Hard start and rough idle

Dtchy · 08-04-2008, 01:08 AM

My car is acting up, even though I pamper it so much...

Starting the car has gotten progressively worse in the last few months. I have to crank it about 7 or 8 times until it finally comes to life...very rough.

It all started months ago when the idle would keep hunting up and down, and now it's getting to the point where she doesn't want to start up properly. After about 30 seconds the roughness goes away and the car idles normal. Also during driving or idling at a traffic light no problems.

I especially notice it when the car is warm (like after filling up or getting lunch).

What could this be? I'm thinking ICV. I did a search but could not find any decent results on a similar problem.
I'm planning on redoing the fuel system and sending out my injectors to WH. Hopefully that cures it.

I have to note that I did replace the FPR, but that didn't help.

Any ideas?

paper1122 · 08-04-2008, 04:04 AM

I had a similar problem with my Acura. It was actually my fuel pump relay in the case of the 944, the DME relay. If the car sat out in the sun all day it sometimes wouldn't start at all. You might try making a jumper per Clark just for kicks and giggles.

Dtchy · 07:10 PM

Quote:

Originally Posted by paper1122

I had a similar problem with my Acura. It was actually my fuel pump relay in the case of the 944, the DME relay. If the car sat out in the sun all day it sometimes wouldn't start at all. You might try making a jumper per Clark just for kicks and giggles.

I made a 3 wire connector like in Clark's and jumpered 87, 87b and 30.

The car fired right up. The idle hunting was still slightly there, but at least the car started. Does this mean that the relay is the culprit?

The fuel pump doesn't turn on when the engine is not running correct? So am I losing fuel pressure in the rail somehow?

paper1122 · 08-05-2008, 12:14 PM

Yeah, it sounds like you have a bad Relay, I just picked up two from PP. The pump should be off when you are not running the car so if you are going to keep the jumper in you'll need to install a switch on the 30 lead. What is most likely happening if you have a bad relay is when you first go to start the car your using up the fuel that in the rail right away and you have to wait till the pump finally kicks on before it re-pressurizes.

You might try some fuel injector cleaner for the "hunting".

Dtchy · 08-05-2008, 07:11 PM

Well, I bought a new relay today and it seems to be just a tad better, but the problem still persists.
The car starts slightly better but the hunting is still there for about 10 seconds...really strange.

I have a new fuel check valve and fuel dampener laying around that I still wanted to install. See if that cures the problem...

Dtchy · 08-18-2008, 04:45 PM

OK, this problem is definitely temperature related!

Last Sunday I didn't start the car until in the afternoon when the sun was just brutally hot. This means the car was hot as well, even though it hadn't run all day.
I got the same symptoms...very hard starting very rough idle.

This was the first time I actually let it sit, since I normally start it on my way to work in the morning when it's still cool out without any issues.

Anybody got any ideas what can be a temperature related issue? Maybe engine temp sensor?