hi there and oops think I have bought a lemon

[123tom123tom]

car spec:
1993 rx7 twin turbo
twin filters relocated in bumper
full decat exhaust (super drager)
mines ecu
greddy boost meter and gauge
(maybe not sure but was told) Walbro 255 pump
 
that is it as far as I\'m aware!!
 
First off hello everybody,
 
I bought a mazda rx7 the other day as a spare of the moment thing. I love the car the way it looks and drives, (kind of).....
 
I will tell you the problems that it has:
 
- there seems to be a bad earth on the car when you put everything on, like the radio, heater fans and lights the car runs lumpy at idle, jumps between 650 and 800 rpm. Soon as you turn everything of it runs quite steady at about 750rpm.
 
- it seems to be using a little bit of water, not 100% on that yet?
 
- BLUE SMOKE some times it isn\'t there but most of the time it is, seems to be worse when warm, notice it more when de-accelerating.
 
- last problem for now!!! the car does not like high rpm whilst under load?, it will rev on the spot.... but 4k and above on boost the car sputters and back fires like crazy, very loud and judders??
 
If it helps I am a mechanically minded so I can get my hands dirty :Tongue1
 
 
Thanks in advance (please go easy on me I am new :Thumbs-up )

[rising son]

hi mate , new to these cars myself. but for problem 1 possible a grounding/earth kit could help you out.
as for the last problem, maybe overboosting and hitting fuel cut, or plugs missing under load, or possible even a fuel pump issue.., im sure somebody with a bit more experience will help you shortly

[123tom123tom]

hi mate , new to these cars myself. but for problem 1 possible a grounding/earth kit could help you out.
as for the last problem, maybe overboosting and hitting fuel cut, or plugs missing under load, or possible even a fuel pump issue.., im sure somebody with a bit more experience will help you shortly

 
hi there thanks  for the info, I was thinking very similar on the last issue, fuel related or fuel cut??? can any one tel me when fuel cut kicks in on these also it has aftermarket ecu thought they would have mapped it out??? it is currently hitting about 1 bar of boost but drops quite a lot as the second turbo tries to come on line... I say try because it missfires that badly and stutter/splutters it cant boost really?

[shaunwil]

They could be minor issues so hopefully they can be easily fixed.

On the water front check nothing is actually leaking. The waterpump will leak to warn you the bearing is on the way out. Are you seeing any overheating issues (such as the fans kicking in a lot ?) If you can\'t find a leak then it could be more major. Do a search for the champagne test. This will tell you how to check the engine for a waterseal failure.

On the oil front it could be the bearing in the turbo is on its way out. 2nd hand turbo packs do turn up and its a rather fun job to swap over.

The spluttering can be caused by the vacuum lines splitting and the one way valves degrading. Do a search for rats nest to see more details.

On a grounding note just check all the grounding points are clean in the engine bay. The idle rpm does change when you put electrical stuff on and it depends on what is on the piggy back chip ecu has been programmed to.

Hope this helps !

Shaun

[123tom123tom]

They could be minor issues so hopefully they can be easily fixed.
 
On the water front check nothing is actually leaking. The waterpump will leak to warn you the bearing is on the way out. Are you seeing any overheating issues (such as the fans kicking in a lot ?)
 
----fans arent kicking in a lot only when stood in traffic as you would want them to, no over heating at all? there seem to be water on the slam panel area every time I open the bonnet think it is coolant but cant locate where it comes from-----
 
If you can\'t find a leak then it could be more major. Do a search for the champagne test. This will tell you how to check the engine for a waterseal failure.
 
On the oil front it could be the bearing in the turbo is on its way out. 2nd hand turbo packs do turn up and its a rather fun job to swap over.
 
-----This is the route I think I am going down, the over fueling/back firing etc at higher revs from 4000 rpm upwards is when the second turbo should be online.... I think it is failing causing the above to happen i.e causing the car to run rich because the air isn\'t there from the turbo? thats my theory------
 
The spluttering can be caused by the vacuum lines splitting and the one way valves degrading. Do a search for rats nest to see more details.
 
------ any particular pipes/valves i should be looking for(more to do with second turbo I surpose)-----
 
On a grounding note just check all the grounding points are clean in the engine bay. The idle rpm does change when you put electrical stuff on and it depends on what is on the piggy back chip ecu has been programmed to.
 
-----It has complete stand alone MINES ecu on the car?? (maybe a remap is needed)----
 
 
Hope this helps !
 
thank you again kind regards tom

[rx7boy]

Coolant in slam panel area would indicate that the AST (air separation tank) has a split

The mines ECU cannot be mapped here in the UK, that i am aware of anyway.

Get a ground kit anyway even if the stock points are ok (ebay)

Boost wise, check all your intercooler lines are tight and split free. If they are all ok then you need to start looking into the vac/pressure solenoid system under the inlet plenum, commonly known as the rats nest. Search here for the diagram, but you might find it a ball ache so better to take to a specialist.

