I have a 05 Mazda rx-8 with a Zex wet nitrous kit installed on it..65h.p. jets. Last Friday as i was on my way to the track,it backfired at low rpm's and i see from some threads and members that's a common problem when using nitrous. So as its no surprise i blew my UIM to pieces!

I grabbed another one laying around at pfsupercars,put it on,and now my car Still wont start. I changed my maf and the car just cranks but changes pitch so i know it is receiving fuel and has compression..

PLEASE HELP!!!!! Has anyone experienced this using nitrous?

 

I have done this a few times. Why your car will not start is a unknown. I always changed the UIM and a throttle body once, that bent the butterfly.
You might want to make sure the Throttle body is functioning correctly.
Did any plastic fall into the intake manifold?
I would pull the spark plugs and see if they're fouled/flooded.

 

I dont think any plastic fell into the manifold...i am going to take the plugs out and check if they are fouled,and also test and see if everything is firing properly. The car cranks and sounds like it wants to start,but doesnt turn over. Have u ever had this problem? And is your ignition system upgraded or are u still on stock parts?

 

Check to make sure all the vacuum lines are attached and all electrical is connected on the Oil Fill/Vacuum box under the UIM. I blew one of those up too.
I had the BHR Ignition Kit on when I blew mine up.

 

I backfired once also with nitrous, luckily I didn't blow my UIM... however my MAF did fly out of the intake and I blew both screens and the air filter. But my car started right back up after temporarily duct taping the MAF sensor back in place. Check the MAF and TB wiring, and hope you didn't get any shreds of debris down the intake manifold. Also verify that the butterfly valve opens and closes with the appropriate resistance.

 

cool thanks guys i will check all of these things and post later!

 

So i took the UIM off again,just to make sure everything was hooked up properly and i find a piece of the old UIM in the LIM...i removed that,checked everything else to make sure they were in order,and tried to start it but still wont start. I guess the only thing left to check would be the spark plugs?

 

What exactly are you guys all doing to cause a Nitrous backfire?

I'm running a 65 shot and knock on wood

/startwoodknock
/endwoodknock

This has not happened to me nor do I want to EXPERIENCE IT!!!!!!

 

so would fouled plugs cause the rx-8 to not start?

 

you mean like if it was flooded? yeah! you have had a nitrous backfire and you havent pulled the plugs yet to look at them? really?

 

Spraying at low RPM's will cause the backfire.

 

Yeah ive been kinda lazy! My cts-v gets the job done when this rx-8 is down...

 

well stop f-ing posting questions when you havent done the bits you know need to do.

if you know you have fuel then what else do you check?

this is why i keep telling people you have got to ask questions. even the ones you think may be insulting to ask.

will fouled plugs make it hard to start? are you f-ing serious? you had an abnormal combustion event that was forceful enough to blow your manifold. you grabbed another one that "just happens to be laying around at pfs" but you havent looked at your plugs when it wont start?

......../..........

/rant

 

This guy seems extra upset lmao...Well i definitely haven't pulled them yet because i honestly didn't have the time to and having another car allows me to be a little less pressed to have the rx-8 back on the road. I asked a simple question,sorry im not the rx-8 guru lol...dont get ur panties in a bunch buddy..its not ur car.

 

And btw u didnt have to comment on this post if u didnt want to! everyone else answered my questions politely,why cant u do the same?

 

I don't think you realize who it is you're talking to.
Zoom44 = Senior Administrator to this website and a VERY knowledgable person. Keep this up and I see a banhammer in your near future.

What Zoom was telling you is correct, you need to look at those plugs, no sense asking silly questions without doing the obligatory diagnostic first.

 

haha banhammer,as in being banned from the site..oh no i dont want that! im sorry zoom44 ur tha man...

 

this is what i learned from you at dyno day. do not spray under 4500. that is my rule. seems to be working. i get crazy backfire but i always have. since i am catless and have the rb race exhaust

 

it's his fault ^^

 

maybe the others wern't getting it.

you have a NITROUS system on your car yet need to ask if bad/fouled plugs would keep the car from starting. If you cant see the problem there then you shouldnt have nitrous on your car.

you had a drastically abnormal combustion event but havent checked the ignition system. if you cant see the problem with that then you shouldnt have nitrous on your car.

you're going to hurt someone. I have a certain responsibility on these forums to post about things like this in the hopes that others wont repeat them.

 

@Blamerobb is it really a backfire?
Or is it called overrun?

I ask sincerely ....

I thought backfires went .... well .... back up through the UIM (carb/manifold in the old days)?

I know everyone calls them backfires.....

 

1:never did i say that i couldn't see the problem with an ignition malfunction.
2:Ive had fouled plugs before in my V series and it still started,just ran horrible so thats why i asked the question i asked.
3: I understand you are the forum monitor but me asking questions is not gonna hurt anyone..each person is their own individual and i'm not forcing them to do anything. This is the end of my words to you admin because i am not all about this internet arguing. if u have anything else negative to say to or towards me then we can address this in person. I.E. next rx-8 event.

 

yeah you still dont get it. if you have to ask that question you dont know enough about your car(s) to be spraying nitrous in it. the the next time you blow your manifold you or someone else could be standing next to it.

im not "internet arguing" with you I am trying to make you understand how serious you should be about what you are doing.

 

Put this in your gas tank. Will fire right up.