Eriks85Rx7

Take a look at these vids. Car stutters during reving smokes a lot of blue smoke usually it didn't for some reason today. What could be causing this stutter? Is this motor acting normal. Im not sure how smooth a carb'd turbo 12a is supposed to be.

http://www.youtube.com/watch?v=_ArqsFZm-Kk

vid 2
http://www.youtube.com/watch?v=21lqwbDDdEQ

Jobro

iTrader: (2)

I saw coolant on the outside of the motor at the end of the 2nd movie. It was pooled up near your plate that adapts the outlet from the turbo to the inlet ports. That would be from perished water o rings (cheap/relatively easy fix) between the rotor housings and your adapter plate. Or a blown outer coolant seal (extensive/time consuming fix).

Can you tell me about that intake plate? Out of interest how does it get air to the secondary ports?

I would hazard a guess that you can get that idle silky smooth with all the problems sorted


Does it stutter in gear when driving and revving? What vacuum does it idle at 800-1000 RPM at? What timing are you using? How well is the carburetor tuned?


Blue Smoke would indicate that the engine has either

#1 Worn Side Housings
#2 Worn Metal Oil Ring Cages
#3 Worn Rubber Oil Ring Seals
#4 Worn/Damaged Oil Seal in Turbocharger


Solutions to get rid of Blue Smoke if it persists in order of ease/price

Fresh Oil + Filter of right type (OEM Mazda filter and 20W-50)
Making Sure Crankcase vent system working
Rebuild/Check of turbocharger

Engine Rebuild

MOBEONER

iTrader: (18)

sounds like you are running out of fuel or maybe too much fuel for that matter....what size carb it that?

you also need to check that coolant issue.

brandon davis

iTrader: (3)

What is your fuel system setup?

Eriks85Rx7

Ok here is my set up

NEWLY Rebuilt 12A fully broken in excellent compression of 130 psi
Turbo is used with 25,000 miles on it. In the video you can notice the car did not blow blue smoke. It is parked on a incline... so if it burns while its level it means oil is getting somewhere it shouldn't..
Fuel is 2-4 psi stock replacement pump
Carb is a Rebuilt DHLA
Timing im not sure I have a timing light so I could probably make a video and show you but it is supposively right where it needs to be.
The coolant I know what it is from.. I forgot to weld up/ plug the stock ports on the motor where coolant flows into the stock manifold. Well this manifold has no ports for coolant. I didn't tighten the manifold enough I guess and the intake mani gasket got soaked and then shriveled thus causing it to leak.

I tightened it up a little and it helped for a while but it obviously still leaks.
Car does stutter in first gear and a little in second.
It clears up after it burns off the excess oil from idling but it only stutters in the lower rpms. Once it gets above 4 you can see if rev's nicely.




(PM with MDX)

Thank you I appreciate it. The whole ignition system is new. Everything except the distributor itself. It has power through all the gears. Except when you flat out floor it, it bogs at first the takes off and will rev to 7k fine in 1st and 2nd but in 3rd @ 4500 the power suddenly cuts off if you leave it stomped. But if I go to 4th and stomp on it the car will go way past 5k fine and pull hard... its very confusing.


thought this might help us all trouble shoot.

Jobro

iTrader: (2)

Firstly I would strongly suggest you do the following before you do anymore diagnostics!

Drain Coolant
Remove intake manifold
Replace Intake Manifold O ring with new item.
Clean intake manifold gaskit if its in good shape.
Apply Hylomar to o-ring, o-ring grove and the mating surface on the intake manifold
Apply Hylomar to the cleaned/new intake manifold gasket, the intake manifold mating surface, and the engine block where the gasket mates. Vacuum leaks/coolant into intake are something else you don't want in the mix. If you reuse the coolant that should barely cost you $15!


The running out of puff situation I have had before with a non turbo carby rotary. Now that sounds like a fuel flow problem to me. Back when I first bought my car it had a blocked fuel filter. It would run out of fuel at the middle of 3rd gear from a 1st gear start if you floored it.

I read you have a factory replacement fuel pump, so I assume you replaced the filter at the same time. If you check the filter and its fine I would be guessing that your fuel system is inadequate. A good start would be to get a higher volume rotary-type pump such as a carter gold, and a return style fuel pressure regulator. Another option is using the factory replacement pump as a lift pump, and pumping that fuel into a surge tank. That way you have a 1L buffer between your fuel pickup in your tank and your engine.

The stutter on throttle change could be something to do with the throttle pump inside the carby. It could also be something unfixable such as the problem that the *wet* area of your intake manifold is from the base of your carbys, through your turbocharger, and then your piping. Who knows how badly fuel would pool in there/impossible to remove lean spikes.


What happens if its warmed up, and you are cruising along in 2nd/3rd and you very slowly open the throttle from say 5/10% to 100%. Does it still stutter?

rotary84

iTrader: (4)

Fuel is 2-4 psi stock replacement pump - HHHMmmmmm i dont think thats enough for your turbo

Jobro

iTrader: (2)

Pressure wouldn't be the problem here, because its a draw through setup. The turbo looks like a vacuum source to the carby!

bumpstart

i suspect a few issues

check carb float/ needle/seat and the fuel pressure
- and carb install for lean or vibration
( dead head fuel regulator setups also creep and vapour lock )

and i suspect you have a lazy ignition module ( or two ) or a HT coil/ lead/ button that is sick , and intermittent with load and ambient conditions

PS
sometimes smoke issues are related to the sump breather system not being held under slight vacuum and failing to assist the turbo oil to drain away
( particularly in turbo cars )

check the filler neck breather layout for functional operation

680RWHP12A

your fuel pump is the reason its cutting out. you need more volume not more pressure. go with a malory 140 or a holley blue and yur issue will be resolved.

