Rotary not rotaring!

[noresull]

Ok guys, here's the deal. I am the pit crew for Benracin. We have yet to get the car on a track for SCCA events, and plan to do so Next weekend at Blackhawk farms.

Anyways, We cannot get the darn thing to start. It is a 12A, with the stock carb, modified by Pettit, atleast that's what all the paperwork says http://Forums.ImprovedTouring.com/it/smile.gif. We have checked for spark at all four wires, all are sparking.

Last year, We were able to get it running, but not idle, and it would really run bad until the RPM's got up there.

My question(s) what are some of the common things to look for, what is the proper base setting for the idle mixture screw...So on and so forth.

I am a Ford Mechanic by trade, but I do not have alot of experience with carbureted vehicles, only Fuel Injection so go ahead and get technical, call me names, anything, I just want to see if You all know of anything in particular to look for/change/replace/beat with a hammer.

Thanks everyone in advance!

[Speed Raycer]

Others will know much more than I but start with the basics. Have you tried starting it with starting fluid? Rotaries with low compression are a bear to start, but we've always had good luck with Starting fluid.

Test your spark again and make sure it's wired correctly. Leading plugs on bottom, #1 is front rotor, Leading coil is the REAR one. If all this is right, check your timing in case someone's pulled the dizzy.

If the electronics check out, start on fuel (but be sure not to flood it). Is the fuel pump working? You should hear a sound coming from it in a stripped interior. If its ok, pull the line and make sure its pumping to the carb (bad regulator?), then reattach and check the float levels. There's a clear "window" on the front and back of the carb that the fuel level should be in the middle of.

This should get you started...

------------------
Scott
It's not what you build...
it's how you build it
http://home.swbell.net/srhea66/AllThreeProjectsRealSmall.jpg (http://www.angelfire.com/mo2/radrodder)
http://home.swbell.net/srhea66/PFMSigPic.jpg (http://www.pfmracing.com) http://home.swbell.net/srhea66/replica2small.jpg
E-mail me for deals on
Lightweight Replica Blocks!

[ddewhurst]

Ben & crew, the folowing information is copied from http://members.ij.net/mrmazda/

Read it all before you do anything. http://Forums.ImprovedTouring.com/it/smile.gif

Why won't my rotary engine start? What can I do to start it? 2002/09/27

A typical story goes something like the following:

It started just fine when I moved it out of the garage to wash it. Ever since I finished washing it, it just refuses to fire. I didn't get any water on the engine.
This isn't good for any engine, but you found the rotary engine achilles heel. You are playing Russian Roulette by starting a cold rotary Mazda engine and not allowing it to warm up completely before turning it off. If you do this often enough, eventually it will happen. It might even carbon lock. Just don't do it. If you must start it cold without letting it warm up completely, let it run at least two minutes. The longer the better.

One: If this happens to you and yours isn't an automatic, one solution is to push start the car.

Caution - Do NOT attempt to pull start your car. Upon starting, your car may lurch. This can quickly eliminate the space between the vehicles, or cause your car to run over the tow cable, damaging either or both vehicles.
Pushing spins the engine faster than the starter can. As long as you haven't done something else to prevent starting, this works quickly and rather easily. A hill also works well if available. When using either of these methods, do not use first gear. Let out the clutch after reaching a speed of at least 10 MPH, preferably more. Reverse will work if the downslope is facing the wrong way, but beware of the considerable additional danger. Using reverse on a hill should be your last resort.

Two: If yours is '88.5 or newer, simply holding your foot all the way to the floor while cranking may get it started. Cranking this way is supposed to disable the fuel injection and may get you on your way.

If yours is a GSL-SE, keep you foot entirely off the go-pedal, and try a burst of repeated extremely short start attempts, extremely short meaning roughly two seconds or less, followed by a pause of 4-5 seconds in between, and burst meaning 4-10 tries before a longer pause of up to one minute if it does not start. This procedure is ideally suited also to hot restarts when the engine balks instead of starting instantly.

Three: If you have time, simply waiting until later to try can sometimes do the trick. Sometimes several minutes is more than enough. Sometimes a few hours, overnight, or a couple days may be required. Often, no amount of waiting will help.

