Engine wont rev more than 4000
 

Just bought a fd about a week ago knowing it didnt work hoping to fix it. The car will start and idle but it will not rev over 4000 rpms. i also have to pump accelerator for like 2 minutes to get it up there. if i press in the accelerator all the way the rpms will just drop and stall. Can anyone help me or maybe give me some ideas of what it could possibly be? all responses are very appreciated

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well since no one else has got to this thread yet.. i'll try to brew something up.

It would help to know though, milage? mods? other problems? (leaks, etc..)

I would check compression first. Search poor mans compression for rotary or something like that on google. Also check vacuum lines..
hmm.. injectors? could be spark plugs maybe?

I'm just rifling off things to get you started while other members are getting to it.
I would start by checking those things.. why not just change the plugs? it'll need it soon probably anyways.

By the time you've done that, you'll have alot of posts and help in here :nod:

Thanks for helping out. the mileage is unknown and the car is completely stock. i dont know how to check vacuum lines and ive already changed the spark plugs, sea foamed car, and changed fuel filter. do you think it would have to do anything with the fuel pump?

i don't think fuel pump.. however, I think right around 4k rpm is when the car switches over to the secondary injectors. I would look into that. Does it go past 4k on light throttle?

There could also be something happening with the ECU that rev limits it? Doubt it though if it's stock.

Checking vacuum lines can be tedious. I would say just hook up a boost gauge and if it boosts normally thats a pretty good sign but with this problem, you might have a tough time with that aha.

the only time i can get it up to 4k is on light throttle. but if i gas it all the way anytime im reving the rpms will just drop and sometimes stall. And if i would be the ecu what could i do about it?

How the hell did you just buy a car and NOT know the mileage???

I purposely set my rev limiter to about 3k whenever I put it into storage or let a stranger drive it (for shipping and stuff like that).

Are you sure this vehicle was aquired legally and honestly?

From what i understand the guy told me that he took an engine out of a jdm rx7 and dropped it in instead of rebuilding it. the car was only 5k and i thought was gunna be an easy fix thats why i thought it was a great opportunity to get an fd. how can i set the rev limiter

boost cut, fuel cut could be the only answer

Check the easy things first
If the car has the stock ECU and the boost sensor hose gets disconnected the ECU goes to "limp home" mode... Sounds like that might be your problem.

If it is only running on one rotor then the sound of the engine should be distinctly mess up.

where is the boost sensor hose located?

Its a little black sensor on the driver side firewall at the top

check your TPS sensor and check the vacuum line on te MAP sensor.

Where are all these sensors located? sorry im really new to all this

I just read a thread relating to the fc, the fd might be the same but the fact the it revs past 4k rpm on light throttle almost certainly (assuming it's set up the same way) indicated a problem with secondary injectors.. :scratch:

dude, honestly I would take it to a shop that can quickly diagnose the problem. If you don't know what your doing, you can cause other issues that will just put you in a bigger mess(if its not a big one already. Not saying that it isnt as simple as a vacuum line, but you need to at least understand or some what know where what goes where and is located or you'll be lost.

I had an issue with the first fd I ever had, the second turbo would never come on, 8 months later, it was a wrongly swapped vacuum line that I never would have realized if I never sat down and studied the vacuum line diagram.

Just saying...

well I had a similiar problem with my fd but my would only start up to idle and as soon as i touch the gas it would stal. I wana say i tryed it over 20 times on different days. One mechanic told me he thought my sencondaries werent coming on, one day i just kept messing with the gas trying to accelerate and it finally went through, so im assuming the secondaries were dirty or something.

and as for checking for vaccum leaks I know spraying carb cleaner to check for leaks you spray it around the hoses and it will stal it out or change the idle when it is sitting on idle if you spray a leak. BUT PLEASE BE CAREFULL CARB CLEANER CAN MESS UP YOU PAINT!!!!!!!!!!

the only thing I can think of , are the plug wires were swapped. Some one changed the plugs in his fd and it had the same problems, they apparently swapped around plug wires.. I cant remember if they swapped the leading front and rear are the trailing from and rear but when I checked it that was the problem... Check that.

so do you mean my leading and trailing might be mixed up?

Find the service highlights manual. It will show where stuff is and how some of the systems work, its good stuff and should help you out. Also take a look at the workshop manual.

Here is the link to the manuals

http://foxed.ca/foxed/index.php?page=rx7manual#thirdgen

If the lead and trailing was mixed up it wouldn't idle much more start I think.. I saying your leading and leading might be mixed up, or your trailing and trailing might be mixed up.

i thought both trailing plugs where the same?

supposedly, but i think it has something to do with charge time at the second burn of the rotor face??i could be talking rubbish here... not sure in that department but I remember switching either front or rear and the car was perfectly fine afterwards.

or it could have been to the wrong spark plug on the correct housing... Just check and make sure the trailing and leading go to the right housings and spark plugs.. you know which is lead and trailing right?

http://foxed.ca/rx7manual/manuals/19...al_systems.pdf

g20 & 21