driver side dripping all over all sorts of wires...

 

does it do it more on hot days?

main relay, it's under dash on drivers side footwell,

 

i'd go for the Main Relay, take that out and check out to see if there are cracked solder joints on there. re-touch em up with a soldering iron if you've got one.
Also check the batter connections, make sure they are clean and on very tight. i've seen that cause funny issues too

could be a vacuum issue too, check all of the little hoses on the intake.

 

http://techauto.awardspace.com/mainrelay.html