Four: Lacking time to wait, purging the engine of excess fuel is the next thing to do. With a fuel injected model, you can generally accomplish this by disabling the fuel pump and ignition, easily done by pulling the "engine" fuse or disconnecting the tach lead from the trailing coil, and cranking the engine 20-30 seconds. This process is more effective if you remove the spark plugs first. If you are due for new spark plugs, now is the time to change them. If reusing the old ones, dry them of any excess fuel or oil before reinstalling. If you want to preserve engine compartment cleanliness, stuff some rags in the vicinity of the plug holes to catch the excess fuel. This also serves as a safety function, reducing the possibility of an unwanted fire should an errant spark find the surplus fuel. With a carbureted car, disabling the fuel pump doesn't shut off the fuel supply, so the spark plugs must be removed to purge excess fuel. You can prevent the carb from receiving fuel by either disbling the fuel pump, or, because carbs use a low pressure fuel supply, pinching the fuel line to the carb with vice grips. Flooding is quite uncommon with carbureted engines, and skipping to method Four is generally easier and prudent when they have a hard start problem.

Five: If pushing isn't an option, and Two through Four above didn't work either, getting additional lubricant into the combustion chambers is required. First, make sure the battery is fully charged and the battery terminals are clean. Full cranking power is crucial in this circumstance. If your rotary is carbureted, just pour a small amount, a half ounce or less, of light oil or ATF down each carb throat. Because ATF is lighter viscosity than crankcase oil, it takes less time for the smoke to clear after you start it. If yours is fuel injected, the task is more difficult. Usually, removing the air duct from the throttle body and squirting the oil past the throttle blades is the easiest. You can inject the oil through the spark plug holes, but if you try to use the trailing (upper) plug holes, you have to get the oil to go through the 3mm hole that the spark normally sneaks through, so even though the leading plugs are lower down, they are easier to get oil through. On some models, there are unused intake manifold vacuum ports to which you can easily connect your oil pumper with a short piece of hose.



------------------
Have Fun ;)
David Dewhurst
CenDiv Milwaukee Region
Spec-7 #14

[noresull]

wow, nice post ddewhurst!

Anyways, We have tried starting fluid, it will run for about 5 seconds and no matter what is doen with the throttle linkage, it dies. We have noticed the fuel pump will fill the inspection windows on both of the float sight glasses, so I think that is part of the problem, however, if the car is started with starting fluid, no fuel pump, float inspection windows about full or close to the top, the car should stay running until the float chambers get close to empty, correct?

The car will run with starting fluid, which I assume is not good to use alot as it is not with regular engines, but I may be wrong.

Is the Rotary just that cold blooded that with no choke, it won't run in cooler weather?

I have heard of the Dreaded "Flood of Death", is this what we are experiencing? It seems to me like it isn't flooded though. We even replaced the plugs with the same results.

I am baffled. If it is truly just flooded, I guess I would like to know the best way to prevent this from happening.

P.S. We don't have a fuel pressure regulator, if We get one, what Should we set the pressure to?

[moto62]

So! You're getting spark and you're getting gas. Check the float level in the carb. Fuel S/B in the middle of the sight glass or maybe a little higher. Next, put in some fresh plugs. Check to make sure the the timing is correct.Find the TDC mark on the crank pulley and line it up with the pointer, and when you do, the ign rotor s/b almost parallel to the the engine block, front to back. Fire that baby up. If that doesn't work, then you need to get down and dirty. Assuming the engine is good, try a different carb.


------------------
Ray Lee Chee
[email protected]
Stamford,Ct

[joeg]

I must have helped rebuild at least a dozen rotaries and have seen numerous no-start scenarios.

The strangest was a "plugged" muffler (The Supertrapp end plates got completely coked-up from the prior mosquito-eater motor).

Make certain you eliminate that issue (and ignition timing) before swapping carbs.

BTW, the usual routine after rebuilds was to drag the car around the block for miles before it would roar to life. Quite thrilling, foolish and tempting the intervention of law enforcement!

Good luck.

Cheers

[ddewhurst]

Ben & Crew, I am not an expert on rotarys but I will try to help.

***P.S. We don't have a fuel pressure regulator, if We get one, what Should we set the pressure to?***

What fuel pump do you have & what pressure is it capable of pumping & is it pumping? As Scott mentioned, take the fuel line off at the carb & see if fuel flows. Get a fuel pressure gauge that will alllow you to read 2 to 5 psi & install it in the incomming line from the tank to the carb within the rubber line between the firewall & the carb.
You realy need a fuel pressure regulator & a fine reading gauge that has a very accurate tolerance on the gauge repeatablity. You need this info from the carb builder or previous owner. By myself not knowing your motor or carb I do not have a clue what the carb builder had in mind for fuel pressure. In Spec-7 by the rules we can not modify our carbs from stock so I may run a totaly different fuel pressure than your carb builder would suggest. I use the Holly red pump, a Holly regulator 1 to 4 psi & a 0 to 5 psi gauge. If I remember correctly, using the stock Mazda carb & fuel pump the pressure is approx 3.5 psi at idle (the pump is constant psi) & as the rpms are raised, more fuel is used so that the carb sees less presure. That's a whole different story.