I would also consider getting a different ecu, the mines one will be mapped to Jap fuel 102 octane and during these colds months you might find the car will run lean and pop due to pre-ignition.

Plug and play ecu\'s are Apexi pfc or Link plug in units

[123tom123tom]

Coolant in slam panel area would indicate that the AST (air separation tank) has a split
 
The mines ECU cannot be mapped here in the UK, that i am aware of anyway.
 
Get a ground kit anyway even if the stock points are ok (ebay)
 
Boost wise, check all your intercooler lines are tight and split free. If they are all ok then you need to start looking into the vac/pressure solenoid system under the inlet plenum, commonly known as the rats nest. Search here for the diagram, but you might find it a ball ache so better to take to a specialist.
 
I would also consider getting a different ecu, the mines one will be mapped to Jap fuel 102 octane and during these colds months you might find the car will run lean and pop due to pre-ignition.
 
Plug and play ecu\'s are Apexi pfc or Link plug in units

 
the car has a aftermarket ground kit on it already and a new battery? also the alternator is putting out just over 14 volts, when i check the recharge on the battery it is 13.9v so only a slight drop, but this drop causes it to idle a bit lumpy... if I turn everything off the car runs better and the volt across the battery raise from 13.9 to just over 14 again?? Think the grond kit needs cleaning up..
 
I was talking to a company in the uk local actually who said they could map the ecu so I have solved that one lol.
 
Intercooler pipes are all good by the looks and feel. So looks like I will have to look at the dreaded rats nest. Any idea where to start and how to test maybe?
 
Is there any rx7 specialists on here that are near me?:driving

[lennycarloff]

Hi there you have mx5 motors (hayward north) in doncaster,hope you can get it sorted

[123tom123tom]

Hi there you have mx5 motors (hayward north) in doncaster,hope you can get it sorted

 
thankyou will check them out
 
regards tom

[123tom123tom]

right had a drive in the rx today again, I have noticed a few more clues to help diagnose the smoking problem?
 
When I started the car this morning no smoke just a bit of condensation. When the car is warmed un it then begins to smoke lightly at idle (blue) and smells of oil, when you drive the car off of boost it smokes enough to see through the rear window? When you pull up at a junction you will see a big bloom of smoke as you pull up then it dies down a little?? You can smell it in the car really bad.
 
When you boost the car it runs about 1 bar up until 4000rpm then the cars splutters and back fires and the boost drops as a result of this.. It is like the second turbo isnt coming online at all??? but I wouldnt no as I have never owned one of these.
 
There is some pipes blocked off under the bonnet, two big ones that are next to each other above the turbos? and i had a very brief look under the inlet manifold, didnt take off just peered underneath.. I noticed some hard litle metal pipes that had no silicon pipes on them??? Dont know if there is some kind of MOD been done to the car??
 
Sorry for the long story just trying to love my car and get to the bottom of its smokey and backfire problems :Tongue1

[Brett]

Sounds like someone may have tried to make it non-sequential.

Given the amount of smoke I\'d imagine you have at least one knackered turbo... is it using a lot of oil?

[123tom123tom]

T

Sounds like someone may have tried to make it non-sequential.

Given the amount of smoke I\'d imagine you have at least one knackered turbo... is it using a lot of oil?

It does not seem to use any oil, but definately is oil out the exhaust just doesnt seem to be using much even though it stinks of it

[RobMatthews]

Unfortunatly until you know what your really looking at and how the car should behave its gonna be very hard work, it may be simple and easier to get it to a specialist or someone local to you with one to compare?

Not all the small hard vacuum pipe are used in japan/uk. so some would be unused, places like canada/usa had slightly different set-ups for things such as emmission control/altitude/climate etc

Have you had a look in the i/c pipework and i/c to see how much oil if any is in there? If its lagged, it would suggest a problem with turbo seals.

[wolfie1]

have you tried changing the fuel pump cause that can give the symptons your experiencing at that rpm, mine did

[123tom123tom]

Unfortunatly until you know what your really looking at and how the car should behave its gonna be very hard work, it may be simple and easier to get it to a specialist or someone local to you with one to compare?
 
Not all the small hard vacuum pipe are used in japan/uk. so some would be unused, places like canada/usa had slightly different set-ups for things such as emmission control/altitude/climate etc
 
Have you had a look in the i/c pipework and i/c to see how much oil if any is in there? If its lagged, it would suggest a problem with turbo seals.

 
hi there checked the ic piping not one sport of oil, but ami right in thinking that the hot side could have oil leaking causing the smoke, then the oil wouldn\'t be in the ic piping??? might be wrong on that though... will check the fuel pump and filter tomorrow see if there is anything there a miss.