Runs terrible after warmed up crazy tachometer VIDEO

[pauleatstoomuch]

Ok, so here is a new topic with a new view. The history of the car: The body is a 1994 with 94 ecu and wiring harness. The car did not run when I bought it. I installed a fully rebuilt 1995 B6 dohc with new: oil pump, water pump, plugs, wires, cap and rotor, pcv valve, swapped throttle body with IAC and TPS, short ram air, new timing belt and pulleys, and temperature sensor. Compression = ~ 150psi. Fuel filter is a year and half old as is the o2 sensor. I gutted the catalytic converter, and have run injector cleaner. I also cleaned the Mass Air sensor with cleaner.

It only acts like this after about 20 mins when it's warmed up. The ignition timing is good (I have a timing light). I am stumped. Here is a video of me accelerating 0-60 at WOT, and the tach jumps like crazy, it runs like crap, and I am getting horrible gas mileage.

http://www.youtube.com/watch?v=TFpLqqqIfAU" onclick="window.open(this.href);return false;

HELP!!!

Thanks!

[SuperK]

the timing belt can be set incorrectly, I would remove the cover and make sure they align correctly with the timing marks.

Try swapping distributors themselves with your 94

and unplug the o2 sensor.

that's my starting point suggestion

[pauleatstoomuch]

Ok, I have already unplugged the o2 sensor, still does it. I already swapped distributors, still does it. I will check the timing belt later.

[wytbishop]

The tach signal comes from the distributor. The distributor also definitely explains the poor running. I don't see how it could really be anything else.

[pauleatstoomuch]

I thought it may be the timing belt (maybe skipped a tooth), but I would think it would run poorly all the time, but it only does after it's warmed up. Should I start with just a cap and rotor? The one I have is about a year old. Also, should I go for the 4 cyl HEI mod?

[wytbishop]

If you can, get a disty off of a working 94'. You're using the 94' harness so its looking for a 94' distributor. Try to find a 94' in your area that is stock and running properly and just swap it in and see if it works. I'm betting it will. Did you modify the harness at all when you swapped the 95' motor in? Are you running a 94' or 95' distributor. I'm not an expert on the differences in the RS from year to year, but there's a good chance things are different.

Other possibility is the thottle body. When its cold the ECU is dumping in lots of fuel but when it warms up it naturally idles down. If the fuel pump is weak or something in the throttle body isn't right it could cause it to sputter.

My money is still on Disty though.

[SuperK]

94 or 95 doesn't matter in year, wyt. A disty for the B6DE is a disty is a disty. we've tried a 95 in a 94 in a 95 in a kia sephia (the rare B6DE version) disty and the other way around. 'dem same tings. friend's running the sephia disty in his 94 B6 and it's running like a champ.

[wytbishop]

Well in that case I would just quickly try a disty from a running B6 and see if that solves it.

[SuperK]

there was mention he already tried swapping disties... of course, can't confirm if either of them is working properly. Some people's luck, they'll have two parts with the exact issue.

[Ryan]

I've had that! got a disty that I pulled from an MX6 that I watched running healthy....

put it in my MX.... no go.

MX6 was now dismantled.

[wytbishop]

There is an outside possibility that it’s related to fuel delivery, but I can’t really see it. Does the B6 use a crank angle sensor for ignition? Could be a bad sensor outside the disty that’s affecting ignition. Says he replaced the plugs and wires but maybe he’s got a broken plug wire boot or just a bad wire.

I dunno...it sure sounds like a bad igniter to me. I would still want to put a disty on from a car that I knew was working well. This problem really screams distributor to me.

[SuperK]

You are in charge of selling my stuff wyt. You heard the man he said buy my distributor!

[pauleatstoomuch]

So, SuperK, how much do you want for your disty? shipped to 34606
Thanks for your help everyone.

[pauleatstoomuch]

Ok, so I drove 50 miles each way today, and the tach did not jump at all. It ran pretty well. I swapped out the ECU, and I used 93 octane gas. It still is only getting about 23 mpg city and 27 mpg hwy (75mph). Should I take off the valve cover and timing cover to see if the timing belt may be off by a tooth. I can't get the timing marks on the crank pulley to line up perfectly, although it is very close. The disty won't advance further. Does this sound like a timing belt issue?

[wytbishop]

if the timing belt was a tooth of it would run very rough, if it ran at all. The ECU could have been the cause of the crazy tach but if the fuel cosumption is still high i'd say it's likely a separate issue. Keep driving it for a while and make sure the tach issue is resolved...then we'll talk fuel.