spla300

bought an rx7, any tips welcome

82 posts in this topic

http://irishrotary.com/forum/index.php?/topic/9024-new-member-from-longford/#comment-56614

Hi guys this is a continuation to the above link.

ive finally got an rx7, she dosent run, had a seized fuel pump, i fitted a good one and its pumping fuel also there is a spark but i dont know if injectors are firing i do smell petrol from exhaust though, i tried disconnecting power supply to fuel pump and cranking in case she was flooded but there are no signs of life.

there was an alarm which i removed, the original wiring was botched to get the alarm in.

the ecu is stock, has fancy blue samco hoses going to intercooler and a greddy metal intake thing on intake manifold, thats about it for the mods.

any ideas what else i could try? 

sorry photos wont upload the right way up.

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Where about are you based? I am no expert but spent 3 months trying to get my own one started. Was a bad ground causing that issue.

Happy to take a look with you if you are close to Cork.

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I think that one was bought in the UK recently and brought in. From the guys on the UK page, it was bought for £700 as it needs a full rebuild. Hopefully, they're all wrong but I suspect that you have more than a fuel pump issue there :(

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Im in longford,

i dont mind the rebuild might aswel start pulling engine out tomorrow then i was gonna rebuild it anyway just wanted to get her to fire up.

I will need complete wiring since the one in it is botched also need an irish shell with logbook, the older the better, vrt will be pricey im sure.

Rex Ruthor likes this

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VRT is about ~€1500 give or take on a 1993.

Have you tried compression-testing it? From the video that the previous owner posted up it sounded like it was low on compression in at least 2 chambers on one rotor.

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a2c637131945b537c94bf7ea69018f2c.jpg47f7e983e49fffb6a1dea7b46ebf839d.jpgd06906f55c28b92af9c5e90616a18966.jpg58425059ad217915aa97730caee2693e.jpg3a91b9dcbca7e1489fa36e4a05e987b9.jpg
Can anyone tell me what that thing is in the last pic, it's plugged into air intake.


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Pricey, how much is a bare metal shell with logbook?. Are all the engine looms and ecu's the same across all fd's? Can they be mixed and matched?
I've decided to just start stripping her and do the rebuild.


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VRT is about ~€1500 give or take on a 1993.

Have you tried compression-testing it? From the video that the previous owner posted up it sounded like it was low on compression in at least 2 chambers on one rotor.


Would you have a link to that vid??


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That would be the air pump. It pumps air to the exhaust pre cat to reduce emissions. It operates at idle and low rpm. It can be deleted but ideally u would need an idler pully kit for correct belt tension 

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I'll Defo have to take it off then thanks.
Anyone got tips on pulling engine out?
What to watch out for?
I'm guessing mounts have to be loosened from under the car I can barely see them from the top.


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15 hours ago, spla300 said:

Pricey, how much is a bare metal shell with logbook?. Are all the engine looms and ecu's the same across all fd's? Can they be mixed and matched?
I've decided to just start stripping her and do the rebuild.

They don't come up all that often but if the shell you're using is rust-free, I'd just pay the VRT & save yourself the time/hassle as it's a lot of days work transferring over an entire car's components.

No the looms etc are different across different years & markets - the loose breakdown is as follows: 91-95, 96-98, 99+. If you want to know more do a search on here; there's also the RX7 FAQ section which has a load of articles on different aspects of the cars so that should help a fair bit. ;)

15 hours ago, spla300 said:

Would you have a link to that vid??

It's in the "RX7/RX8 For Sale" Facebook group where it was last for sale about a month back, the previous owner from Northern Ireland posted it up before it sold.

If you've not removed the engine already yourself take a vid & post it up - it'll help confirm the diagnosis rather than going stripping the engine potentially unnecessarily. Before that again unless you're confident that the compression is down I'd strongly recommend a compression test. ...Unless you're going to pull it out & strip it down anyway for the experience but if you do & compression wasn't the issue then when you piece the car back together you'll likely have the same problem waiting for you when the engine's reassembled.

Aido 8 likes this

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Thanks for all that info.
I was originally looking for one with engine trouble just so I can rebuild it. I'm In the process of taking out the engine I plan to bridge port it for some brappage and I wanna raise oil pressure to raise rpm.
Where would be the best place to get apex seals?
Also could I not just get 99+ wiring and Ecu which will also give me obd2 ?
Would injectors be the same and other electronic components?
Would engine run with 99+ wiring and Ecu?