Were these test starts with fluid within the last couple days ?

Has this motor ever ran continuously for you guys ?

If it has run continuously have you changed anything ?

***Anyways, We have tried starting fluid, it will run for about 5 seconds and no matter what is doen with the throttle linkage, it dies.***

With the air cleaner off after one of these test starts with fluid or during one of the tests starts with fluid while the motor is running look down the carb while by hand working the carb linkage is fuel squirting into the carb throat ?

***We have noticed the fuel pump will fill the inspection windows on both of the float sight glasses, so I think that is part of the problem, however, if the car is started with starting fluid, no fuel pump, float inspection windows about full or close to the top, the car should stay running until the float chambers get close to empty, correct?***

If I remember correctly the fule level will stay constant level in the windows at idle.

***The car will run with starting fluid, which I assume is not good to use alot as it is not with regular engines, but I may be wrong.***

Not a clue with this.

***Is the Rotary just that cold blooded that with no choke, it won't run in cooler weather?***

Yes the rotary is cold blooded. Per above if you are geting fule through the carb into the carb throat try using your hand as a choke. Also under cold conditions if you are using high flying racing plugs or modified plugs they can make life miserable. Use some cheap plugs untill you get this deal figured out.

***I have heard of the Dreaded "Flood of Death", is this what we are experiencing? It seems to me like it isn't flooded though. We even replaced the plugs with the same results.***

You could take a normal compression gauge with the psi holding device disabled & check the compression through the leading plug holes. View the gauge while the motor is rotating. You will see three readings for each time the rotar turns one revolution. One reading for each compression side of the rotor. With this poor mans pressure gauge you will get different readings than with a $1,200.00 Mazda gauge. I can not remember what the psi should be except that all three reading from one rotar revolution should be within approx 15 psi of eachother. With the poor mans gauge you will read less than the Mazda spec.

***I am baffled. If it is truly just flooded, I guess I would like to know the best way to prevent this from happening.***

For a starter get the fuel pump, filter, regulator, gauge & psi recomendations from the carb builder or someone who knows & uses a same carb. In the meantime put the stock carb on & maybe life will be better.

I am asking myself long distance, if the sucker starts with fluid & runs untill the fluid is gone (even tho the fluid is hotter than gas) IF IT IS GETTING GAS it seems as tho it should run.

If your at the Farm I'll see ya then. I am not racing, just viewing on Sunday.

David





[This message has been edited by ddewhurst (edited April 18, 2003).]

[GS10GA]

Well, it sounds like everyone has a good bead on whats what, but I saw no mention of changing the gas. Bad gas will screw you everytime, it may have run the car once before, even only two weeks ago but now it's not worth putting into the lawn mower. Drain and change your gas, make sure to drain the lines and carb also. Oh and if you have an inline filter make sure its installed correctly, we have a guy who has great intentions but no skills and he installed ours backwards.....hard start.....and didn't keep running.

Good luck and I hope I helped some!

------------------
To race, or not to race? Is that really a question?

[benracin]

Hey John, hope you don't mind if I add my 2 cents as monkey behind the wheel, but what I noticed about the engine is that when it is running, and that means off the starting fluid or even last year, it sounds to me like it's only running off one rotor. Kind of a lower sound, not as loud. When I would put the pedal down, probably around 50% down the other rotor would catch on and then it would be running fine. It didn't seem to be so related to high rpm but acceleration. Putting through the pits or coasting would cause it to run poor, like on one rotor. When I was on the track there didn't seem to be any problem at all because I was either accelerating or slowing down. When we were firing it up last night it had that same sound of just one rotor. It also wouldn't idle last year but I'm pretty sure that's due to it not firing on both rotors. To keep it running I had to blip the gas constantly. Sounds cool, but I'm sure it gets annoying after a minute.

I'll add a little history of the car, just in case it helps. I bought the car a year ago from a guy who raced it before. Looking at his log book it looks like he didn't race it much the last years he had it. I think the last entry into the log book was in 98. The car has probably done a lot of sitting.

