Page 1 of 2

K8 very rough from above idle to 2,000 rpm SOLVED!

Posted: July 3rd, 2008, 12:59 am
by fowljesse
My K8 stopped running after I did a compression test, at which time, I unplugged the fuel rails, but forgot to stop the fuel pump. I replaced the coolant temp sensor, because I broke it, and the disty because I thought it was the problem. Then I got the other MX-3, and let the K8 one sit for about 5 months. I looked into it again yesterday, and the timing was way off, so I set it, and now it idles fine, but almost dies with any throttle, unless I barely feather it. If I let out the clutch, it almost dies, unless it's above 2,000 rpm. It drives fine at partial throttle, as long as it doesn't drop below 2,000 rpm, and I keep the throttle light..
I'm going to swap in a good MAF, when I can get one (in about a week).
Any other ideas?

EDIT: It was the distributor.

Re: K8 very rough from above idle to 2,000 rpm

Posted: July 3rd, 2008, 9:43 am
by FlyVFR
Sounds like the old crack in the TB Fresh air intake rubber hose. :evil:

BTW, if you need a JE50 I have one listed FS

Re: K8 very rough from above idle to 2,000 rpm

Posted: July 3rd, 2008, 4:17 pm
by fowljesse
Thanks, but, I've got a solid CAI with no leaks, and Mooneggs is going to let me borrow his, and buy it, if needed.

Re: K8 very rough from above idle to 2,000 rpm

Posted: July 3rd, 2008, 6:15 pm
by shameem
Drain all old gas and run some injector (or fuel system) cleaner. If you have the injectors out - its a good idea to clean them with some acetone or something..... If you had the fuel lines open to air (after filter) make sure you clean them and possibly change the fuel filter.
Since it had been sitting - check oil level/condition....

Re: K8 very rough from above idle to 2,000 rpm

Posted: July 3rd, 2008, 6:24 pm
by fowljesse
Cool. Thanks. I'll do it.
I changed the filter while it was down.

Re: K8 very rough from above idle to 2,000 rpm

Posted: February 17th, 2009, 3:05 pm
by tmac4t4
wondering how this turned out for you? just picked up a 300 dollar mx3 that "apparently" needs a head gasket..but doesnt show any signs of actually needing one, other than the fact it runs like you described...it has a total makeshift intake consisting of exhaust tubing coming off the throttle body bent to a 90, connected to the vaf/cone..i noticed the piping was quite warm after it ran so im thinking he cooked the sensor? that and its upside down.

Re: K8 very rough from above idle to 2,000 rpm

Posted: February 17th, 2009, 11:09 pm
by fowljesse
Sorry. I thought I concluded this.
It turned out I had a bad distributer that got weak at higher rpm. I put in a good one, and voila! The car has driven great since then :)

Re: K8 very rough from above idle to 2,000 rpm

Posted: February 18th, 2009, 8:12 pm
by tmac4t4
thanks..ill check that...i know its something stupid and small like that.

Re: K8 very rough from above idle to 2,000 rpm

Posted: February 18th, 2009, 8:17 pm
by Daninski
Ahh, another happy ending. I love this kind of story.

Re: K8 very rough from above idle to 2,000 rpm

Posted: February 19th, 2009, 1:40 am
by RX8SE3P
Yeah bad disty can do that.

I tried out a probe disty on my MX3 and it idled fine for a while then would just die. Then I couldn't get it to stay on, kept stalling and then when it misfired once it was obvious that the disty was crap and when it got hot it stopped working.

Re: K8 very rough from above idle to 2,000 rpm

Posted: February 19th, 2009, 1:45 am
by Flyer
the K8 is telling you to replace it ith a KL...

Re: K8 very rough from above idle to 2,000 rpm

Posted: February 22nd, 2009, 1:15 am
by tmac4t4
lol it sure is...

i had a better chance to drive the car today and find out exactly how it runs (since it was stored in another city)..it idles very low, at like 400-500 rpm..it idles fairly smoothly though and it wont stall..however the moment u give it gas it bogs until right around 2500rpm..than it pulls hard like theres nothing wrong at all..until you get up to about 5500rpm..than it starts to bog again..i was told it needed head gasket, but it shows no signs of needing one....especially with how strong it runs between those rpms. does this sound like a maf or disty issue?.im leaning tworards the timing being off?? it backfired once one me so that makes me think..i want to do the klze swap but if i can get this thing running right (for cheap) than it means i can put even more $$ into the swap :welder:

Re: K8 very rough from above idle to 2,000 rpm

Posted: February 22nd, 2009, 12:16 pm
by fowljesse
I'm thinking spark issue.. It could backfire if unburned gas ignites in the exhaust, and unburned gas would be there if there is a spark issue. However, if there's a MAF issue, it could be dumping gas in there.
I think you should read your spark plugs.

Re: K8 very rough from above idle to 2,000 rpm

Posted: February 22nd, 2009, 6:43 pm
by tmac4t4
plugs/wires/cap all brand new..from what i was told..the timing belt was replaced a few weeks ago, than it started to run rough..so his mechanic told him it needed a tune up..so that was done..and the problem didnt go away..so the mechanic told him its a head gasket..i have bills for all the parts replaced and if you ask me the mechanic was taking this guy for a ride. :shrug:..it has to be a timing issue?! :confused2:

*EDIT*..rummaging through the reciepts again, i found a peice of paper with instructions on how to install one of those nifty hightech resistor mods on the IAT/CTS.. :crying:...i guess ill be looking for that as soon as i get some day light..ill be sure to throw it as far away from the car as possible once i find it too.

Re: K8 very rough from above idle to 2,000 rpm

Posted: May 18th, 2009, 8:56 pm
by JHZ
Did you manage to solve this mate? My K8 has exactly the same problem and it's driving me nuts.