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a2c637131945b537c94bf7ea69018f2c.jpg47f7e983e49fffb6a1dea7b46ebf839d.jpgd06906f55c28b92af9c5e90616a18966.jpg58425059ad217915aa97730caee2693e.jpg3a91b9dcbca7e1489fa36e4a05e987b9.jpg
Can anyone tell me what that thing is in the last pic, it's plugged into air intake.


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I think you are asking about the air pump. It's only job is to pump hot air into the cat at low rpm to keep it warm to improve emissions.

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Rotary are emissions exempt in Ireland So pulling the airpump is fine but expect a smellier exhaust. More of a problem for the people driving behind u :D

The air pump doesn't heat the cat, accelerated warm up was for that. It gets a cold feed from intake to supply oxygen to the cat to help burn nox and hydrocarbons.

From your pics I'd change plugs as it looks a bit worn so no harm. And your EGI relay is damaged, probably from people pulling it trying to unflood the car. It's the yellow one so make sure it's working or u won't have fuel.

Not sure how hard it would be to change to 99 spec harness and ecu but I'd say there would be a lot of splicing. The rats nest is different, ud need a 16 bit abs pump. Uim is slightly different but shouldn't be a problem. could have problems with some sensors and the exciter unit maybe.

So just get a PFC, u can read sensor voltages from it. more power and up the boost with a boost controller. Don't think the PFC sounds the low coolant buzzer though.

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Right Defo getting rid of air pump and the ac.
Yeah I'll get new plugs.
It's only really the cover that's damaged on the egi relay the relay itself works.
I'll do more research on harness thanks.
Should I just buy apex seals on eBay?
Is there a certain brand ones I should buy?
Or should I keep away from eBay?



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Stock seals are good up to mid 3 hundreds hp levels. Their strong and have the best wear characteristics for your housings. Problems being they chip and shatter with knocking but with a good map I wouldn't worry about that and they withstand knocking better than most seals out there. Above that I would use RA super seals and solid corner seals with the porting u plan on doing.

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If you are doing a full bridge engine you will need single piece apex seals.

2 piece will work with a half bridge but they have to be installed differently to the fsm. 

If you are bridge porting it won't run with a standard ecu. idle will be 1500rpm+.

You will need to have the rotors lightened and clearancedo if you want to run higher rpm or you will get rotor slap. 

A bridge port with a higher rpm limit will need a big single turbo. this will also-ran  mean a fuel system upgrade.

Vrt will be cheap compared to the rest of the work.

 

jp and Aido 8 like this

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http://www.mazdarotary.net/porting.htm
Thanks for all that info Just had a look at that link aswel and reconsidered the bridge port has late power pick up mild port and extended port seem to look like they would be better for road use but why do they say 200bhp and 220bhp? Aren't them engines 250bhp at least??
Would any engineering shop be able to lighten rotors?
Would a single bigger turbo be better than the stock 2?
What max Bhp can be gained from the stock 2 turbos?
I rebuilt an mr2 from ground up had the bare metal shell resprayed and engine rebuilt and got 400bhp I plan to do the same with the rx7 and since I'll be stripping her either way so I might aswel just find an Irish reg shell. Also upon closer inspection looks like she's been crashed from both ends before and it's not something I like.


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On 11/17/2016 at 2:11 PM, spla300 said:

Thanks for all that info.
I was originally looking for one with engine trouble just so I can rebuild it. I'm In the process of taking out the engine I plan to bridge port it for some brappage and I wanna raise oil pressure to raise rpm.
Where would be the best place to get apex seals?
Also could I not just get 99+ wiring and Ecu which will also give me obd2 ?
Would injectors be the same and other electronic components?
Would engine run with 99+ wiring and Ecu?

Nay bother. ;)

Start with the sticky thread in the General section on the forum listing the National & International rotary parts shops. ;) Mazda Japan if all else fails.

As Laned3 said, there are a lot of differences in the wiring/ECU, nevermind the other components that plug into the ECU. Unless you've some burning desire to upgrade every component to a 99+ spec (in which case you're better off starting with a 99+ car) or want to spend a fortune in cash & time doing it, then I'd suggest sticking with the components that are matched to your model-year; plus there is more detailed technical information freely available for the earlier models than the later ones (not that it's impossible to find, just that a lot of it is in Japanese).

For porting etc, you'll need an aftermarket ECU anyway which will likely negate any benefit you'll get from having OBD2 in the car.

