hi, I just dropped in a new rebuild(my first time rebuild) into a s5 engine, everything is hookup right, and the car was started after couple cranks(not bad with first time. :-) )

I was so excited when I heard the noise. however, I quickly found out that it won't idle itself. once I let go with the gas pedal, it dies. I have to rev it up to 2500 rpm at least to keep it running. haven't check the compression yet. from the noise, I can feel that is very strong.

I know the engine has break in period for the first 500-2000 miles. is that what my problem is?. it needs to break in, and then gets idle? I read some posts. it seems some members got their new rebuild engine started and idle at >2000 rpm.

I can't drive the car for 500 miles without stop. should I just hold the throttle to 2500rpm for some hours? or should I check some vacuum leak first? I didn't use gasket marker for intake gaskets, cuz my friend told me not to. is that why? or it could be the old injector fittings?

thanks

 

Check the common problems .. leaks Etc. then just raise the idle till it idles. then start to lower it back as it breaks in.

 

check for leaks, if you cannot find any just wait it out... It's my understanding that some rebuilds don't want to idle when they first start up.

 

Its hard, but not impossible to drive if it won't idle.

When my engine first blew on me i had to get it home somehow. Its called heal-toeing. Its fun.

But aside from that just check for leaks and such, try to get it broken. If you don't want to drive it, then just get a brick or something to put on the gas pedal to hold the rpms where you want.

 

mine does that, i just rev it for a while than it'll idle perfectly, just keep revving it until it idles that's wat i do.................

 

yea check all the vacuum lines..is it a turbo II? check ur hoses on the intercooler etc.

 

I just got a new engine for my s4 tII. It started first try and idled perfectly once i tightend the throttle to keep it at 1500. The first 250 miles are tough, my car barely had any low-end and was hard to take off going up hill. Im at 2500 miles right now with the wastegate still wired open, it runs strong as hell im just waiting to get my walboro in the mail and then see how she boosts. Good luck with yours though, hopefully its something easy.

 

http://www.rotaryresurrection.com/break-in.html

Idle it up to 1500 and drive it as much as you can. THis is normal. After 1500 miles or so, go back and readjust idle and TPS, you'll notice it is much smoother and more powerful.

 

thanks for all the suggestion, guys.

I will try to keep rev it at 2500 rpm or whatever it takes to keep it run for some hours, and then see what happen. checking vacumm leaks maybe my last or last second thing to check.

right now, I only have the air pump belt on, nothing else. and that is a n/a engine.

will update you guys.
:-)

 

hi, I am going to work on the car tomorrow. before I go, I have a few questions for you guys

1)what is the benifit of drain out the old gas, and fill in with new one? what could happen if I don't?

2)obviously, I don't think that I want to drive car until it gets some idle. if the brake in is about 500 miles, how long do I need to keep the car running that is same as driven 500 miles?

thanks

 

88 TII

I almost have the same situation. Only mine will idle on it's own, but has a miss. It's an Atkins rebuilt engine, so I'm pretty sure the engine is fine. My dad says I have some wires crossed somewhere but from what I can tell, that can't happen. Mazda seemed to have put some thought into not putting identically shaped connectors right next to each other.

It took me a couple of days to get it started, and then I figured out the other plugs were fouled out. when i replaced the plugs, it started right up. when the throttle is held steady, there is a miss. but when i rev it, it revs smoothly and idles down smoothly and then misses again when i try to hold the throttle still. I've only ran the motor for about two 5-minute sessions. Was looking through factory service manual for possible causes for rough idle today and will go through the entire checklist tomorrow morning. There are no open vacuum ports but there is always a possibility for a leak somewhere. Most of the lines have been replaced. I couldn't find a matching size on some of the lines.

Stock intake, stock exhaust. However, the air pump is removed along with the BAC valve(i think that's what it is) and the egr is blocked off. There is also a homemade FCD installed but that was there with my old motor and it ran fine until it blew up(87K miles). Since the BAC and stuff has been removed, some of the vacuum solenoids are disconnected. All the metal tubing under the upper manifold has been removed to eliminate the now uneccesary vacuum lines. And I believe the last thing that I've messed with, the coolant line running into my throttle body has been removed/bypassed. So now I have to disconnect the thermo-wax dohickey so I don't have high idle for 20 minutes.

Is there anything you guys suggest I reinstall or check to fix this thing. I haven't been driving my FC since late April and I am so close to getting it back up and running. Ask me as many questions as you like.

 

hi, I worked on the fresh rebuild s5 n/a engine for few hours yesterday. it is alread dropped in the car. everything seems hooked up(but not sure 100%). I only attached the air pump belt, when I cranked the car, it started. and I tried to rev it for about 10 mins as kind of standard break in procedure(on and off). but I found couple weird things:

1)no stable idle(expected for new engine, OK)
2)it seems like there is a vacuum leak somewhere, cuz I heard some vacuum whistle from engine bay somewhere.(OK, check it later)
3)I noticed that when I rev the engine to keep it runs, all warning lights stayed on except the check engine lights. those lights should be off after engine start, if everything is ok.(STRANGE)
4)I heard the beep sound in the driver seat. that is not the warning sound to remind you the key still in ignition. it sounds like the warning when it almost reach the rpm limit. but the gauge shows that was only 3000 rpm. (I rev it always <4000 rpm)(STRANGE)

I am not sure about the warning sound caused by the warning lights or what. all gauge readings are normal. oil presure about 60, temp is good.

any one has suggestions?

thanks

 

it seems like there is a vacuum leak somewhere, cuz I heard some vacuum whistle from engine bay somewhere.(OK, check it later)

I had a similiar sound coming from the airpump hose that went to the acv. I chirpy continous whistle.
maybe you forgot this hose, it fell off or its damaged?

 

Fong, that's a dumb thing to do, start the engine and keep it running with only one belt on, and the least useful of them all might I add.

You at least need your alternator belt to be on as well. That is why your idiot lights stayed on. Anytime the alternator isnt charging properly, the lights are designed to stay on the whole time to let you know some **** is wrong. I bet the car didn't idle for **** seeing as how it was probably running on 11.5vdc or less.

As for the beeping, I think you're talking about the power steering ecu. IF you dont have that belt on either, it was probably complaining because it sees an engine RPM input from the tach, but the pump itself is not spinning. Again, take 5 minutes and put the friggen belts on the car before starting it again.

 

thanks, kevin. I will put all of them on to see what happen. I guess I was too eager to see it run.