i know you guys are good

tweiss3 · 10-20-2010, 07:10 AM

Since i am pretty new to working on rotaries, and i cant always spot issues as easy as i can on my other car, i need some help. I read the fsm about a million times, but some of the diagrams suck.

The car: 91 (s5) non turbo
Only mods include new magnaflow direct fit cat system (single 3 way cat), corksport catback (2.5"), and cone filter replacing the airbox ( mini filter on the air pump intake tube). Premixing half to one. Completely stock otherwise, supposedly. I am replacing the O2 sensor today if i can pick one up from autozone.

The symptoms, related or not:
The car sometimes has issues staring cold. It will almost start immediately, then not and i have to flood start it which it tuen starts immediately. Oil doesnt smell like fuel or seem to be breaking down (doing uoa this saturday when i change it).

When the motor is warmed up, and i just start driving even with a sligjter heavy foot, and i come to a stop, i smell fuel. It goes away after about a good 15 minutes of driving in rull warmup.

What i have seen that may be odd:
The charcoal canister, has the two upper tubes that go to the fuel lines/evap system, but there is one coming out the bottom going to nothing?

This pictire is right below the throttle body:

Should those two capped nipples be going to something? Should i replace the caps? They appear warn and cracked.

Your guys help is appreciated.

project86 · 10-20-2010, 07:37 AM

Rotaries=very cold blooded=your harsh cold start.. they run rich.. especially in the cold, which is probably why youre smelling gas.. i was worried about the same thing with mine when i first got it.

RETed · 10-20-2010, 06:06 PM

That "valve" right in the middle of the pic that has the bigger nipple that's capped is the sub-zero assist valve.
Mazda has instructions to "delete" those damn things.
So don't worry about that...

I dunno what the smaller one on the left is for.

-Ted

project86 · 10-20-2010, 06:12 PM

Quote:

Originally Posted by RETed

That "valve" right in the middle of the pic that has the bigger nipple that's capped is the sub-zero assist valve.
Mazda has instructions to "delete" those damn things.
So don't worry about that...

I dunno what the smaller one on the left is for.

-Ted

is that the same thing as the cold start deal/wax pellet deal?

tweiss3 · 10-20-2010, 06:52 PM

yes. I also forgot to mention, i get a wierd idle at times, it goes up and down from 900 to 1400, is this normal.

project86 · 10-20-2010, 06:57 PM

i know mine was kinda erratic for a while... now im trying to remember why.. some of it was due to vacuum leaks but i thought there was something else that was causing it too.

tweiss3 · 10-20-2010, 07:03 PM

I wonder if those caps rotted out and cracked are causing it, but every other vac line looked and felt prestine.

project86 · 10-20-2010, 07:10 PM

if those caps are bad that could cause some.. man.. i wish i could remember if there was something else.....

RETed · 10-21-2010, 04:52 AM

Quote:

Originally Posted by project86

is that the same thing as the cold start deal/wax pellet deal?

No.

-Ted

project86 · 10-21-2010, 07:54 AM

^^Thank you

NoDOHC · 10-21-2010, 09:56 PM

The idle is slowly revving to 1400 rpm, then dropping quickly to 600-700, right?

This indicates that the TPS is not adjusted correctly. The ECU thinks that the engine is at 0 throttle, and it isn't (thermal wax). This results in it revving until it hits the decel fuel cut, resulting in rrrrrrrrrrrrr -- duh rrrrrrrrrrr -- duh, etc.

tweiss3 · 10-21-2010, 10:13 PM

Yea, it does exactly that, but not all the time. So what do I do to fix it? Im broke after the new Oil pressure switch, O2 sensor, fuel filter and oil change. Man do bill suck.

project86 · 10-22-2010, 07:55 PM

you can get a TPS tool that will plug into the diagnostic port and you can adjust it that way.. its cheap so if it doesnt work you wont be out much at all.

tweiss3 · 10-25-2010, 11:49 AM

So, saturday, i replaced my oil pressure switch so my gauge would work again (unfortujately didnt work) but i found my fuel smell source. The canister runs a soft line to hardline to softline to the drivers side, and is left un attached to the motor. My fsm shows it to jeed to be attached to the oil filler tube, is that correct? I have only one nipple on the filler tube instead of two shown on the fsm. If it doesnt attach there, where does it attach, i couldnt chase it down.

10-20-2010, 07:10 AM	#1
tweiss3 Mazda Lover Join Date: Aug 2010 Location: Akron, Ohio Posts: 319 Rep Power: 16	i know you guys are good Since i am pretty new to working on rotaries, and i cant always spot issues as easy as i can on my other car, i need some help. I read the fsm about a million times, but some of the diagrams suck. The car: 91 (s5) non turbo Only mods include new magnaflow direct fit cat system (single 3 way cat), corksport catback (2.5"), and cone filter replacing the airbox ( mini filter on the air pump intake tube). Premixing half to one. Completely stock otherwise, supposedly. I am replacing the O2 sensor today if i can pick one up from autozone. The symptoms, related or not: The car sometimes has issues staring cold. It will almost start immediately, then not and i have to flood start it which it tuen starts immediately. Oil doesnt smell like fuel or seem to be breaking down (doing uoa this saturday when i change it). When the motor is warmed up, and i just start driving even with a sligjter heavy foot, and i come to a stop, i smell fuel. It goes away after about a good 15 minutes of driving in rull warmup. What i have seen that may be odd: The charcoal canister, has the two upper tubes that go to the fuel lines/evap system, but there is one coming out the bottom going to nothing? This pictire is right below the throttle body: Should those two capped nipples be going to something? Should i replace the caps? They appear warn and cracked. Your guys help is appreciated. __________________ 2004 Mazda6 V6 5-spd - still waiting on money for a motor 1991 Mazda RX7 NA 5-spd - my new DD with 145,000 miles