On 11/18/2016 at 1:42 PM, spla300 said:

Right Defo getting rid of air pump and the ac.

Should I just buy apex seals on eBay?
Is there a certain brand ones I should buy?
Or should I keep away from eBay?

From my experience with my own FD, given how hot the interior of the FD can get & that was a relatively stock car, I'd keep the aircon.

Depending on your power/boost goals, you might be as well off looking at uprated apex/side seals from (as Laned3 said, "RA"/Rotary Aviation; Goopy; etc.) - again start in the parts websites sticky I mentioned above. It's the quality of the components that matter, not where you buy them.

On 11/18/2016 at 7:34 PM, spla300 said:

http://www.mazdarotary.net/porting.htm
Thanks for all that info Just had a look at that link aswel and reconsidered the bridge port has late power pick up mild port and extended port seem to look like they would be better for road use but why do they say 200bhp and 220bhp? Aren't them engines 250bhp at least??
Would any engineering shop be able to lighten rotors?
Would a single bigger turbo be better than the stock 2?
What max Bhp can be gained from the stock 2 turbos?
I rebuilt an mr2 from ground up had the bare metal shell resprayed and engine rebuilt and got 400bhp I plan to do the same with the rx7 and since I'll be stripping her either way so I might aswel just find an Irish reg shell. Also upon closer inspection looks like she's been crashed from both ends before and it's not something I like.

Your porting should depend on what power goal you have, and your turbo should always be matched to your porting & vice versa: there's no point in having a great big turbo with ports that are too small or a full bridge with a smaller single.

The page is referring to N/A power, not turbo - note the references to older rotary engines & 13B turbo engine conversions.

The engineering shop needs to be able to balance a rotary rotating assembly which is very different to an otto-cycle/normal piston engine rotating assembly in design in order to be able to balance the lightened rotors correctly.

Single turbo is a simpler setup than the stock twins (removes the need for the "rats nest" of vacuum pipes & solenoids, etc; declutters the engine bay; etc), but "better" is subjective to what you want out of it: some singles can spool as quickly/more quickly than the stock twins & give more bhp but won't be as progressive, etc etc - how much you want to spend on a turbo setup will likely factor here. Do some more reading on the merits of both - it's likely covered somewhere in the RX7 FAQ on here.

Max bhp from the stock twins is somewhere around ~350bhp at the fly depending on supporting components. You can get uprated twins (e.g. Famspeed, Knightsports, Mazda RX7 SP turbos possibly) that'll flow a little more & possibly hit 400bhp+.

Ask @shane - I think he came across a breaker recently in the midlands with a black FD shell, not sure if it was on Irish plates though. It might be worth posting up a "Wanted" ad in the for sale section here stipulating what you're after.

 

What exactly is the car going to be used for? Is it going to be a daily driver/track-only/mostly one or the other? Is there a power figure or driveability goal you want from it? And do you have a budget to stick to?

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Thanks that's a lot of useful info. Yeah I'll most likely be going apexi standalone so might aswel make an attempt at fixing that botched up wiring. It's damaged around the ignition where alarm was installed and down at the Ecu as if someone tried splicing a piggyback into it.
Yeah I'll do more research on apex seals when I get my rotors out I'm seeing some say 2mm and 3mm I've no idea what size I need yet.
350-400bhp sounds good to me, she will be a weekend car for road use.
If I can get nearly 400bhp with stock turbos then I'll just keep them I suppose. I'm sure meth injection will help get the numbers up.
I have an engineering shop nearby I can ask if they work with rotors if not I'll ask Martin Tracy in Enfield.
As for budget I suppose I can save and spend what needs to be spent over the winter months hope to have her for summer.
Thanks I'll ask Shane. I rang a breakers on Donedeal breaking a couple rx7's his prices are kinda steep...


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Happy to help! :)

Typically they'll be 2mm - it's only if the rotors have been machined top accept 3mm that they'll be 3mm - there's no real advantage to the 3mm either for most applications, again more to read up on.

You'll be pushing it getting anywhere near 350bhp even with all the gubbins & possibly assuming you've a ported engine - not sure how long they'll last either so were it me, to make it reliable & hit the power comfortably I'd suggest looking into single turbos. e.g. GT30R or GT35R or newer equivalents if they're not too much in the different price-wise.

Shop around when it comes to breakers, prices can be far & wide with these things. If you can find a private individual even better! ;)

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