I\'m now going to remove the tank to give it a good clean, I have read the Haynes manual on removal, any tips on this or is it as straight forward as they say...........off to football now so will not be back for awhile. :WaveBye
not sure what it says in the manual but its a fairly easy job, there is a drain plug to make things easy, remove all the cowling, open the petrol flap undo the 2/3 screws around the filler undo the tank straps i usually lay under the tank to take the weight or you can just use a jack with some wood on it, disconnect the lines and your done
Get a couple of spare 5litre petrol cans before starting. Tesco is good.
Once you have got the tank out you probably want to access the dip tubes by removing the plate they go through. Unfortunately the screws may not be too forgiving. The sender unit plate is far worse than the dip tube plate (mine were bloody rusted solid on the sender system). Needed to be drilled out and new ones put in. Also gaskets are fairly thick and may need renewing if they break up. If you just want to get into the dip tubes and the gasket stays intact you may find it\'s all straight forward.
But have your workmate bench and small pilot drills ready if not.
Only issue I had with mine was the bolts where rusted to death !
Plus there is usually a lot of spare fuel in the tank, make sure you have enough bottles when emptying it !
Shaun
Before you go to the trouble of dropping the tank, why not just put a can of clean fuel connected directly to the line in of the fuel pump. You can use an ordinary 5 litre fuel can.
If it solves your running problem, then you know its a feed problem tank side of the pump. If not, then the problem is engine side of the pump.
How confident are you of the carb rebuild? If it revs to 5000 ish but no further, could be a problem with the secondaries or the accelerator pump.
Thats a very good point. When mine didn\'t rev past 5k it was down to a fault with the trailing pick-up on the dizzy !
Shaun
Hi Guys and thanks, just got back from Footie and we won 0-5.
Ian it revs to 5000/5500 if you feed the pedal slowly, if you floor it it will cough and fart, when I put it on the trailer to bring it home today, it only got up half way, not having enough power to make the rest and had to be winched up. When it is on tick over, and the engine has warmed, it seems to be hunting all the time.
I was thinking of trying running from a can via the pump as you suggested, so will try this before I remove the tank.
Thanks to all
Dibs
Quote from: Ian65;649894Before you go to the trouble of dropping the tank, why not just put a can of clean fuel connected directly to the line in of the fuel pump. You can use an ordinary 5 litre fuel can.
If it solves your running problem, then you know its a feed problem tank side of the pump. If not, then the problem is engine side of the pump.
How confident are you of the carb rebuild? If it revs to 5000 ish but no further, could be a problem with the secondaries or the accelerator pump.
Wow, that is smart thinking. Obvious I suppose but I wouldn\'t have thought of it. And the return line just stays in place, spare fuel just being returned to the tank.:yes
Double check of dizzy/vacuum mechanism? This is gonna be a killing thing when you find out the problem..
Forgive me here ....I\'m trying NOT to be a smart arXe NOR to send you down a blind alley.
But hunting at idle suggests a number of things to me not linked to fuel delivery from the tank.
First up timing - distributor and electrical, Second manifolds (gaskets, cracked manifold), Third internal water leak from O rings in the intake gasket system - common failure with age. Then vac lines, servo connections etc. Blocked air filter - too obvious?
The O ring thing usually shows as a ponding of antifreeze in the manifold hollows back of the carb, but it could be internal only.
If you\'re satisfied with all the above then back to the fuel system/carburetor.
Another source of ideas would be RX7Club.com in the states. They have a biggish 1st Gen section.
It could be any number of things really but fuel and ignition are the favourites.
My moneys on fuel though.
If Dibs bypasses the tank, etc and still gets no joy then I would then check the tiny fuel filters under the fuel union bolts where the fuel lines bolt to the carb.
They are no bigger than a finger nail and sometimes get missed but are so easy to clog.
They will pick up debris that sails through the main fuel filter.
If they are clear, I\'d get it ticking over, rev it up and check the fuel levels in the front and rear fuel sight windows on the carb.
