engine misses @ WOT

[turbo497]

engine breaks up at full boost and acceleration from rolling start. Are there any areas I should look at first. I am not throwing codes

 

[shrp1]

It would help to know what if any mods you have, how much boost youre running and what type gas. Do you have a scan tool? How long since last tune up?? Email private if you want

 

[turbo497]

I'm running an atr pit bull @19.5 pounds boost in 1st gear. mods are ATR pit bull, K&N filter the rest of the car is stock. I have changed the timing chain coil pack and crank sensor, TPS postion switch since I bought the car.

 

[ChrisK]

Test the COIL PACK. Use an OHM Meter. It happened to me once to...

 

[shrp1]

You need to be running some DAM GOOD gas with that chip!!!!!!!!!!!!!

What I would do is LOWER the BOOST to around the stock level, change the plugs and fuel filter and run it again. Then if all is well slowly bring boost back up. While your at it check the plug wire resistance, should be less than 1K ohm, if they are not replce them. Ohm the Coil pack while your there also, 11K-13K across each coil.

Other alternative is put the stock chip back in and test to see if its still missing at WOT.

Good Luck

 

[turbo497]

ran ohm meter on sparkplug wires looks as though they are bad. all more than 1k ohm will change them and test. I do have a question to test coil pack where I'm I placing the other lead --To ground???

 

[shrp1]

Measure the ACORSS each coil, the coil pack has 3 coils. So the front and back point where the spark plug wires attach.

Phil

 

[1badTTA]

test across each of the 3 coils, you should get 13K ohms

 

[2QUIK6]

Do you have a scan tool?
Any knock (KR) when it starts cutting out?
MAF readings?
O2 readings?
Coil pack should be 11k-13k ohms measured across corresponding posts, but the ignition pack could still be bad, of a plug wire may not be making good contact or corrodded.
I had 2 wires not on tight on the coil pack and they were a little corrodded, and it caused severe sputtering trying to accellerate at any degree. Cleaned them up and crimped the terminal connectors a little tighter and now it runs great.

 

[turbo497]

I did find some corrosion on the coil pack terminals- I cleaned them and r/r plugs and wires. I still have a slight breakup on full boost It may be a crack wastegate hose I will check it soon

 

[Up N Smoke]

I have had that problem for the longest time.. it seemed to overboost and detonate. I have a THDP, TA-49, K & N intake, and an ATR chip. Try adding a little octane boost, seriously it made all the difference in my car. Some of the turbo cars are more sensitive to octane levels. Give it a shot... could be a cheap Fix! Good Luck!
Drew

 

[CanadianTTA]

That is true! Different turbos require different amounts of octane to achieve maximum powere and efficiency, the larger the turbo, the less boost needed to move the same amount of air as the stock turbo! That means that 20 psi of boost with the stock turbo would require less octane than lets say 18 psi with a larger turbo, does this make any sense to you? You need a scan tool to tell you what the engine is doing when tuning like this!

 

[turbo497]

the car was over boosting due to old wastegate hoses. put on a new hose with adjustable needle valve and turned the boost down