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-   -   79 problem car (https://www.rx7club.com/1st-generation-specific-1979-1985-18/79-problem-car-1106637/)

Taylor Freeman 10-20-16 12:28 PM

79 problem car
 
79 body aprrox 83 engine.. car has had trouble starting over the last 6 months... at first it would die while driving down the road, finally found that there was a ton of rust in the system.. had the carb rebuilt, still needs a little more adjusting on the floats. Red Koted the tank to stop any further rust issues replaced all of the hosing and flushed the remaining lines.

Replaced fouled out plugs as well.
at the start of the carb adjustment the car would not even get a hit from the plugs.. now that the rear float is at level and the front is kind of high the car will hit every so often when turning over but will not start, not sure if I need to overhaul the ignition system or not. had spark to the plugs using a tester.

just really at a loss at this point. Engine spins over fine and it will spit smoke every time the engine hits jut wont start. I am leary of using starting fluid since I am worried about damaging the apex seals. :confused:

andernamen 10-20-16 02:03 PM

First step is compression check. If the engine came out of an 83, it likely has high mileage on it. If that checks out, check your fuel pressure and go from there. You may still have carb issues despite the rebuild.

KansasCityREPU 10-20-16 02:05 PM

Check for vacuum leaks.

Taylor Freeman 10-20-16 04:48 PM

As far as the engine goes... it was supposedly rebuilt before it went into the car so around 50,000 miles on it. but ill check pressures on it. As far a vacuum leaks, there are no vacuum lines that i know of on it the rat nest and air pump has been deleted so there re no vacuum tbs running to the carb or the distributor.

KansasCityREPU 10-20-16 10:30 PM

A bad rat's nest removal can cause your issue also. Might want to post some pics of the carb.

Taylor Freeman 10-26-16 11:23 AM

I will do the compression test this friday. between 2 jobs and trying to build this and a motorcycle my free time is pretty limited.

Kansas I will post pics of the carb tonight, is there anything specific that i need to look for, are there some vacuum hoses that are supposed to be left on there.. car ran ok before the rust got to as far as i could tell, it definitely used to drop idle real low but rarely died, once warm it had no trouble running until the fuel problem. but any help and advice is greatly appreciated.

I am doing my best to justify repairing or rebuilding before i absolutely have to get rid of it or do some kind of engine swap to keep it

ROTARY_ADDICT-1 10-26-16 12:05 PM

check for vacuum leaks and then do a compression test

Taylor Freeman 10-27-16 12:38 PM

How do you check for vacuum leaks when the vehicle wont run, the only way i know is to have the vehicle running and spray brake clean on the intake and vacuum hoses

Taylor Freeman 10-27-16 12:39 PM

https://cimg8.ibsrv.net/gimg/www.rx7...6a02803627.jpg

https://cimg0.ibsrv.net/gimg/www.rx7...ff54006a87.jpg

https://cimg1.ibsrv.net/gimg/www.rx7...adedc2241a.jpg

https://cimg3.ibsrv.net/gimg/www.rx7...112b66b94f.jpg

https://cimg6.ibsrv.net/gimg/www.rx7...83bea5ab79.jpg

Taylor Freeman 10-28-16 07:32 PM

So new suspect... took the ignition leads loose and the coils are pouring oil out

Qingdao 10-28-16 07:42 PM

That's a lot of screws in those vacuum lines. But i'm not too sure that's your issue. You have fuel (plugs are fouled) so you don't need vacuum to pull fuel out of the carb. you've got plenty of fuel.

So you've got fuel; now you need compression. But you can rule out compression if you make sure you have spark. Which you have determined you don't have.

Shake the coils, if you hear oil rushing around inside they are probably good. If oil is leaking out of them its almost a sure thing they are inop.

Check the spark by laying the spark plug wires on a grounded surface. Stick some plugs in the wires. Spin the engine over and watch for spark.