These should remain about 1/2 full. If they don\'t then I reckon it\'s a carb / fuel delivery problem. A volume / pressure test will eliminate the fuel delivery to the carb which then leaves the carb itself.
Of course, it could always be the ignitors, dizzy, leads, etc ...
It still sounds like fuel starvation to me though.
Thanks and watch this space, I wish you guys lived nearer...............
Yeh, if we were nearer we could pop round to yours for a coffee/beer and a looksee.
I like Ian\'s approach to the sight glass on the carb - a steady fuel level in there whilst on tickover and still hunting means it\'s unlikely to be anything before the carburetor causing the hunting.
The carb mixture and idle adjust screws are set right I take it..RECALLING FROM MEMORY....set up to a fast idle speed, turn mix screw in until it starts hunting, back off mix screw a tad and reset idle speed to normal. I think that\'s it. That blessed manual might have to come out of the cupboard again so\'es I can recheck.
Right this morning I tried Ians idear, running from a can striaght to the pump, no change, so no longer going to remove the tank.
I was running it this morning from both the tank and can and it was reving up to 6000 and then dying sometimes could catch it and keep it running other times it would conk out. Took the air filter off and two pots of the carb closest to the wing were full of fuel, and the other two were misting, thats when I felt I was getting in to deep so came on here....................help.......
Ps when it was running when warm on tick over it seemed to be running ok, but as soon as I hit the gas pedal it wanted to die.
I think that the 2 venturis closest to the wing are the secondaries and only play a part when you press hard on the accelerator for overtaking.
The 2 nearest the wing are the primary barrels, in use for all of the rev band.
2 questions :- when you squeeze the accelerator can you see the accelerator jets squirting fuel into 2 of the barrels, I think the primaries?
And also was this the same problem before the carb rebuild, because if so isn\'t it possible that the problem\'s elsewhere?
Manual is out of the cupboard now but it\'s very complicated to try and follow the innards of the carb. I\'ll have a go though and get back ASAP.
Still don\'t think its fueling. Still think you want to check the ignitors.
http://www.rx7club.com/showthread.php?t=742083 - off car
http://www.rx7club.com/showthread.php?t=742084 - on car
Shaun
Thanks for your time David, but I\'m trying to find someone that knows carbs, and does not need a computer to tell him what to do.
At present there is no real change to the car with all the new bits added including the carb rebuild, when the engine is under load there is no real power.
Quote from: shaunwil;650406Still don\'t think its fueling. Still think you want to check the ignitors.Shaun (http://shaun)
it could have lost an ignitor and be running trailing only which is breaking up at revs but I still reckon its the accellerator pump and the secondaries.
We should have a sweep to guess the problem!
To be fair, it could be anything and trying to diagnose the problem without the car is very difficult.
I\'ve bee there myself with a rotary that wouldn\'t run properly.... frustrating ain\'t the word!
Does sound like what mine did when the igniter died. Bogged down horribly and refused to rev pat 5.5k. Knew it wasn\'t the petrol pump, was on gas :Giggle
Shaun
All the plugs are sparking.............Just been talking to a guy who seems to know what he is talking about but as you would imagine can not take a look at it untill sometime in December....................................frustrating it sure is............
Shaun when you say igniter do you mean the coils, as both of those are ok.
The symptoms you describe Dibs seem to drop across all of the Carburetor functions at the same time; by that I mean Idle is affected (hunting), mid band power is affected (can\'t get on the trailer), and high speed revs are affected (can\'t get over 5500 revs). Since these functions are carried out by different mechanisms within the carb I\'m really doubting that the problem will be in there.
A failed ignitor is a new idea certainly worth following but if we are on a sweep then Bags I vacuum pipes to dizzy vac retard and inlet gasket/manifold system...unless I can\'t have both of these together.
Quote from: A7RXY;650408Thanks for your time David, but I\'m trying to find someone that knows carbs, and does not need a computer to tell him what to do.
