I put a new fuel pump in about 3 weeks ago, had it tuned. And everything was all good for awhile. Until now, its getting pretty cold here, and now my car is having trouble starting. Its turning over fast enough, sounds like it wants to fire, but it just wont for awhile.

Then, when it does fire up, it dies right away if I dont give it some throttle. It also seems like its studdering to get up to 2k but as soon as it hits that, it starts idling like normal.

I'll try and get a video tomorrow to help explain what i'm saying.

Mods are:
Kelford 272's
TBE
MBC
Walbro
Stock injectors

Thats about all I can think of that could be a possible cause to my problem.

I just changed spark plugs last week sometime, so those should be ok still, unless its fouled them.

I hadnt had any issues in years past with start up at all, all was on the stock fuel pump though.

But has anyone else had issues like this?

 

What was new for the tune? Just the pump?

Had you already been running fine with all the other stuff?

The pump shouldn't really change much unless there's something wrong with it, or with the installation.

What are your fuel trims doing?

 

Did you gap your plugs? Where they different from what you had in there?

Also, I didn't see it but figure I'd ask, your not running E85 are you?

 

did you check for any vacuum leaks, vacuum hose could be damaged?

 

Yeah my car was running fine before the fuel pump, thats the only thing I added. Its just the first start up of the day that it wants to do it.

I didnt gap my plugs as they're iridium. But, they're the same plugs I had before, just new.

I'm on 91 octane too.

It only started doing it when it got down to the Teen's for temps here.

As for what my fuel trims were doing, I havent logged it yet, i'll try to get one tomorrow.

 

At first, thats what I thought it was too, But, the car runs fine and starts like a champ after its been run for awhile or whatever, its just that initial start up that it hates.

I was just going to deal with it, but I ran into a local with the same problem, only his fouls plugs like my 2 stroke dirtbikes used to do mines not that bad yet

 

I dont know how sensitive mitsus are but I know GMs have very similar issues when the ect sensors go out. Do you have any way to get a scan tool and read the values on the sensor or have specs on its resistance values at certain temps?

 

I dont have a scan tool, all I have is EvoScan, which might be able to do that. I'll have to dig through my repair manual if I can find my usb drive, they've gotta have something in there.

 

One other thing I can think of is that your throttle body plate could be sticking. It has that coolant circuit in them to keep them from sticking in cold weather but I would check the play on it make sure it opens and closes smoothly. You may have an issue with the idle air control valve as well. You can remove it and inspect it, then clean it off see if it helps. WIth a scan tool you can read the actual values of the valve and see if its within its range as well. I cant think of spark plugs causing this issue, especially only at cold start up. It certainly wont cause your vehicle to die. For future reference, all spark plugs should be gapped/checked to verify they are at where your vehicle needs them to be. Make sure you use the correct tool for platinum and iridium plugs and youll be golden.

 

i have the same problem, only i run E85 all the time, which i found out is a common problem...

 

Well, no video or data log today, it didnt do it, it was to warm out (about 45 degrees)