Rebuilt motor starts and revs to 4k, is this normal?
Rebuilt motor starts and revs to 4k, is this normal?
So, I just finished the engine, primed it. And started it, its a bit hard to start (normal i guess) It revs to 3k then slowly goes up to 4k, it scared me so i turned it off, also it got pretty smokey. Is this normal? If not how or what can I do to prevent it?
1986 Rx7 NA rebuilt motor with Atkins rebuild gaskets and seals. Premix.
1986 Rx7 NA rebuilt motor with Atkins rebuild gaskets and seals. Premix.
The smoking didn't really bother me, I read that it's quite normal haha. What bothered me is it reving to 4k. After reading countless threads on break in procedures, it sounds like it's recommended that the first 200-500 miles aren't revved that high.
How do I control it through the Throttle body? The idle adjustment screw? will that really have an affect when it's revving through the roof?
I should mention, it revs to 3k quite fast with it in neutral (Accelerated warm up?) then it climbs to 4k quickly. It's a freshly rebuilt motor, so I'm afraid to damage something, I've started it a few times and it has done this each time.
How do I control it through the Throttle body? The idle adjustment screw? will that really have an affect when it's revving through the roof?
I should mention, it revs to 3k quite fast with it in neutral (Accelerated warm up?) then it climbs to 4k quickly. It's a freshly rebuilt motor, so I'm afraid to damage something, I've started it a few times and it has done this each time.
talking head
Joined: Apr 2008
Posts: 2,775
Likes: 15
From: Perth, WA, OZ
if it has all the AWS solenoids on it then it should rev to 3000 for 17 secs before ramping down to whatever the wax cam is currently at
if the engine is climbing further on revs then you need to look at the TB setup ( which should be unchanged if the setup was a previous runner )
and be sure the cable is on correctly and the throttle against the stop
look also at a sticky secondary throttle mechanism
if these are ok,, take a water spray bottle and spray around the join from LIM to UIM and especially the fuel injectors while idling
if you induce a stagger then you have a dodgy gasket or injector o ring
if the engine is climbing further on revs then you need to look at the TB setup ( which should be unchanged if the setup was a previous runner )
and be sure the cable is on correctly and the throttle against the stop
look also at a sticky secondary throttle mechanism
if these are ok,, take a water spray bottle and spray around the join from LIM to UIM and especially the fuel injectors while idling
if you induce a stagger then you have a dodgy gasket or injector o ring
if it has all the AWS solenoids on it then it should rev to 3000 for 17 secs before ramping down to whatever the wax cam is currently at
if the engine is climbing further on revs then you need to look at the TB setup ( which should be unchanged if the setup was a previous runner )
and be sure the cable is on correctly and the throttle against the stop
look also at a sticky secondary throttle mechanism
if these are ok,, take a water spray bottle and spray around the join from LIM to UIM and especially the fuel injectors while idling
if you induce a stagger then you have a dodgy gasket or injector o ring
if the engine is climbing further on revs then you need to look at the TB setup ( which should be unchanged if the setup was a previous runner )
and be sure the cable is on correctly and the throttle against the stop
look also at a sticky secondary throttle mechanism
if these are ok,, take a water spray bottle and spray around the join from LIM to UIM and especially the fuel injectors while idling
if you induce a stagger then you have a dodgy gasket or injector o ring
I had this happen to me my first go at a rebuild. I had something jam the throttle linkage holding it open. Look up my previous posts. Theres some good info in there from other members to track down a possible cause
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Tried to start today, didn't want to, de flooded it a few times and tried again. It was close! Tomorrow I'll try again after checking the spark plugs and recharging my battery (it died!).
there is a real they are telling you to let it run, it needs to wear in and gain compression. it usually takes tow starting them if you dont get enough compression to crank everytime..
Okay, so it doesn't rev to 4k anymore, which is probably a good thing. But there's a new issue.
Started it today, put a bit of oil on the plugs and it started right up. I had it running for about 20 minutes. It reved up initially to 3k, then dropped down to 1k, then the bouncing started happening. With my foot on the gas a bit it will still bounce as well, I kept the RPMS below 4k but no matter where I have the gas it bounces. I hope this is something as easy as the TPS. Anyways, video link is below. You'll notice the coolant cap is off, that's due to me filling and bleeding the coolant at the same time.
Started it today, put a bit of oil on the plugs and it started right up. I had it running for about 20 minutes. It reved up initially to 3k, then dropped down to 1k, then the bouncing started happening. With my foot on the gas a bit it will still bounce as well, I kept the RPMS below 4k but no matter where I have the gas it bounces. I hope this is something as easy as the TPS. Anyways, video link is below. You'll notice the coolant cap is off, that's due to me filling and bleeding the coolant at the same time.
Joined: Aug 2002
Posts: 2,614
Likes: 31
From: Freeland, MI
Sounds like you have a vcuum leak, get a friend to help you keep it running, take carb cleaner and spray all over the engine, when you hit a spot and the engine sound changes, than you found your leak
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