jackofalltrades

I have a 1984 GSL-SE since 2000. It's stock, nothing modified, and has the original 13B engine. Until a couple of years ago I had been using it a lot but then I put it to the side when I got my 2nd car.

Here's my problem: I can hear a loud sucking sound of extra air coming into the engine and it's reving way higher than it use to (2000+). It seems to be running lean.

The problem started with I noticed raw fuel dripping from the engine near the injectors and did some repairs to deal with that issue.

I took apart the engine, sorry but I don't have my Hanes manual with me to use the right terms, and traced the problem to a small fuel lines that runs from the gas inlet accross the engine and connects to the fuel injectors.

Unfortunately, I made the bad decision of changing the injectors with an existing older set to make it easier on myself replacing the lines but ended up getting leaks but from the injectors themselves.

Eventually, I got that problem licked. Thereafter the sucking sound could be heard loud and clear as I tested the moto.

I'd appreciate any and all ideas leading to the cause and how to cure it.

trochoid

iTrader: (6)

If this was the first time the injectors were taken out, then they need a fresh o-ring kit. While they're out they should also be sent out for cleaning and calibration. Since removing them requires the TB, DC, and UIM to be removed, this is also a good time to replace those old, hard and rotting vacuum lines. I'll venture an educated guess that the leak was from a faulty Pulsation Dampner. Quite common in both the 1st and 2nd gens. There is no repair for the PD, only replacement with a new one or substitute a banjo bolt in it's place.

The following links are to the online FSMs, much better than the Haynes.

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

http://www.wankel.net/~krwright/cars/rx7/manuals.html

You have a vacuum leak somewhere, that's the loud sucking sound and cause of the high idle. Cause could be a bad gasket, bad vacuum hose or you missed reconnecting a vacuum hose. To help chase down the leak, buy a can of carb cleaner that has the spray straw in the nozzle. When sprayed close to the leak, the idle will change.

jackofalltrades

> Posted by: trochoid
> If this was the first time the injectors were taken out, then they need a
> fresh o-ring kit.

Yup, that was done.

> While they're out they should also be sent out for
> cleaning and calibration.

I can't say if that was done or not.

> Since removing them requires the TB, DC, and UIM
> to be removed, this is also a good time to replace those old, hard and
> rotting vacuum lines.

Dumn question but are you talking about the cluster that comes out between the plenum and the alternator?

> I'll venture an educated guess that the leak was
> from a faulty Pulsation Dampner. Quite common in both the 1st and 2nd
> gens.

Actually, it was a rotten fuel line. But now that I'm aware, I'm going to watch out for that.

> The following links are to the online FSMs, much better than the Haynes.
> http://foxed.ca/foxed/index.php?page=rx7manual
> http://www.wankel.net/~krwright/cars/rx7/manuals.html

Much appreciated thanks! :-)

> You have a vacuum leak somewhere, that's the loud sucking sound and cause
> of the high idle. Cause could be a bad gasket, bad vacuum hose or you
> missed reconnecting a vacuum hose.

I'm leaning towards the missing/damaged vacuum hose theory at this point.

> To help chase down the leak, buy a can
> of carb cleaner that has the spray straw in the nozzle. When sprayed close
> to the leak, the idle will change.

Is it possible that there could be a damaged or missing vacuum hose below the plenum? Is it even practical running the engine and testing using the carb cleaner by spraying the various connections etc.?

trochoid

iTrader: (6)

DC, Dynamic Chamber. the large rectangular looking box on the top of the engine. TB, Throttle Body, bolts to the DC, this is where the accelerator and cruise control cables connect to, along with the large black tube from the air cleaner. UIM, Upper Intake Manifold. This is the part that the DC bolts to, which then bolts to the LIM, Lower Intake Manifold, which then bolts to the engine. The 'cluster' is generally refered to as the 'rat's nest'. The plastic barbs on those solenoids that the vacuum lines connect to become brittle with age and can easily crack or break.

If you can get the engine to start and run, then by all means run the engine to try and find the vacuum leak. As to where the leak is, it could be anywhere, bad gasket, bad/missed vacuum hose or even a bad injector o-ring seal.

If you found one rotting fuel hose, replace all of them for safety's sake.