At present there is no real change to the car with all the new bits added including the carb rebuild, when the engine is under load there is no real power.
You\'re too far from Haywood in Berkshire I take it?
Idea...Why not put a general post up on the club..\'Want a 1st gen specialist near Essex\'. A good few engine rebuilding specialists are on here and the old timers should be able to help if you can get the car to them. Then there\'s some on the other site but they\'re perhaps further away still.
I have now been through the w/s manual and found the igniters, if they are not to expensive I will order new ones.........
Quote from: A7RXY;650438Shaun when you say igniter do you mean the coils, as both of those are ok.
I see you\'ve found them now in the manual.
They are simple plug in modules screwed to each side of the dizzy.
(http://i589.photobucket.com/albums/ss333/gsxrmovistar1/1.jpg)
(http://i589.photobucket.com/albums/ss333/gsxrmovistar1/2.jpg)
I seem to remember that they were quite pricey last time I bought some ( about 15 yrs ago)
There are plenty of people breaking running cars due to body rot at the moment. It may be worth getting a price fro some 2nd hand ones off a known runner if new prove too costly.
It\'s about a 2 minute job to swap them.
Quote from: A7RXY;650295Right this morning I tried Ians idear, running from a can striaght to the pump, no change, so no longer going to remove the tank.
I was running it this morning from both the tank and can and it was reving up to 6000 and then dying sometimes could catch it and keep it running other times it would conk out. Took the air filter off and two pots of the carb closest to the wing were full of fuel, and the other two were misting, thats when I felt I was getting in to deep so came on here....................help.......
Ps when it was running when warm on tick over it seemed to be running ok, but as soon as I hit the gas pedal it wanted to die.
When you say the secondaries are full of fuel do you mean its got pools of fuel in there because the only way that could happen is if the secondaries were staying shut, hence the symptoms. Standard secondaries are vacuum operated and if you rev the car while looking down the carb you should see them open, use a mirror in case you get a backfire. I have converted my secondaries to manual operation, very easy with a bit of wire around the linkage.
If you want to try igniters ive got some you can have and I also have a complete carb if you wanted swap over to test.
Thanks Ian, do you have photos at hand or did you take those for me, if so respect...............
just nipped out into the garage!
Quote from: myatt1972;650465When you say the secondaries are full of fuel do you mean its got pools of fuel in there because the only way that could happen is if the secondaries were staying shut, hence the symptoms. Standard secondaries are vacuum operated and if you rev the car while looking down the carb you should see them open, use a mirror in case you get a backfire. I have converted my secondaries to manual operation, very easy with a bit of wire around the linkage.
If you want to try igniters ive got some you can have and I also have a complete carb if you wanted swap over to test.
Are the secondaries the ones nearest to the wing if so they did have pools of petrol in them, they were dry when I took the air cleaner off, but after running the car and turning the igintion off I noticed they were say half full and there appeared to be petrol trickling in.
As for the igniters I will chk the price tomorrow, just a thought I have sparks at all the plugs, if one of the igniters was down would this still happen.....
Quote from: myatt1972;650465When you say the secondaries are full of fuel do you mean its got pools of fuel in there because the only way that could happen is if the secondaries were staying shut, hence the symptoms. Standard secondaries are vacuum operated and if you rev the car while looking down the carb you should see them open, use a mirror in case you get a backfire. I have converted my secondaries to manual operation, very easy with a bit of wire around the linkage.
If you want to try igniters ive got some you can have and I also have a complete carb if you wanted swap over to test.
That\'s a good point.
If you can do a temporary manual operation for your secondaries ( wire or zip tie the linkage as Keith says, so that the secondaries open with the primaries), you will then be certain that they are opening.
The engine may flat spot slightly but should rev up to the redline, no problem. ( unless theres another problem of course)
There are plenty of threads on how to do this on the net.
I\'d definitely try this before spending any more money on it.
Secondaries are nearist to the wing and if you have fuel trickling in without the engine running something is wrong. If you have good strong sparks at the plugs I would think the igniters are ok.
