Cold Start Problem

[taylor89]

I have a problem that doesn't seem to want to go away. Every time I start my car cold it takes an average of 60-90 seconds of cranking intermittently to get it started, which can't be good for my starter. Every 20 seconds or so it sounds as if it is starting up, so I try to give it a little gas and it immediately dies.

The odd thing is that is runs at 100% after I get it started. I do not have any liquid leaks of any kind that I know of. I've replaced the distributor, cap & rotor, fuel filter, air filter, ignition coil, spark plugs, spark plug harness, ICV, and the cold start valve. The only other thing I can think of to replace is the fuel pump/relay, which I will be doing later this week.

Does anyone else have any ideas?

[PiercedE30]

maybe the one way valve at the fuel pump is letting fuel flow from the rail back into the tank.

[taylor89]

That's definitely something I will check. Where is it located? Right out of the fuel pump?

[Mike325]

It is probably the cold start valve. It is located on the intake above the valve cover. When the engine is cold, take it off by removing the two allen bolts. Then, put it in a cup and have someone crank your engine. Fuel should be coming out. Do this and get back to us. My eta did the same thing. I will tell you what to do if no fuel is coming out. I have to go to work now lol.

[taylor89]

I replaced the cold start valve first thing after it started, but no dice. I'll check it anyway and get back to you.

[taylor89]

You were right--there is no gas coming from the cold start valve, though with the valve off it won't stay running at all after it starts unless I gas it.

[auto da fe]

Bad temp sensor?

[backtrail69]

That is because there is a hug vac leak...

[Mike325]

Ok, good work. Now, to fix this problem. There is a switch called the thermo-time switch. This is a sensor on the top, front of the engine, infront of the injectors iirc. It is a two prong switch. It senses coolant temps and when it's cold, it will tell the dme to give the cold start valve fuel. Your's does not work.

[mcgrath]

The cold start valve won't do anything if there is no fuel pressure on it. most likely the one way valve (check valve) in the fuel pump has gone bad. I actually have the same exact problem except I run the later "i" motronic so I have no CSV, but I have a new walbro 255 HP pump so I'm thinking my FPR might be going out. I am going to borrow one tomorrow after work. I will let you know if that changes anything. my bet is on the fuel pump in your case though.

[mcgrath]

mike325 is correct also I just didn't his post (slow typer) :)

[PiercedE30]

the check valve isn't actually part of the pump, it is on the feed line on top of the tank under one of the access holes.

[taylor89]

Awesome. I'll pick one up and let you know how it turns out. Thanks for the help.

[mcgrath]

the check valve isn't actually part of the pump, it is on the feed line on top of the tank under one of the access holes.

He has an 86 not a 90. there is only one access hole and it has a completely different fuel system. The check valve is in the external pump.

[PiercedE30]

shit, my bad.....i don't know what i was doing then.......