Taylor Freeman 10-30-16 12:13 AM

adjusted the carb to the correct levels.. replaced both ignition coils. vehicle has spark but still not starting. looks like the carb may be done for... but even spraying some starting fluid into the carb it will get a hit or two but will not start. it started popping from the exhaust after a few attempts.... I am wondering if the apex seals are gone at this point. a complete tear down and rebuild seems to be in the near future, that and a carb replacement

t_g_farrell 10-31-16 10:35 AM

You really need to do the compression check before wasting any more time/$$$ on parts.

It could just be flooding our due to some carb issue or something.

Qingdao 10-31-16 11:36 AM

^ I second compression test

Taylor Freeman 10-31-16 12:08 PM

To do the compression test I just pull the lower plug I am test at and leave the other 3 in correct?

On a different note had one of my customers tell me that it was just flooded (which I hope is the issue since all of this started with the fuel system) and I needed to hook up a jump box and pour at least 3 quarts of trans fluid into the primaries and just turn the engine over until it started.... I saw an unflooding page that said to ass an oz to the primaries which i know using atf will help lubricate the rotor housing but 3 quarts?

Qingdao 10-31-16 01:09 PM

^^^^ NO

3 quarts = just under 3 liters... You don't even have that much displacement.

You compression test with all the plugs out. if nothing else it makes the engine able to spin faster. Also, if you keep the trailing in it has the possibility to fire you don't want that.

If you have low compression and want to run the engine you can use a little bit* of two stroke oil in the barrels to "diesel" start it. Another words adding compression beyond normal. I usually only do this if I've flooded the piss out of it, or if its a first start on a fresh engine.

BUT this doesn't solve anything its just a way to get a car started so you can get home to fix a problem with a REAL solution.

*little bit= two cap fulls

Taylor Freeman 10-31-16 07:56 PM

So compression test complete.... 3 testers later just to make sure, front rotor will not even bounce the needle, rear rotor bounces but doesnt even reach 30psi...

Qingdao 10-31-16 08:38 PM

Front housing & rotor are done. The rear will probably be fine.

Search for a used housing and rotor... Then use Atkins seals to get a good seal on your existing housings. It won't win races but you'll have a blast. :D

Taylor Freeman 11-01-16 05:54 AM

Damn that is what I was afraid of. I guess it is time to start over.. That engine was supposedly rebuilt before I got it with only 50,000 on it. The body only as 120,000 Guess it is time to rebuild and do it right

Qingdao 11-01-16 07:49 PM

50k is not too shabby for a backyard rebuild.

Taylor Freeman 11-04-16 03:48 PM

Well due to the lack of 12a parts that dont require a sacrifice to afford. I will be dropping the driveline from a mid 90s mustang into the rx until such a time that i can get or build a good rotor to drop in it as a drift or track car.

jeremyferguson4444 11-04-16 04:45 PM

^^^^ That's the best post I've read all day...but I doubt you will want to go back once you complete the swap :)

Qingdao 11-04-16 06:30 PM

mid nineties... Crown vic engine? booooo

early nineties.... 5.0 yaaaaaay


Why not just get a 13b? then you won't have to re-work your rear end.

Taylor Freeman 11-07-16 08:03 AM


Originally Posted by Qingdao (Post 12121609)
mid nineties... Crown vic engine? booooo

early nineties.... 5.0 yaaaaaay


Why not just get a 13b? then you won't have to re-work your rear end.

Well the plan is to get a 96 mustang gt. so I can have the 8.8 rear end, the tremec trans and the 5.0 which i will then build before putting it in.

Before I go back to a rotor I am going to dissect mine and inspect it and see what i can learn from it, I dont know nearly enough about rotors to fool with them too much sooo..... Its research and part hunting... but as far as reworking the rear end, both the trans and rear end in that car are worn out so bad. I would need to rebuild them anyways if not replace them.

Qingdao 11-07-16 01:34 PM

Begs the question; why not drive the mustang as is? Its not that much heavier than the RX7 and the only cool thing about owning an RX7 is telling people you know how to work a rotary. Besides the Mustang was built with that engine in mind. Seems like the hard way of going about things, swapping engines and the like. BUT in the end its your car or cars.


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