My week as a bachelor while Donna is visiting family and friends in upstate New York has been relatively boring. I hit the pickleball courts at the Neil Road Recreation Center on Tuesday, Wednesday and Thursday. It’s been my only social activity. Other than a couple of trips to the grocery store, I’ve just been catching up on a few chores.
On Wednesday morning, I pulled the body work off the Spyder and looked for an intake leak. It’s been misfiring at idle and stumbles on initial acceleration. It seems to me that it’s a lean fuel mixture condition causing one cylinder to misfire. Some guys on the Spyder Lovers forum are trying to convince me it’s spark plug wires or ignition coils causing the misfire.
I don’t think this is the case. Ignition breakdown usually occurs under load. The Spyder misfires at idle and once underway, it runs fine. At wide open throttle, it produces full power and takes off like a rocket. There’s no misfire once the engine gets to 2,500 rpm or so. I’m still convinced it a lean fuel mixture condition.
Another reason I believe it’s fuel mixture is that the problem only occurs once the engine is up to running temperature. On a cold start, it idles fine and there’s no evidence of a misfire. On a cold start, the engine runs in open loop – meaning the signal from the oxygen sensor in the exhaust pipe is ignored and the fuel mixture is richer than the optimum (stoichiometric) value. A cold engine needs a rich fuel mixture. Once the engine has been running for a few minutes, it goes into closed loop – the oxygen sensor signal tells the engine control module if the fuel mixture is correct and the control module adjusts the fuel mixture accordingly.
When I looked at the throttle body on Wednesday, I concentrated on vacuum hoses. I looked for cracks or loose hoses. With the engine running, I sprayed the vacuum lines and fittings with carb cleaner. If there was an intake leak, the vacuum would have sucked the spray cleaner into the intake and the engine would immediately run differently. I didn’t detect any change in the running of the engine. I gave up and reinstalled the body panels and went to play pickleball.
Vacuum hoses on the throttle body
When I played pickleball Thursday afternoon, I felt a twinge in my left leg. It was high in the hamstring – where the muscle inserts below the gluteus. I continued to play and it didn’t bother me too much. After I came home, I really stiffened up and had pain in the upper hamstring area.
I won’t play pickleball today. I’ll rest my leg and see if I can get to the bottom of the misfire issue on the Spyder. Thinking it over, I’m going to take a look at the idle air control valve (IACV) and the associated hoses. When the throttle plates are closed at idle, the IACV controls the air going into the engine and thus the idle speed. If there’s a leak in the system past the IACV, then it cannot properly control the air and fuel mixture. I still have one item to check off Donna’s honey-do list, but I’m going to make the Spyder issue my priority today.
Donna will return tonight – I can’t wait. I hope her flights are on time. She’ll fly from Albany, New York to Las Vegas then on to Reno. We’re booked here at the Sparks Marina RV Park until Monday. The weather this week has been fabulous. Yesterday and today will be the warmest with the temperature reaching the mid 80s. The rest of the week was mid 70s and that’s what the weekend forecast calls for.
We thought about heading up to Lake Tahoe on Monday, but I think it’s still too cold there. The forecast for next week predicts highs in the 50s and 60s with the temperature dropping to freezing overnight. We’ll figure out our next move this weekend.