Eriks85Rx7

Im hesitant to think it has lack of fuel because most of the time while driving even at high rpm high speed it seems like the car is choking on fuel. When i let up off the gas the car seems to gain back its senses.

My filler neck just has an open whole on in the neck. No filter on the hole or tube. It is just an open hole. What should I do with that whole what purpose does that serve? I thought it was for emissions?

trochoid

iTrader: (6)

You need ti install 20 mm freeze plugs in the housing coolant ports. That will take care of the problem and allow you to remove the intake without draining down the coolant system.

Jobro

iTrader: (2)

Sure its 20mm? I think its 19mm. I have 20mm plugs are they are too big to get in without belting the FUDGE out of it.

trochoid

iTrader: (6)

Positive, part # is Dorman 555-101. I buy them by the box. Trick to installing them is to use a socket that fits inside the lip of the plug and a short extension to hold on to while tapping it in. Hole must be cleaned out first, I use a die grinder and sanding roll, then mix up some JB Weld to make sure it seals.

FBsliderseven

iTrader: (2)

mixture adjustment?
my supercharged seven sounded exactly like that found out it was running super rich (turned out the screws way too much) , but im not sure if it relates to a turbo.

bumpstart

by "backing off the gas " you are referring to backing down the accelerator pedal??
if you do this, and the engines seems to pick up out of its dead spot
then car IS LEANING DOWN

backing off the throttle is restricting the AIRFLOW so as to match the rate the petrol is being atomised
this is a sure indication that fuel flow volume rate/ pressure and your float levels are not up to it

- bigger fuel pump with feedback fuel reg system ( no dead head de-rate of flow )
and a good adjust of the float level is required

PS
it may be a blocked line filter in fuel supply that's made the issue rear

( and PS, prime your carb, and uses a couple of pumps before starting to crank it over )

PSS
yes, to be emission complaint
those fittings on the filler neck need to flow air under slight vacuum to inlet
( and assist the turbo oil to drain from turbo to sump )
its easiest to sort it with a filter and check valve for air supply on one nipple
and the other nipple heading full time to the air cleaner
-some will fit a catch or charcoal can in between
( so sump fumed air constantly flows to inlet filter under engine running, and a trap beween them to catch vapour when not )

FBsliderseven

iTrader: (2)

well if your gonna run a turbo you should upgrade your fuel pump. my fb streetported fb had fuel problems because the pump was not big enough. upgraded to a holley red and works great now.

Hyper4mance2k

iTrader: (40)

The stock fuel pump isn't enough for a stock ported 12a with a weber. It's not going to flow enough for it being turbo'd. 680RWHP builds carb'd turbo rotaries for a living, so i'd advise you to listen to him. Also, I have owned 2 blowthrough turbo FB's, so listen to me. You need a real fuel pump. Go with either a Holly blue/black or mallory 140 or bigger, a carter might even cut it if you're going on the cheap.

p.s. I'd like some high res pics of under your hood. I love turbo FB's!

myersprostatus

iTrader: (2)

you should really go with a new fuel pump. It helped my 7 out. got a denso supra pump. The blue smoke could be from your turbo, since it is used thats a very good hint it may in fact be the turbo. Just rebuild it. turbos arent hat expensive to rebuild. BNR turbo does it fairly cheap.

rotary84

iTrader: (4)

HE IS RUNNING STOCK FUEL PUMP MAN !!!!! That is not enough for his turbo

yetterben

Coming from another turbo owner get a better fuel pump. Oil issue could be tons of things but also check the drain line for the turbo.

Super82

iTrader: (1)

Wasn't this car just on eBay? I swear I just saw it on there.

Eriks85Rx7

yes this car was on ebay. I had lost hope but now I guess im going to work on it whenever i have extra cash/ time.

Just to clarify this car has ALL NEW parts except the alternator, new rad , all new fluids.

I had a 13b fuel pump on there and that was WAAAYY too much fuel! So don't think that I put a stock pump on for kicks.
I did talk to 680rwhp12a he called me. We talked and he was going to send me a pump but I put the car up for sale before he could send it so, (im assumming he did not send it for that reason) I bought a regulator to "regulate" the fuel flow from my 13b pump. A malpassi one at that and it could not regulate it below 7psi.. so that pumped way too much fuel! So i figured a 2-4 psi one would be plenty..

SCCAIT7

Whew - Lotz of info here - Where do you stand?

SCCAIT7

On second review - I am not sure fuel pressure would be an issue at the RPM's your playing with right now. The engine seems to hesitate all through the band. At this point I am not sure too much fuel pressure is the issue.

1.) Have you checked float levels?
2.) Did this car ever run with this setup?
3.) Those Webbers are insane to tune... Then you throw in a huge turbo!
4.) What happens if you put your foot on the floor ... will it pull through the hesitation or stall?