81 RX7, 120k miles, automatic, newbie

About a month ago it got cold here and my rx7 decided to not start. I got a new battery and she started right up, once, and that was it. Now that I have time I'm starting to work on it. I've checked the forum and was working through the "No start" checklist. I was checking for spark from the wires and started at the top left, I think #1 trailing. I had the wire disconnected and checked for the spark and it started right up, ran rough for about 30 seconds and then she died. Started a couple of times more and died. But I hook back up that wire and it's back to just cranking. Does that sound weird or normal?

This makes me think it may be a timing issue if I understand these rotaries. I'll keep working through the checklist but I wanted to get this rollin first.

 

Make sure your wires are hooked up like this:

T1 T2
L1 L2

 

I think I've got them hooked up like that, but I'll check again.

I went through the no start checklist and everything checked out ok. I don't have a pressure gauge to check the compression, but it sounded good with a spark plug pulled. I'm thinking I'll rebuild the carb next and tweak it if I can. Any suggestions are greatly appreciated. Thanks.

 

How long have you had the car? Timing doesn't change on it's own so I see no reason to believe it has. Check the dizzy cap and rotor, clean the contacts/replace if needed. It's quite easy to bump the cap and knock it out of alignment, which then chews up the contact lugs in the cap.

If any part of the starting system was marginal when the weather was warm, those faults quickly show up when it turns cold. This includes the battery, charging system and all of the ignition components. Depending on how cold it's been, you may even have icing due to water in the fuel tank.

 

I bought the car mid-September from a mechanic that said the carb needs work because if you don't treat the gas pedal like a grandma the car dies dead. The distributor looks as though it's been adjusted in the past so that also contributed to my theory that the timing is iffy. I'll check out the cap and rotor. Thanks.

 

No reason for the carb to treated granny like. Sounds like it's time for a rebuild.

 

I was thinkin that too. Is the Sorenson rebuild kit still the way to go? Is there a walk through on the forum? I've got the carb manual pdf that was linked in one of the posts.

 

Sorenson is a good one so is the Standard sold through AutoZone.

 

Spark plugs tend to go bad on FC's for some reason i always have extra extra sets and on racing days even the extras have extras, try replacing them with some nice HKS or other high quality plug. this should help also the Oil in the Turbos tend to get cold and sit there so some times it take like 2 or 3 times of the engine starting and dieing to get that out .

 

I checked the spark plugs and they sparked ok. They're a Denon 4-prong type. I was thinking I'd replace them, but for now I got a GP Sorenson carb rebuild kit yesterday from AutoZone for $22. I'll start the rebuild tonight if I can.

I've heard good and bad about Chem-Dip: Good (gets it all off), bad (bad for you, eats you up). Is there a safer alternative. My first thought was to just use diesel, but maybe Chem-Dip is fine. I don't know. Suggestions welcomed.

 

Ive researched this problem also everytime its been low compression. Almost 99% of the time when the weather gets cold and the car doesnt start it means a bad engine.

 

Weird cuz my engine has 115 PSI on all faces and when its cold it doesnt start worth a damn and floods out constantly. Always has, even before I rebuilt it (to port it).

Edit: Chem Dip is good stuff but wear gloves or something.

 

Sounds like flooded engine to me, too...check out this thread..

A hard starting thread...

Mario III

 

Sounds like a carb issue.
Before you go too far, turn the key to on and go look down the throat of the carb. Do you see fuel trickling in (or pouring in ) to the engine?
Or it could be the complete opposite, as in there is enough fuel to start it, but the carb is too gummed up to let fuel be pulled in at idle.
Either way, I think you are on the right track.

 

So I've almost got the carb disassembled. One question is that the Sorenson kit said I'm supposed to remove (2) power valves (#62) and (2) gaskets (#63) for the power valves. My carb had a bolt there but no power valve or gasket in it. Is that alright?

BIG PROBLEM is I can't get the plug out that's on the Main Body of the carb. It's the flat head thats flush on top of the main body, #53 on the Sorenson list. I tried with the flat head and it's in there good. I stripped it a little trying to get it out. Any suggestions? Thanks.

 

The sorenson kit is for older and newer nikki carbs so some parts may not be used. It sucks I know. Not sure which screw youre talking about though so cant help there.

 

The screw I stripped is called the "check ball seal - accelerator pump inlet" and you can see it in the Carb manual that can be DL'ed from Sgt Fox's page:

http://www.wankel.net/~krwright/file...01979-1985.pdf

, part #71 on pages 49 and 50 of the pdf. Maybe the chem dip it's soaking in can eat it loose. We'll see.

 

Got it all disassembled and cleaned. That stripped screw succumbed to the soaking and gave way. We'll see what happens after the rebuild. Hopefully, we'll be running again.

 

Ok, I'm putting the air horn back on now, but one of the fuel inlet screws is not aligning and is not going in. Any suggestions? I've been trying to align it by hand or with clamps and it still aint goin in.

 

Carb is rebuilt and on the car. Now I have to pump the gas to start it, which I didn't have to do before. And I have to keep feeding it gas as it won't idle on it's own.

Question is how do I correctly adjust the idle? The manual says to turn the MAS or TAS until it's running at 750 or 840 rpm. Which do I do first?

Any help is awesome. Thanks.

 

did you check your starter motor? I'm having a similar problem with my mazda rx-7 -1st generation and planning to purchase a new starter.

 

Haven't looked at the starter motor yet. I got it started so I don't think it would be that, unless you know of a symptom I'm not thinking of.

I found the FAQ about the carb tuning. I put the TAS all the way in and the MAS all the way out and it started up, but unlike the FAQ I can't keep it running at less than 1000 rpm, so according to the FAQ it must be a vacuum leak.

Anyone know of a FAQ or walkthrough for a vac leak hunt? Thanks.

 

Thanks for your reply - I just joined and better understand the flow of the posting of threads and replies. I noted that you done a couple things to resolve the problem, but there are two more things I suggest you check as well I remembered when you mentioned the rpm

1: have you changed the fuel filter? I've had personal experience with this one also (rough idling)

2: there is a hose underneath the the blue item that holds the air filter that started to pop loose as a result of wear and tear - it's approximately 1-1.5 inches in diameter close to the engine side and firewall (car would start, idle roughly and then just stop until I reattached the hose.

Check those two items.

I hope you get resolution and one of these cheap fixes solves the problem

 

I haven't checked the fuel filter yet, but when I forgot I had the key on and disconnected the fuel line at the carb fuel was flowin pretty good. I'll look into that though.

As far as the hose goes, which one? There's one that you're SUPPOSED to disconnect and plug to tune the idle, the reconnect. That ones on the breather body at the driver side. There's another larger one on the front of the breather body and I think another on the far side (from the driver), about the same size as the first.

Thanks.

 

Go to the 1st gen section, and look in the FAQ section there. There is a nice writeup by Sterling on how to set the idle speed and mixture...



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