Morris
Yoda
Offline
Seriously... I am so frustrated I am considering selling the car.
A little history. My head has been rebuilt TWICE in a year's time. The second rebuilder is supposedly the "best in town." The head has all new components except for the valves which were checked and passed by the rebuilder... And still it exhibits symptoms of poorly sealing or sticking valves! I have spent uncounted hours and $$$s on this stupid head and it still SUCKS!!!
But the most perplexing thing of all is that the head passes a compression and leak down test. And I have removed the springs on the intake valves and checked their motion—they all seem to be moving smoothly and easily.
Here are the symptoms:
On cranking, MAP bounces regularly between 75-80 Kpa.
At idle, vacuum is a bit low (35-39 Kpa... should be 30-33 kpa) and engine vacuum fluctuates violently.
On acceleration, vacuum fluctuates extremely violently. There is a miss between 3000 and 4000rpm on medium to hard acceleration. The miss is accompanied by a sudden 10-15kpa increase in engine vacuum.
Previously, vacuum would smooth out a bit at cruise, but now vacuum is bouncing around quite a bit at cruise, too.
The car has plenty of power, but it's getting crappy gas mileage.
Before I remove the head for the 1000th time, I would like to get some opinions from you guys on what the heck is going on.
Any ideas???
A little history. My head has been rebuilt TWICE in a year's time. The second rebuilder is supposedly the "best in town." The head has all new components except for the valves which were checked and passed by the rebuilder... And still it exhibits symptoms of poorly sealing or sticking valves! I have spent uncounted hours and $$$s on this stupid head and it still SUCKS!!!
But the most perplexing thing of all is that the head passes a compression and leak down test. And I have removed the springs on the intake valves and checked their motion—they all seem to be moving smoothly and easily.
Here are the symptoms:
On cranking, MAP bounces regularly between 75-80 Kpa.
At idle, vacuum is a bit low (35-39 Kpa... should be 30-33 kpa) and engine vacuum fluctuates violently.
On acceleration, vacuum fluctuates extremely violently. There is a miss between 3000 and 4000rpm on medium to hard acceleration. The miss is accompanied by a sudden 10-15kpa increase in engine vacuum.
Previously, vacuum would smooth out a bit at cruise, but now vacuum is bouncing around quite a bit at cruise, too.
The car has plenty of power, but it's getting crappy gas mileage.
Before I remove the head for the 1000th time, I would like to get some opinions from you guys on what the heck is going on.
Any ideas???