So i just put in my newly rebuilt motor,without the rats nest. I didn't plan on removing the rats nest but it waqs damaged when installing the negine so i decided i might as well remove it know. i used the rotary resurection instructions for my s4 NA. i didn't have the block off plates so i installed the egr valve with a nipple on the end and did not remove the BAC valve or coldstart syste, or ACV. now i was unable to get it to start after a little bit i double checked fuel and spark and it was getting both. I decided to try and pull start it and it worked! the engine started and ran but won't run under 2800 rpm so i pulled it into the garage to check for vacum leaks and i still havn't found any so does anyone have any advice as to why it won't run under 2800 rpm or documentation of every vacum line to check.

Thanks ahead of time
-Bobby

 

Try stabbing the CAS again, and see if a little oil to build compression will help things along. You've probably got a vacuum leak somewhere. Remember, not only vacuum leaks, but UNMETERED air as well can screw things up. That's anything between the MAF and TB.

 

you meaqn install the CAS again?

 

Yeah, you do know there's a special way to install it..... right?

 

well i did reinstall the CAS correctly by aligning yellow mark to pin and the pin on collar of CAS with the mark on the CAS housing but it still wont idle. i can only get it to start by bumb starting it or pulling it around the block. it starts relatively easily using those methods. however once it starts it still refuses to idle as soon as it gets under like 1800 rpms now it will die. its rebuilt with all knew seals s5 rotors and large streetport so i have the idle speed screw all the way up and the a/f all the way rich and it still won't idle. so anymore ideas?

 

i remember reading that rebuilt engines can also have low compression thus making them harder to start.

read this... this will help explain.

http://www.rotaryresurrection.com/2n...p_breakin.html

 

if its too rich it won't idle. perhaps try to get around at least 13:1. 14:1 would be better for just idling

 

If he's got vac leaks, means is running the AFM and that usually means not running a standalone and can't adjust fuel, and the stock maps are fine (Rtek is the exception).

Rebuilds will indeed have terrible compression if new hard seals are used and will be very hard to start for a while. You can do what I did and add maybe a tablespoon of motor oil to each leading sparkplug hole, then start it. Keep in mind if you do this, it's going to smoke like a bitch.

As for idle, there are a number of ways to locate vac leaks, a little beit of searching will bring you all of them. When I rebuilt mine, I did a poor job with the LIM and had to take it apart, put a dab of RTV on the gaskets, then all was better. My favorite way of locating bad vac leaks is to take a few foot length of vac tubing, stick one end in my ear and probe around the engine with the other end while its running and listen for hissing.

And finally, if you have the car running at all then the CAS is more than likely stabbed correctly, but you'll still want to set the timing properly with a timing light.

 

i think i will have to try the rtv on the LIM gasket i justy assumed since it was new that it wouldn't need it also i found this while inspecing for vac leaks. anyone know where it goes it looks like the connector broke off of it

 

^no picture coming up for me.

 

^Scrims is right. Finding vacuum leaks can be a bitch, but you can use a can of brake cleaner with it running to find it. It'll sound different when it hits the leak. Here's some crazy food for thought: My rebuild was HARD to start as well. It finally started after lots of cranking and de-flooding, schmoozing, etc. It took me a long damn time to figure it out, but I realized that I installed the CAS drive gear backwards. Don't know how I did that. I know (and knew then, too) how it's supposed to go on. I pulled the front cover and saw that pretty much right away. I flipped it, reinstalled the front cover, re-stabbed the CAS, and it fired up first try. It may not be your situation though, but worth a thought

 

my bad here is the pic,

Anyway the plan is to take of the UIM tomorow and double check all the vacum nipples then go ape **** with RTV. is there anyway to see if you have proper vacum pressure? like a gauge or something. also i was wondering if a injector lead having a short in it would cause the above symptoms?

 

How would the gear make a difference?

 

If it can't idle below 1800 it would have to be a huge vaccum leak. I would think the cas is stabbed wrong or something else major. Spark plug wires all good? good housings used?

 

does anyone know where that wire goes?

 

well it still refuses to idle! and i am out of ideas so does anyone know of someplace near or in longmont colorado that deals with rotarys?

 

Bumb

 

What should it be idling at if the idle speed screw is maxed out? Cause it is idling at like 1300 which according to rotary resurrection is fine for a fresh rebuild however if I completely let off the gas it dies. So could it be my tps or something?

 

What should it be idling at if the idle speed screw is maxed out? Cause it is idling at like 1300 which according to rotary resurrection is fine for a fresh rebuild however if I completely let off the gas it dies. So could it be my tps or something?

 

Well, what's confusing is that you say it won't idle below a certain rpm, but that's indicitive of a vacuum leak. The problem is that your car won't stay running below a certain rpm, it's not idling at all. That's probably not a vacuum leak issue now that I think of it. Remove L1 and T1 plug wires at the coils and see if it runs the same, then try it again with L2 and T2. That way we can see if it's running on one rotor. You could have a stuck seal that just needs to free itself up.

 

low compression

 

it wouldn't run at all if i switched the injector plugs right?

 

it straight up ceased tonight trying to pull start it! it locked up the back tires while it sounded like it was running i stopped and tried towing it home when it rotated again fine and would start but still not idle

 

maybe you put a rotor in backwards

 

like have the gear face not against the front or rear housing against the stationary gear? nah i dont suck that bad lol