hornbm

Hey, my 85 GS is just sluggish. It has very little power. Pretty much seems like i've got an elephant sitting on the car. Interestingly, I cant get the thing to go above 4000 rpm IN FIRST gear! In neutral I can only get to 5000. Any Ideas to what might be wrong? I also hear a strange rattling in the rear of the car. Has anybody experienced this or know what i'm talking about?

Suparslinc

In this order:
#1. I'd check the anti afterburn hose that runs from the back of the carb to the lower intake, make sure it hasn't split.
#2. Dirty fuel filter
#3. Plugs, wires, dizzy cap - check for spark
#4. Have you lost compression? Pull off the plug wires, pull the bottom plugs out one at a time, and listen for a consistant whoosh whoosh as you turn the engine over.
#5. Clogged converters. The easy way to test this is yank the exhaust off @ the manifold and kind of prop it against the stud on the manifold. Start it up (it will be extremely LOUD) and see how it behaves then. I recommend a spirited drive down the street if you can get away with it and not **** off the neighbors/police.

I bet its one of those

hornbm

I may be pretty stupid for asking this, but where might I find this anti afterburn hose?

there is a grey looking tube comming from the intake components that has quite a few dents in it. is this it?

Suparslinc

Here ya go via mazdatrix...

http://www.mazdatrix.com/c-5.htm

the anti-afterburn valve hose is a fitted hose about 8-10 inches in total length. It runs from the rear of the carb and snakes through some other pipes and hoses into the lower intake manifold. Its proximity to the exhaust causes it to split or break near the bottom.

Its hard to see when looking down at the carb, and the bottom end of it almost disappears underneath the intake manifold.

RotorMotorDriver

iTrader: (1)

My money is on the fuel filter.

~T.J.

marshp

my car isnt sluggish at all, in fact it runs quite smooth and fast, however, i tried taking it to like 6000 rpm but it wotn do it, it just like stays at like a bit more then 5000rpm, why would that be?

Suparslinc

See above
I've recently been through what you are describing, and I'm repeating the help I got from others.

My big problem turned out to be something else entirely. But that was an unusual circumstance because I had my ACV apart last summer and did it to myself.

One reason you can't get above 5k might be stuck secondaries, but that is a little beyond my experience. Still learning about carburation...

hornbm

well i just realized i forgot an important detail. in adition to the low RPM in neutral, i couldnt get the car past around 30 MPH!

Pedestrian X

clutch? im thinkin cats.. but im no expert by any means...

hornbm

well heres an update. I have confirmed that I am getting spark from all four plugs. I was going to install the fuel filter, but the one I got looks nothing like the one allready on the car. I've heard people talk about there being 2 fuel filters on this car. Is this true. Where woudl the second one be? The one I'm looking at now is by the gastank and it looks quite dirty.

I feel like i might be getting on to somthing. Can anyone clear this up.

Oh and FYI I have an automatic transmission so I'm sure the clutch would have nothing to do with it.

Suparslinc

Thats the only filter. Some people install a second in the engine bay, which can cause a drop in fuel pressure and loss of power, but thats neither here nor there.

If you go to autozone/pepboys whatever they will have a parts catalog with the parts number for your fuel filter.

hornbm

Well heres somthing interesting.... Its a 85 GS, but right now as of when I bought it, it has a 79-81 style fuel filter! What the heck is going on?

Suparslinc

Mechanic said, keep the fuel filter and screwed a new car on top of it?

markrx7

You can order the fuel filters from victoriabritish.com. If you don't have one of their catalogs, you can request one for free from their website.

Pedestrian X

maybye iuf your lucky you will have a thermal reactor aswell hehehe

hornbm

well the filter didnt fix the problem and I have confirmed that the plugs are getting spark. Some one did mention that a second one could be installed... where would this be? The filter that I got (the 85 one) my dad says it looked like it was the type that go in front of the car.

Well, what next? Fuel Pump?

93 RX-7

For my two cents worth, I've had to replace the fuel filter three times and what you're describing wasn't it.

I've also replaced a couple of anti-afterburner hoses. That wasn't it either.

I'd bet that catalytic converter is clogged up big time. Second guess would be that your secondaries in the carb are not opening.

Good luck.

hornbm

Now I talked to my dad, and he sayed the secondarys are probably clogged because the car shuuter when u turn it off or somthing...................... but what my point is he said the the secondarys dont open untill you are allmost at full throttle, and should make a difference why I can't get above 30 MPH.

I doubt its the cat's because they were replcaced a few months ago. It was replace with a 2 cat setup instead of the usuall three. I think its pretty safe to say that that is not the problem.

Now could the secondary barrels be causing this? The discription i get from my dad is "its like driving with an elephant on the car" He also says it should have much more power right from the start.

So could it be the carb?

hornbm

i'm also thinking ignition timing, and fuel pump.

Update: i now know the secondarys are clogged, when ever you try to get around 4500 rpm the car shutters all over the place. It's obviously gummed up secondarys trying to open up.

But I still should have much more power from the start.... and the secondarys arent supposed to be open then

This is a bunch of pain just to get the car to pass emmissions.....

hornbm

just installed new plugs.... i can get up to high speeds somewhat... all the way untill the secondarys open up.

How ever it is still accelerating really slow. Any ideas for this one? I'm going to check the ignition timing tomorrow but could it be somthing else?

alien_rx7

Check your timing, especially if you've pulled the dizzy out anytime recently. I was replacing the rear igniter and accidentally knocked off the dizzy by one tooth. Talk about a car running like crap! It had absolutely no power afterwards until I figured out what had happened. And I replaced the fuel filter before I figured out what I had done, but at least the car actually seems to run a bit better than before, so either I got the timing a bit closer on (non-working timing light did not help) or the previous fuel filter was clogged. I'd vote for the fuel filter though since I just replaced my fuel tank the other day and found it had a nice rust hole in the top of it

hornbm

Well..... i just adjusted the timing and it was only off by 5 dergrees. Didnt seems to make much of a performance difference.

Today I had to go register the thing for the title transfer which ment emissions testing.

On its last test 2 years ago, it scored 8 hydrocarbons out of a limit of 220. SO in other words it passed with flying colors.

The results for today was 1120 hydrocarbons!!!! There is somthing serously wrong here.....