Spark Plug Gap Question

Casey2552 · Sep 16, 2013

Hi first post , I have a 1990 notch with ford racing motor with gt40 y303 heads , e303 cam , gt40 intake , 70 mm tb,prom mass air meter , 24lb injectors , egr was removed by previous owner , I installed a simulator on egr plug that did take care of alot of codes and turned engine light off my question is what should spark plug gap be , it idles pretty firm no surging but motor seem to jump all over with alot of shaking that runs through hole body , could this just be how the e303 cam idles all thaughts appreciated

Grabbin' Asphalt · Sep 16, 2013

I have gt40p heads, i got mine at .035, but they're super milled heads, believe a safe area to tune would be .045 then go up or down and see how she takes it.

Casey2552 · Sep 16, 2013

Thanks I tried .45 then tried .54 like ford racing tech said and now when I rev it it will go up come down and hang about 1100 rpm for a second then slowly come down to idle at 850rpm

Casey2552 · Sep 16, 2013

So can anyone tell me if the hangin idle after rev is normal , seems like my old one done it but can't remember , when it was at .45 it came straight down to 850 fast with no hang thanks

Rick 91GT · Sep 16, 2013

Typically a hanging idle is not from a spark plug gap I would check the IAC valve.... And tps voltage

Sent from my XT907 using Tapatalk 2

mikestang63 · Sep 16, 2013

disconnect the IAC and see if the problem goes away.

Casey2552 · Sep 16, 2013

I have set tps at .98 v I was told that would be best but iv read so much about tps most people say as long as it's below 1v it's good but I'm not sure on that issue

mikestang63 · Sep 16, 2013

don't worry about the whole TPS has to be at 1.0 myth. As long as it's within the range of .90 to 1 you are fine. I would think it's a sticky or bad IAC.

Casey2552 · Sep 16, 2013

Thanks I suspected that the hole time but I guess I told myself it should work I cleaned it lol , I'm just Gona replace it and go from there , in the process right now of undercoating with 3m rubberized undercoating any one have any good or bad things to say about undercoating

mikestang63 · Sep 16, 2013

it's a bitch to remove and will promote rust if you don't apply it properly with full coverage.

Casey2552 · Sep 16, 2013

Well just did half the car and cleaned up bottom best I could , it was in great shape as it was not much rust at all , geuss I will just hope for the best lol to late now but sure looks cleaner now , like new

Grabbin' Asphalt · Sep 17, 2013

My IAC sticks alittle too, I need to just buy a shiny one from Mike. Another way to to test in a manual car, is to put it in 1st gear and gain slow speed to 2500rpm and put in in nuetral and coast. Your sticky IAC should raise its ugly head and hover around 1200-1300-ish. My parking deck reminds me daily of my sticky one. Already got my gasket just lazy right now

Mustang5L5 · Sep 17, 2013

Spark plug gap is mostly dependant on ignition if you do not have a power adder or nitrous. On a stock N/A engine, there is no reason to reduce gap. The stock gap is 0.054".

hanging idle could be dirth 10-pin connectors on back of intake.

Spark Plug Gap Question

Casey2552

Member

Attachments

Grabbin' Asphalt

Casey2552

Member

Casey2552

Member

Rick 91GT

Mustang Master

mikestang63

Casey2552

Member

mikestang63

Casey2552

Member

mikestang63

Casey2552

Member

Grabbin' Asphalt

Mustang5L5

That is…until I whipped out my Bissell

Similar threads

Spark Plug Gap Question

Member

Attachments

Member

Member

Mustang Master

Member

Member

Member

That is…until I whipped out my Bissell

Similar threads

Privacy & Transparency

Privacy & Transparency