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420A Brian crower cams p0300

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Have you read through the causes and symptoms list of this code? That'd be the first place to start.

This is the reason why everyone who plans to actually buid their 420a needs Megasquirt.

Here is some info. Courtesy of dsmtalk.com
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Hey would you know of any site i can go to in order to buy a megasquirt ecu? Ive been looking everywhere and everyone of the sights are out of stock. Ive looked into dyiautotune but never assembled a megasquirt ecu.
 
Hey would you know of any site i can go to in order to buy a megasquirt ecu? Ive been looking everywhere and everyone of the sights are out of stock. Ive looked into dyiautotune but never assembled a megasquirt ecu.
I'm having the same problem. I cannot find any. Not even used. I sent an inquiry on the MS website and hopefully they'll get some more in stock. I just don't think there is a large enough market for them.

Don't expect me to tell you when I find one. Because I'll be buying it for myself.
 
I'm having the same problem. I cannot find any. Not even used. I sent an inquiry on the MS website and hopefully they'll get some more in stock. I just don't think there is a large enough market for them.

Don't expect me to tell you when I find one. Because I'll be buying it for myself.
Lol alright sounds good i might just go the dyi route
 
@ShonDope Try buying the new IAC if yours is stock. Buy a quality one, not a cheap trashy one.

I just had a new idea. Is your crankshaft sprocket stock, or has it been replaced?
I believe the sprocket is stock. I know the harmonic balancer is new because I bought it a few months ago. The iac I have is also only a year old but it’s only held on with one bolt and some gasket maker because one of the bolts broke off and I couldn’t manage to get it back out
 
it’s only held on with one bolt and some gasket maker
Well that's no good. I bet it's leaking vacuum. And I also bet it's not getting a proper reading. Do you have a welder, or anyone close that has a welder? You can weld a nut on that broken bolt and then back it out. And get a new one from the hardware store. Or the only other option is to get a whole new throttle body, but the other route is most likely cheaper.
 
Well that's no good. I bet it's leaking vacuum. And I also bet it's not getting a proper reading. Do you have a welder, or anyone close that has a welder? You can weld a nut on that broken bolt and then back it out. And get a new one from the hardware store. Or the only other option is to get a whole new throttle body, but the other route is most likely cheaper.
I’m just gonna get a throttle body tomorrow from the junkyard. I’ve been meaning to do it and I’m gonna be taking my old throttle body out tonight anyway
 
I’m just gonna get a throttle body tomorrow from the junkyard. I’ve been meaning to do it and I’m gonna be taking my old throttle body out tonight anyway
You might as well pick up a new TB gasket as well. Mine cost like $4 for a Fel-Pro. At you local store it should be in stock
 
Hey would you know of any site i can go to in order to buy a megasquirt ecu? Ive been looking everywhere and everyone of the sights are out of stock. Ive looked into dyiautotune but never assembled a megasquirt ecu.
DIYAutoTune should be able to assemble one for you, then all you have to is wire it in. I emailed "[email protected]" to inquire about one, and they were very helpful. I would give that a try if you were serious about getting one.
 
I believe the sprocket is stock. I know the harmonic balancer is new because I bought it a few months ago. The iac I have is also only a year old but it’s only held on with one bolt and some gasket maker because one of the bolts broke off and I couldn’t manage to get it back out
The reason I asked about that sprocket is because the engine has to be at TDC to replace it, otherwise you timing will always be off.

Give us an update once you install the new TB and IAC valve.
 
The reason I asked about that sprocket is because the engine has to be at TDC to replace it, otherwise you timing will always be off.

Give us an update once you install the new TB and IAC valve.
Replaced the throttle body and the idle sensor and still have the same problem. At this point the only sensor in my car that isn’t brand new is my throttle position sensor. And I looked online and saw that a failing TPS can cause stalling at idle and misfires. So I’m gonna order a new TPS when I get paid and see if that changes anything
 
Replaced the throttle body and the idle sensor and still have the same problem. At this point the only sensor in my car that isn’t brand new is my throttle position sensor. And I looked online and saw that a failing TPS can cause stalling at idle and misfires. So I’m gonna order a new TPS when I get paid and see if that changes anything
It should throw a code for the TPS if it is bad. You can go ahead and try it just to be sure but my car threw a code for the TPS.
 
It should throw a code for the TPS if it is bad. You can go ahead and try it just to be sure but my car threw a code for the TPS.
I’ve been reading online about symptoms for bad TPS sensors and sometimes they kick codes for misfires instead of the TPS. And my idle is usually ok but it bounces about 200 rpm up and down and I get small idle surges here and there. When my car starts to act like it wants to stall it will drop to about 500 rpm then rev up to about 1200 for a second before coming back to 800. I know I have fuel and I know I have spark so it’s gotta be some kind of air flow problem. But I know I don’t have any air leaks because I’ve checked every gasket and opening. So it’s gotta be electronic right? If a sensor is giving a bad reading it will confuse my system into thinking I have other problems
 
I’ve been reading online about symptoms for bad TPS sensors and sometimes they kick codes for misfires instead of the TPS. And my idle is usually ok but it bounces about 200 rpm up and down and I get small idle surges here and there. When my car starts to act like it wants to stall it will drop to about 500 rpm then rev up to about 1200 for a second before coming back to 800. I know I have fuel and I know I have spark so it’s gotta be some kind of air flow problem. But I know I don’t have any air leaks because I’ve checked every gasket and opening. So it’s gotta be electronic right? If a sensor is giving a bad reading it will confuse my system into thinking I have other problems
Well if you believe that's the case then try the TPS for sure. Then report back.

Although these symptoms do sound like a heavy vacuum leak. You said you checked for air leaks? Do you still have your vacuum stuff, or has it been deleted? How about your evap system? I doubt a vacuum leak would cause a misfire, but definitely an idle surge.
 
Well if you believe that's the case then try the TPS for sure. Then report back.

Although these symptoms do sound like a heavy vacuum leak. You said you checked for air leaks? Do you still have your vacuum stuff, or has it been deleted? How about your evap system? I doubt a vacuum leak would cause a misfire, but definitely an idle surge.
I haven’t done any deletes on my car so I still have the egr and the pcv valve on the car. But I’ve replaced both already and I’ve replaced the hoses from the plastic brittle hoses to a larger rubber hose. And I’ve done the wd40 leak test on all my stuff to see if there are any leaks and I didn’t see any change. I haven’t checked my evap system yet but I don’t see that being the problem
 
If you haven't done a compression and leakdown test yet, I would suggest doing those 2 things so we know your engine is healthy first. Also did you replace the cams with head on or off the block?
I left the head on the block when I did my cams
 
My compression test came back 175, 175, 175, 185. So I guess I can rule out my engine?
 
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