The fuel has also been sitting in the car through the winter in a cold garage so I'm guessing it's gone bad. Talking about the issue here to my work buds who all drive motorcycles they all seem to think it's a gummed up float. Common prob in bikes that have been sitting all winter.

So there's everything I know, and now I need a nap. I'll shut up as wheel monkey and return this bad boy to John "Head Wrench" super man, super stud, guy that I owe my first child (if he'll take it) and probably a lot of beer.

And in my best William Wallace voice, "This car will be at Blawkhawk"!!! Oh, and running too.

[noresull]

Ok, let me try and answer every question and give You some ore info http://Forums.ImprovedTouring.com/it/smile.gif

The car was sitting all winter like Ben said, so the gas is getting replaced tonight. It is the stock 4 barrell Nikki carb, and was supposedly built by Pettit. I think what I may try doing is talking our buddy Ben into getting the carb sent to someone to give a=it a thourough going through or by a known good carb from a re-builder and start from there. We are running an inline fuel pump, Purolator brand. The pump is running for sure. It says it pumps 0-10 PSI, so We definitaly need a regulator, however, the car had the exact pump in it when the car was bought, We know this because that pump died shortly after the car was purchased.

Anyways Ben, get the credit card out and buy atleas the gauge and regulator like ddewhurst has and We will try and just shoot for what the service manual says for pressure.

P.S. Can someone give us a name and number of a good carb guy so We can call for prices and such?

[benracin]

Is it bad when you're on the chat room so much that people know to contact you through it? http://Forums.ImprovedTouring.com/it/smile.gif

[noresull]

Originally posted by benracin:
Is it bad when you're on the chat room so much that people know to contact you through it? http://Forums.ImprovedTouring.com/it/smile.gif


Shouldn't you be working? http://Forums.ImprovedTouring.com/it/smile.gif

[BrianB]

Look for a vacumn leak in the intake system( or anywhere else air might be sucked into the rotor housings). The engine may be sucking air but not through the carb.
A vacumn leak would explain no idle, running bad until it reaches an rpm that draws alot more air/fuel than the leak
Good luck,
BB

[Quickshoe]

Once you get the fuel delivery problem fixed I would suggest you look for huge vacuum leaks.

I once had installed an intake/carb and I couldn't get the idle low enough. While futzing with the carb linkage, thinking for sure it was hung up on something, I noticed that one header tube was starting to turn orange http://Forums.ImprovedTouring.com/it/eek.gif (in fairly good light!) Turned out to be a rather large tube on the intake manifold, back by the firewall IIRC.

As to the starting fluid routine. I'd be concerned about too many 5 seconds starts without oil injection. Speaking of oil injection, if the prior owners pre-mixed the fuel with a CASTOR based oil (gotta love that smell) it surely has separated in the tank.

[lateapex911]

First, relax, we've all been there, you'll get it soon!

OK, I would concentrate on the fuel issues. If you are worried about flooding, and lack of oil, put 4 old spark plugs in, and drop a little ATF in the engine while the throttle is half open and the starter is turning it over. Be sure to plug all vacuum hoses! Once you've done that, pull the plugs, put some rags near the openings, and turn it over to blow out all the crap.

Now, how do your float bowls look inside?? If you don't know, it's time to open them up. Likely there has been some water that has gotten pumped in there. It makes quite the mess. Mop it all out, and you might have to clean the jets. Do this with the carb off the car. You might need an extra top (air horn) gasket as it might tear when you pull the top off. Buy a carb rebuild kit ahead of time if you are doing this when the local Napa is closed. Actually they probably will need to order one! And they're not free! Be careful with the screws as they are soft. Spray carb cleaner thru the passages, and chack the operation of the accelerator pump. You need that baby working! Once everything is clean, put it back in.

Now, ditch the fuel filter. Then pull the inlet off the pump and put a fresh hose leading to a can of NEW gas. (This is only temporary!) Now, take the hose that feeds your carb, and point it to a container, and start your fuel pump. (The usual safety concerns about smoking, sparks and open fuel apply here!) Pump enough to flush the lines. Now, if you are getting fresh fuel, reattach it to your carb.

Set the idle a bit high, put fresh plugs in, and get ready, rotaries are VERY cold blooded without a choke, and require lots of cajoling when cold. The accelerator pump is your tool. It should start but it will run poorly on the idle circuit until it has a bit of heat. Use the accelerator pump to keep it going.

If this does the trick, be very suspicious of your tank. They are at the age when thay are rusty, and full of gunk. Very hard to clean. In a racing environment, you WILL find all the crap!