10-20-2010, 07:37 AM	#2
project86 Can't.Make.Up.My.Mind. Join Date: May 2009 Location: Murfreesboro, TN Posts: 1,377 Rep Power: 18	Rotaries=very cold blooded=your harsh cold start.. they run rich.. especially in the cold, which is probably why youre smelling gas.. i was worried about the same thing with mine when i first got it. __________________ '90 GTUs Stay up to date with my photography '06 Toyota Highlander Hybrid '10 Toyota Prius "Initial Success or Total Failure"

10-20-2010, 06:52 PM	#5
tweiss3 Mazda Lover Join Date: Aug 2010 Location: Akron, Ohio Posts: 319 Rep Power: 16	yes. I also forgot to mention, i get a wierd idle at times, it goes up and down from 900 to 1400, is this normal. __________________ 2004 Mazda6 V6 5-spd - still waiting on money for a motor 1991 Mazda RX7 NA 5-spd - my new DD with 145,000 miles

10-20-2010, 06:57 PM	#6
project86 Can't.Make.Up.My.Mind. Join Date: May 2009 Location: Murfreesboro, TN Posts: 1,377 Rep Power: 18	i know mine was kinda erratic for a while... now im trying to remember why.. some of it was due to vacuum leaks but i thought there was something else that was causing it too. __________________ '90 GTUs Stay up to date with my photography '06 Toyota Highlander Hybrid '10 Toyota Prius "Initial Success or Total Failure"

10-20-2010, 07:03 PM	#7
tweiss3 Mazda Lover Join Date: Aug 2010 Location: Akron, Ohio Posts: 319 Rep Power: 16	I wonder if those caps rotted out and cracked are causing it, but every other vac line looked and felt prestine. __________________ 2004 Mazda6 V6 5-spd - still waiting on money for a motor 1991 Mazda RX7 NA 5-spd - my new DD with 145,000 miles

10-20-2010, 07:10 PM	#8
project86 Can't.Make.Up.My.Mind. Join Date: May 2009 Location: Murfreesboro, TN Posts: 1,377 Rep Power: 18	if those caps are bad that could cause some.. man.. i wish i could remember if there was something else..... __________________ '90 GTUs Stay up to date with my photography '06 Toyota Highlander Hybrid '10 Toyota Prius "Initial Success or Total Failure"

10-21-2010, 07:54 AM	#10
project86 Can't.Make.Up.My.Mind. Join Date: May 2009 Location: Murfreesboro, TN Posts: 1,377 Rep Power: 18	^^Thank you __________________ '90 GTUs Stay up to date with my photography '06 Toyota Highlander Hybrid '10 Toyota Prius "Initial Success or Total Failure"

10-21-2010, 09:56 PM	#11
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 18	The idle is slowly revving to 1400 rpm, then dropping quickly to 600-700, right? This indicates that the TPS is not adjusted correctly. The ECU thinks that the engine is at 0 throttle, and it isn't (thermal wax). This results in it revving until it hits the decel fuel cut, resulting in rrrrrrrrrrrrr -- duh rrrrrrrrrrr -- duh, etc. __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)

10-21-2010, 10:13 PM	#12
tweiss3 Mazda Lover Join Date: Aug 2010 Location: Akron, Ohio Posts: 319 Rep Power: 16	Yea, it does exactly that, but not all the time. So what do I do to fix it? Im broke after the new Oil pressure switch, O2 sensor, fuel filter and oil change. Man do bill suck. __________________ 2004 Mazda6 V6 5-spd - still waiting on money for a motor 1991 Mazda RX7 NA 5-spd - my new DD with 145,000 miles

10-22-2010, 07:55 PM	#13
project86 Can't.Make.Up.My.Mind. Join Date: May 2009 Location: Murfreesboro, TN Posts: 1,377 Rep Power: 18	you can get a TPS tool that will plug into the diagnostic port and you can adjust it that way.. its cheap so if it doesnt work you wont be out much at all. __________________ '90 GTUs Stay up to date with my photography '06 Toyota Highlander Hybrid '10 Toyota Prius "Initial Success or Total Failure"

10-25-2010, 11:49 AM	#14
tweiss3 Mazda Lover Join Date: Aug 2010 Location: Akron, Ohio Posts: 319 Rep Power: 16	So, saturday, i replaced my oil pressure switch so my gauge would work again (unfortujately didnt work) but i found my fuel smell source. The canister runs a soft line to hardline to softline to the drivers side, and is left un attached to the motor. My fsm shows it to jeed to be attached to the oil filler tube, is that correct? I have only one nipple on the filler tube instead of two shown on the fsm. If it doesnt attach there, where does it attach, i couldnt chase it down. __________________ 2004 Mazda6 V6 5-spd - still waiting on money for a motor 1991 Mazda RX7 NA 5-spd - my new DD with 145,000 miles