bucking hard.any help?
#1
bucking hard.any help?
Alright so, I have replaced the top end of my motor, 95 5.0 gt, I replaced the heads with gt40y ported, tfs2 cam, 1.6rr. cobra intake, 75 tb new oem maf, tune up. Thats about it. When the rpms are below 3000ish it bucks hard, but if I push the throttle all the way down then it picks up speed and doesnt buck. I have not driven it much but it seems to do worse when i am coasting in 4th gear. Firing order is correct, and I have no vacuum leaks. Thanks!
#2
Thats right in the RPM range of EGR related issues that can cause a buck. The valve gets a bit of carbon in it and it makes the sensor about 10% off from where the ECM is expecting and the bucking is the vacuum solenoid trying to correct that.
#6
#10
Test it first. Generally if the EGR is the cause, the CEL will flash on momentarily while the problem is occuring, and turn off as soon as it goes away. A quick fix is to take the sensor off the EGR and take the pintle to a grinding wheel. Shave a couple millimeters off it and that will allow it to fall into a rested position, fixing the code issue and bucking. It will only solve it if it's truly the problem, though. If you shave the pintle and the EGR isn't the problem, you've just added a 10% correction in the other direction, effectively creating a problem that wasn't there before.
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