(Oh- the leftover ATF will kill a ton of mosquitos, make you think the motor is shot, smoke forever, and piss of all the neighbors for a half mile. Alll perfectly normal!)

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[noresull]

Ok, Well tonight We took the air horn off the carb, replaced the needles and seats, replaced the gaskets, flushed all the old fuel out of the tank, cleaned the carb, restored everything, pumped gas twice, She fired! Only ran for about 3 seconds, but Long enough to deduct We need a fuel pressure regulator, so We are going to get one and a gauge also. Tomorrow, I think We are going to try and get it running to warm it up and see what happens.

We have new plugs, and I think everything else is ok. I just need to get it warmed up and check the timing and I think everything will be good.

Thanks guys! Hopefully We get to meet everyone at Blackhawk Farms!

[Speed Raycer]

Congrats! Make sure you get the Holley FP reg. and not a purolator one. JUNK! I wouldn't waist you $$$ on a F/P guage that goes up to 15psi... not very accurate since you'll only be using a third of the guage. The generic setting for rotaries is 2ish psi. I found a guage from a science overstock website that was great and cost under $10.

Go to www.mazspeed.com (http://www.mazspeed.com) and search their archives for pressure guage. Theres a link to the site.

------------------
Scott
It's not what you build...
it's how you build it
http://home.swbell.net/srhea66/AllThreeProjectsRealSmall.jpg (http://www.angelfire.com/mo2/radrodder)
http://home.swbell.net/srhea66/PFMSigPic.jpg (http://www.pfmracing.com) http://home.swbell.net/srhea66/replica2small.jpg
E-mail me for deals on
Lightweight Replica Blocks!

[lateapex911]

You might also want to go to Paul Yaws site to get his angle on the parts you're looking at. I think it's
http://personal.riverusers.com/~yawpower/

Be prepared, he's brilliant and opinionated!

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[This message has been edited by lateapex911 (edited April 19, 2003).]

[benracin]

Well we started it up today, and not only did it fire right up, but it eventually settled down to an idle about 2 grand, and then, in a first for the race team, WE PASSED TECH! Yippie!

So thanks for the help folks. If I didn't start reading this site a year ago I would not only be lost, but I wouldn't even have a car!

And like John said, we'll see yall (if you're going I guess) at Blawkhawk. Thanks.

[planet6racing]

Ben (and crew):

Congratulations! Be sure to look me up when you get there. I'll be in the dark blue with yellow numbers Saturn (#92).



------------------

Bill
92 Saturn SL2 (SCCA ITA)
93 Saturn SL2 (Daily driver/backup car)
Planet 6 Racing
[email protected]

[noresull]

As Ben said, it Runs! http://Forums.ImprovedTouring.com/it/smile.gif

Remember when I said I don't have alot of experince with carbs? Well, here goes my inexperience. Do Fuel pressure regulators in carbureted vehicles require a return hose to bleed off the excessive pressure the regulator isn't letting past?

This regulator (http://store.summitracing.com/default.asp?target=search.asp&type=bysummitpart&searchtype=both&part=HLY-12-804) says it has three ports, is the third used for a return or is it for another purpose, i.e. a pressure gauge?

And to repeat what Ben said again, Thanks Everyone for the advice!

We will look everyone up at the farm!

[ddewhurst]

Ben & Crew, hay Crew do you have a real name ?

The three ports on the Holly 12-804 regulator your talking about has 1 incomming port & 2 outgoing ports. Incomming is from fuel pump. 1 outgoing will go to the carb & the second can be either pluged, or you can plumb your gauge, or you could plumb your gauge & your fuel sample hose.

I use the stock carb & there is a stock return line comming off the carb which returns fuel to the tank via a second line to the tank.

Do you guys have a Mazda workshop manal ? The raeson I ask is that number one you SHALL have one at all SCCA races. Part of the rules. Second if you had a manual there is a bunch that can be learned. Example you have a after the fact worked on carb & who knows what has been modified, may be they closed the return line haole. If ya had the manual maybe it would help with some of these thing.

Have Fun http://Forums.ImprovedTouring.com/it/wink.gif
David

[noresull]

My name is John. http://Forums.ImprovedTouring.com/it/smile.gif

The carb seems to have a line that has been sealed, however, there is a hose running from the front bowl to the catch tank. We have a service manual.

The carb is stock, atleast, We think so, it looks like all the pictures in the manual. http://Forums.ImprovedTouring.com/it/smile.gif

Anyways, thanks for the heads up on the regulator!