My truck started running poorly a few weeks ago. It had a fit and barely idled at lunch, I drove through the miss and then it started being normal again for a few weeks. In the last two days I really thought I got a bad tank of fuel. Found good gas, put some MMO in the tank and it seemed to get better. Then, the following morning it was acting up.
I can’t tip in off idle without the truck bucking and it feels down on power. Then randomly it will drive normal and pull solidly throughout the rpm range.
I’m caught up on all the maintenance, it’s got 20 in Hg of vacuum at idle, and it’s dead stable. The initial pump shot on the carb is working and there’s fuel in the bowl.
I’m starting to wonder if I’m chasing a temperature dependent vacuum leak. This intake has cracked before and i had it repaired when I redid the top end.
What have you all had happen when there was a confirmed intake crack found? This seems too intermittent to be a fuel or a spark related issue. The truck is desmogged so that’s not an issue that’s making things worse. I just think i need to keep chasing loose bolts and vacuum leaks before I do any parts swapping.
I can’t tip in off idle without the truck bucking and it feels down on power. Then randomly it will drive normal and pull solidly throughout the rpm range.
I’m caught up on all the maintenance, it’s got 20 in Hg of vacuum at idle, and it’s dead stable. The initial pump shot on the carb is working and there’s fuel in the bowl.
I’m starting to wonder if I’m chasing a temperature dependent vacuum leak. This intake has cracked before and i had it repaired when I redid the top end.
What have you all had happen when there was a confirmed intake crack found? This seems too intermittent to be a fuel or a spark related issue. The truck is desmogged so that’s not an issue that’s making things worse. I just think i need to keep chasing loose bolts and vacuum leaks before I do any parts swapping.