engine miss when cold

[07blowngt]

Has anyone ever had this? When starting the car it seems like its running on about 6 cylinders, very flat, pops thru to exhaust a little. It will run like that for awhile until warm (195). After hot it runs great. The engine is a blower motor. Wondering if there is a sensor or something that is failing. The tuner I use is 3 hrs away and was hoping this is something that may be corrected at home

Thanks for any suggestions, Rob

 

[05moneypit]

This a new problem or something tha has been there since the build?

 

[Captainstr8edge]

did you check for codes?

 

[07blowngt]

miss

No codes and its somewhat new. Don't drive it much. Thinking could It be injector clogged but why would it clean up after warm?

 

[fordracer666]

Curious to see what you find out . Mine does the same thing I think it
May be tune related .

 

[07blowngt]

tune

Wonder if reloading my tune would do anything? not sure if a tune could change somehow

 

[BruceH]

How long have the plugs been in? Forced induction is hard on plugs.

 

[07blowngt]

plugs

Plugs are new (Brisk 3vr12s) blower plugs

 

[555]

I had no luck with Brisk plugs I went to NGK Irridium and never looked back

 

[07blowngt]

ngk plugs

I run NGK V power racing plugs in my 418 race car and love them. What heat range are you running in yours. I am 540 hp. about 16 lbs boost. Would you rec. a p/n to start with

 

[555]

I have newer style heads and run 1 step colder NGK 7554

 

[petersonb]

Same problem here. Like there's a "dead zone" when accelerating, if accelerating too much. Even in summer time!

I assume mine is tune related. Mine's a stock 4.6 3v with the Eaton M112 2.3L supercharger, Dept of Boost manifold and GT500 parts, etc....

Would be awesome if someone knew it to be something else, and it was an easy fix!

 

[BruceH]

Same problem here. Like there's a "dead zone" when accelerating, if accelerating too much. Even in summer time!

I assume mine is tune related. Mine's a stock 4.6 3v with the Eaton M112 2.3L supercharger, Dept of Boost manifold and GT500 parts, etc....

Would be awesome if someone knew it to be something else, and it was an easy fix!

You could always try another tuner. I had a Whipple that behaved like you describe and it was tune related.

 

[07blowngt]

plugs

Replaced the Brisk plugs with HT0 Autolites and the car ran great. The brisks were 2 degrees colder and the HTO are 1 degree. Old brisk(200 miles) were black like its alittle fat and not sure if HTO will help that but thinking of replacing o2 sensors as well

 

[s8v4o]

It's not losing coolant is it?

 

[07blowngt]

coolant

No. Coolant level has been good

 

[BruceH]

Replaced the Brisk plugs with HT0 Autolites and the car ran great. The brisks were 2 degrees colder and the HTO are 1 degree. Old brisk(200 miles) were black like its alittle fat and not sure if HTO will help that but thinking of replacing o2 sensors as well

It looks like you are one more member who has had issues with brisk plugs.

Do you think the o2 sensors are both bad and causing the ecu to add more fuel than is necessary in closed loop? You could pull your ht0 plugs and see how they look.

 

[05moneypit]

I had no success with the Brisk plugs on the street. They would work fine at the track but always seemed to load up street driving. I have yet to have a HT0 cause a problem even at 25psi of boost....just needed to tighten the gap.

 

[07blowngt]

plugs

This has been the most helpful thread I have had. Simply plugs and I thought I HAD THE BEST. I am going to run hard tomorrow and check the plugs. The car ran great on HTO. I am thinking of changing o2 just cause there cheap. Thanks to all

 

[AutoXRacer]

With my original engine (4.6L two-piece plugs) I used to run 2 step colder Brisks.
They ran great in FL...since its always hot out there.

When I moved to WA State, my start ups were a little more challenged. As in it took more engine rotations to actually start as compared to in FL, it started up instantly.

In WA while the engine was cold I did notice a little stumbling...but disappeared once engine reach temperature.

But it never misfired.