Keith..
I will try to wire the pimary and secs together tomorrow and report back.
Once again thanks to you all for your help.
Quote from: Ian65;650459I see you\'ve found them now in the manual.
They are simple plug in modules screwed to each side of the dizzy.
There are plenty of people breaking running cars due to body rot at the moment. It may be worth getting a price fro some 2nd hand ones off a known runner if new prove too costly.
It\'s about a 2 minute job to swap them.
Thats the ones ! I got a second hand one off pip a while ago. Wasn\'t too silly price either.
QuoteA failed ignitor is a new idea certainly worth following but if we are on a sweep then Bags I vacuum pipes to dizzy vac retard and inlet gasket/manifold system...unless I can\'t have both of these together
Forgot about that. Mine is setup in the secondary position because my throttle and carb don\'t have the vac pickup. Pip said he runs his race car that way but it uses a little more fuel. Possibly an easy thing to test if at fault.
Shaun
Shaun
Right hear we go. This morning I took off the air filter pan started the engine manually operating the secondarys and bingo it rev\'ed ok, then from the pedal it was reving around to 7500, maybe the sec\'ys were sticking, anyway engine now warm and ticking over at about 1000, not hunting, replaced air filter and still ticking over, sat in car pressed the gaz pedel and it died, thats where I\'m at the moment as it would not start again so now waiting for engine to cool and see what happens.
One thing I did notice when the air filter was off and manually operating the sec\'y was that there only appeared to be fuel comming out of the front secondary.
Keep you posted
Dibs
Good news, sounds like a breakthrough. Change my bet can I?
Just got it started again, does not want to start without choke, it will rev to just under 7000 then a surge takes it round to nearly 8000, but I have to feather the gaz pedal in, if I press it straight down it just dies. the car is on axle stands at pres so can not road test it.
Both secondaries opening now and reving round to 8000, still have to feather it in thou, just the flat spot at about 1200rpm, can\'t wait to road test it, hope to do that this weekwnd.
Good news!
are the secondaries opening via the vacuum signal or have you wired them to open manually?
If it\'s flat spotting, you may have a slight problem with the accellerator pump.
The function of the accelerator pump is to squirt extra fuel directly into the primaries when you accellerate. This has the effect of making the mixture richer and stops the engine from missing and spluttering.
If this accelerator pump isn’t working properly, when you put your foot on the gas, the engine will lean out as it seems to be doing.
Your secondaries should open via a vacuum signal.
If they stay shut, you lose your top end power. When you manually opened them, it revved up as we thought that it may do although it will still be lumpy if the acc. Pump isn’t working properly.
If the car has stood for a few years, you could have the passageways inside the carb gummed up with old fuel which will block out the vacuum signal to the secondaries and cause you untold grief.
You can leave the secondaries wired to the primaries if you want ( it\'s a performance mod that many owners do) but if you do you will find that it flat spots when the accellerator pump can\'t cope with the sudden demand for fuel caused by all 4 venturies opening together and you need to modify the accellerator pump to enable it to pump sufficeint fuel into the carb to give a smooth operation. If easy to do and there are loads of threads on the net about it.
The downside is that your fuel economy will suffer. The upside is that it will go like a bat out of hell!
You\'re getting there now though! Well done!
Just needs a bit of tweaking now.
Cheers,
Ian
Thanks Ian, I have not wired the two together, I chk\'d the web but could not find any info, I was on my own so I could not see if the sec opened from the pedal, but they sounded as if they did.
I will now read up on the accellerator pump, I will not be able to work on the car again untill Friday so will have a go then.
A bit of light reading on the acc. pump...
http://www.rx7club.com/showthread.php?s=&threadid=238028
Thanks Ian I have read through it a few times, still not sure where the acc pump is situated on the carb, when the carb was rebuilt the diaphragm should have been changed so hope either it just needs adjusting or at worst the checkballs are stuck, now all I need to do is locate the adjustment screw.
