hornbm

I ran out and got a vacuum guage tonight. And at 2500 RPM, i'm getting only 6 inches of pressure. I should have at least 14 more inches.

Nothing is leaking, I've checked everywhere. And if it were something it would have to be HUGE to loose that much vacuum.

I allready tried blocking off the ACV, that didnt do anything. I thought it did earlier but now the vacuum guage shows thats not true.

Checked the brake booster, all of my vacuum lines are new. I replaced them one at a time to make sure I didnt mess any of them up.

I have new grommets on my fuel injectors as well, so that cant be it. The only thing left wide open is the air injection to my cat (manifold side). I dont have that hooked up right now. What the hell could be casing this?

ERAUMAZDA

gaskets??

hornbm

ALL new gaskets, this is a rebuilt engine.

hornbm

bump

DaleClark

iTrader: (55)

Does the car idle? Vacuum readings at higher RPM are much different than at idle - can you get the car to idle?

Time to get out the starting fluid and find the leak.

Dale

hornbm

no the car will not idle at all. I did get it todle once by really advancing the timing and pretty much opening the air adjust screw all the way. It was running at 1000rpm, and running like ****.

Now I know vacuum only increases as the engine speed goes up, so its probably way lower.

Again does the air injection for the cat on the manifold side being left open have anything to do with it?

Fingers

Not unless it's the ACV you left open. If it's just the split air port, then ignore it, doesnt matter.

However, you do have a vacuum leak still... i have no clue where... did you block off all the emissions? are all clamps after the AFM tightened?

Bambam7

Is it a brand new rebuilt engine??
Sometimes they won't idle. Is it very hard to start without flooding??
The apex seals probably have to seat... Try pegging it at 2-3000 for 15 minutes or more. it may help.. just keep varying it a bit.
You would hear a vacuum leak too- listen carefully! You'll find it.
There are two hoses that attach after the AFM... make sure those are on there- it's common to forget those or have them come off.

Acb1450

if you had a vacuum leak you should be able to hear..just listen. Go out and get a mechanics stethiscope

hornbm

yeah the engine has got only 80 miles on it. I got those 80 miles by tightening down the throttle cable soi it wont die when I let up off the gas.

Yeah this is absolutely driving me crazy, I wernt out withe carb cleaner and sprayed everywhere there could be a leak, and I didnt find anything, I tried listening too.

I even hooked up the air injection to the cat to see if it would make any difference. Didnt make any other than the exhaust sounds more even.

there is one clamp missing, its the one that holds the AFM onto the air inlet. I went and I couldnt hear a leak, nor feal it. And even if it was leaking from there, I hooked the vacuum guage up at the dynamic chamber, so it wouldnt effect vacuum there either.

Now could this be simply becaus ethe engine is not broken in yet? It was done with used rotor housings, but all the how to's out there say to set the idle to 1500, because it will have problems idleing below that. I cant get it to idle period.

Now heres something, the engine seems to keep sucking up coolant. I'm contantly having to refill the overflow tank. Yet theres no white smoke comming out of my exhaust. Where could it be going? My cooling system is more than sufficient, new radiator, black magic fan, new hoses. I dont see where thats going.

One last thing when I had to grind down on the end sideplate (I have an S4 block) so I could fit my S5 UIM to it, I went a little too far, and theres a little hole in the dust cover. I dont think it would make a difference, but I figured I'd throw this in.

Mabey theres a problem with the engine itself? It shouldnt be sucking up coolant like it has been.

hornbm

bump

MaxRX7

https://www.rx7club.com/forum/showth...e&pagenumber=2

I'm curious to find a solution, because I can't my engine to idle properly

RETed

Uh, how do you know you're losing vacuum at that high of an RPM range???&nbsp Most vacuum numbers are for idle speeds UNDER 1,000RPM.&nbsp You actually LOSE vacuum as engine speeds increase because the more open throttle plates decrease the pressure differential, and this kills "engine vacuum".


-Ted