new engine installed, not running well

Red_MX3_92 · Post by **Red_MX3_92** » June 11th, 2007, 6:53 pm

Hey guys i have a 95 mx3 dohc 5spd and in the past 3 days me and my brother have put a 94 dohc auto engine i was so happy to hear it purr(my cars still 5spd switched trannys) but then i noticed a idle problem running around 300-500 rpm then after i give it gas its like it was backfiring or somthing through the air box caz i just here a little bank once and a while, and then i took it for a spin up and down my driveway and its got a massive power loss, then the next thing i noticed after the drive the cat was blazing red! pls help me out this is my comuter car and now im missing school. thanks guys

mr1in6billion · Post by **mr1in6billion** » June 11th, 2007, 7:23 pm

You're running lean. Check all your fuel related items, including spark plugs and O2 sensor.

Red_MX3_92 · Post by **Red_MX3_92** » June 11th, 2007, 7:40 pm

the fuel should be ok unless i got the return line mixed up with the other feul line but i dun think so, then i checked the spark plugs they were ok the far left and right was covered in oil just the thread and just a bit tho, the 2 middle cylinders were fine, the o2 sensor i didn't check yet.

Red_MX3_92 · Post by **Red_MX3_92** » June 11th, 2007, 7:50 pm

forgot to mention theres like a anoying buzzing inside at the passanger side near the ecu or around there

Red_MX3_92 · Post by **Red_MX3_92** » June 11th, 2007, 8:35 pm

ok guys stupid me mixed up the spark plug wires at the distributor now its all good just the rpm goes down somtime a bit to 500 from the normal 700, what can that be, and when i switch from 1st to 2nd 2nd likes to slip a bit i hope that wears out.

Red_MX3_92 · Post by **Red_MX3_92** » June 15th, 2007, 4:36 pm

yea theres a new problem now, i think it might be a air leak somewhere, what happens is when i drive and let go of gas(cruise) then when i apply the acceleration again it chokes a bit and then works, and after i drove it for a while when i accelerate from 1st to 2nd and 2nd to 3rd at low rpms to kinda chokes a bit, what can that be? as well i just recntly got a gas smell going outa there where can that be from because its not the lines or injectors

Red_MX3_92 · Post by **Red_MX3_92** » June 17th, 2007, 1:33 pm

R0MEO · Post by **R0MEO** » June 17th, 2007, 8:33 pm

I had a similar problem in my old 85 Jetta..
basically what it seems like to me is that you have oil getting into your air system, which causes the car to give a shake or choke as you said. which can also be the problem for your low RPM's as well. not sure if it's exact with jetta's and mazda's but that's what happend with my other ride, so I had to scrap it.. Money wasn't coming in anymore.
so check your air system, oil filters and make sure you dont have oil getting into your air system.