(http://i853.photobucket.com/albums/ab97/myatt1972/carb1.jpg?t=1256672989)
(http://i853.photobucket.com/albums/ab97/myatt1972/carb2.jpg?t=1256673053)
(http://i853.photobucket.com/albums/ab97/myatt1972/carb3.jpg?t=1256673250)
(http://i853.photobucket.com/albums/ab97/myatt1972/carb4.jpg?t=1256673278)
(http://i853.photobucket.com/albums/ab97/myatt1972/carb5.jpg?t=1256673314)
(http://i853.photobucket.com/albums/ab97/myatt1972/carb6.jpg?t=1256673356)
What can I say..................Thanks Keith
Update....Managed to get a couple of hours in today to chk the acc pump it was then I noticed that the acc pump rod was not connected, to conect this I had to take off the carb, two of those nuts are right B\'s to get to, conected it and refitted the carb, those nuts even harder to get back on, started the engine, yes it started, turned it off to chk the acc pump still not working, started again secondaries only work manually, the guy that rebuilt that carb for me must have been a builder cos he was no mechanic. So thats it so far...............Anybody know where I can get a good rebuilt carb from someone who knows what they are doing, as this carb has cost me £200 so far and its turned into a pile of junk.................
........P155ed off of Upminster....
Dibs,
don\'t let it get you down.
If it was me, I’d get hold of a carb and base plate off a running scrap car and just bolt it onto your engine. If it hasn’t been messed with, it should go straight on and the idle, emissions etc should be fine. I think Keith ( Myatt 1972) mentioned that he may be able to sort you one out.
The alternative is to stick with your carb and either become a Nikki carb expert yourself ( which you will do eventually!) or throw some more money at it and get someone else to set it up and maybe rebuild it again. They are a complex thing to get your head around and although you’ll get to the bottom of the problem eventually, who knows how long that will take.
The only way to rebuild a carb is to do it properly, full strip, clean, re-clean, rebuild and set up. If the bloke who did yours just took it apart and then put it back together with the parts from the rebuild kit, it won\'t be a reliable carb.
A good second hand carb is much the easiest and less stressful way to get your car back on the road. An easy bolt on fix and they are readily available. Just get one of a car that you know runs or has done recently. I wouldn\'t bother getting a rebuilt one because unless you can guarantee the quality of the rebuild, you may end up back where you are now.
A known second hand carb from a trustworthy source is the easiest and cheapest way back to RX7 heaven!!
Cheers Ian, I know you said the other day how frustrating it can get..........boy were you right.
Shout if you want a second hand carb, Ive got a couple spare.
I dont want anything for it just cover the postage.
Keith.
Keith, I will take you up on one of those, do you know if they came off a running car, as it would be nice just to bolt one on and get running again.
If you can email me on, d underscore i underscore ball at hotmail dot com, we can work out the details.
Thanks
Dibs
E-mail sent
Keith.
Thanks.............have replied
i had a simlier problem with mine after takinging it to santapod but mine was only running on the secondaries (nuffing down low was a very noisey trip back home having to keep it above 3500rpm got some strange looks at the lights and roundabouts) after taking off the carb myself and using the haynes manual cleaned it and put it back to geather and hay presto fixed although it was just the jets on mine that were blocked
Any joy with the carb ?
Sorry Keith, started a new job last week so working 7 days a week at pres, you know show willing............you cant do enough for a good boss.........and they told me I was the boss.
Right here we go..........fitted the carb today that Keith sent me, thanks Keith you are a top man, started the engine, bingo it started, only problem was it would not rev below 3300, but revved right the way round to 8000 and the buzzer without any hesitation, after running for a while trying to lower the revs, I noticed smoke comming from under the car, on inspection looking under the car I could see the centre section of the exhaust was glowing red hot. I assume from this that it was burning fuel in the exhaust, hence revving at 3300.
So here we go again, I will order a new carb rebuild kit to rebuild my original carb, unless someone knows an expert who can do it for me.