Ok this is kind of stupid question, but if apex seal is bad, can it shake and sound like blown engine only when you start it once, and then whole week it drives like it's perfect?

This happend to me yesterday. I started it and it started shaking, like crazy, vaccum only like 10 or so. So I shut it down, touched stupid MAP sensor and turned it back up and it runs great again.

I'm suspecting Map sensor, but is it possible for it to sometimes work but when it stays over night and then in the cold morning it goes to ****?

Give me your opinions, i'm trying to get a map sensor just in case.

Amel

 

Maybe there is a leak in the map sensor hose, or the check valve has gone bad.

Still probably the sensor, but have a real good look at all the other stuff before you swap it.

 

there is no check valve in the map sensor hose. it is a filter. the hose may be leaking also look at the connector. when you replace it reset the ecu also

 

I get this sometimes as well, but I'm thinking its most likely since I got rid of my emissions and air pump. Therefore there is a glitch that occurs making my idle rough and vacuum below 15. I'm just going to tell you what everyone has always told me, get a PFC

 

Amel,

I think it might be the MAP sensor.. Never really heard of one working partially, but I'm sure it's possible. Maybe the connections inside are bad. Come get mine.

 

I already did

 

So, did it work? Hope so.. I feel bad for even taking your money ya big goof! Thanks for the help too..

 

I didn't put it in yet. I'll put it in tonight probably, and i'll let you know. Should be fine now i think

 

Now if it is your MAP sensor then great, no major problem and a easy fix.

But I have had a something close to that happen in two of my rides and my buddies ride does it more often.

On cold or simi cold starts the car will idle bad and shake. I have noticed vacuum was low on my 3g but can't say for sure on the others (not enough gauges to tell). Sometimes shutting the car down helps and others it just needs to fully warm up and very engine speed for a bit. After a few minutes it all goes away and the idle is normal and rock solid.

I was trippin on this for years. Just a few months ago I thought it could have been a carbon stuck apex seal that frees it's self once warm? This would cause two chambers to lose compression and act like a blown motor. Other then that I have no idea. Both engines have been compression tested and are it great shape. Compression is not an issue although I have never compression checked the engine while this was happening. It happens very few and far inbetween.

Just sounds like what I have run into and wanted to share my experience.

 

Yes, update us with the information as to if it was the map sensor. Also did you do any mods recently, did it just start acting up out of nowhere?