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295 Posts
I have been experiencing hard starting only when really cold, like less than freezing, and only after sitting long enough to cool off to ambient. Didn't have any issues during the recent heatwave of 40-degree temps. It tries to catch, but only stumbles. After as many as 4 tries, it will finally catch, running really rough at first, and smoothing out quickly after that, but I have to feather the throttle to get it to stay running initially. Performance and fuel economy are as good as ever.
Yes, I waited to hear the fuel pump run and shut off, and it does. I checked he hoses, PCV, etc. I took out the 2 year old Autolite copper 22C's and put in a new set of Denso 1T16's to see if any change. None.
Looking at the results of The Search, a lot of votes seem to say crank position sensor. I have over 150,000 miles on it, and the CPS has never been touched. In fact, since I bought it in 1999, the only things that have been touched emissions-wise are the 4 O2 sensors. I haven't seen a check engine light since the O2 sensor replacement 2 years ago, and never prior to that. I haven't cleaned the MAF since I ditched my K&N for a stock paper filter a year ago. The plug wires are 6 year old Motorsports, and the coil packs are original. One thing that happened two years ago, though, is that my tachometer went weird, and finally quit altogether, so that brings me back to possibly the CPS again, if it inputs to the tach through the ECM (???).
So, how does cold weather affect starting? My Fiero (2.8 MPFI V-6) has a cold start injector, but these things don't. Is there something else like that on the 4.6?
Yes, I waited to hear the fuel pump run and shut off, and it does. I checked he hoses, PCV, etc. I took out the 2 year old Autolite copper 22C's and put in a new set of Denso 1T16's to see if any change. None.
Looking at the results of The Search, a lot of votes seem to say crank position sensor. I have over 150,000 miles on it, and the CPS has never been touched. In fact, since I bought it in 1999, the only things that have been touched emissions-wise are the 4 O2 sensors. I haven't seen a check engine light since the O2 sensor replacement 2 years ago, and never prior to that. I haven't cleaned the MAF since I ditched my K&N for a stock paper filter a year ago. The plug wires are 6 year old Motorsports, and the coil packs are original. One thing that happened two years ago, though, is that my tachometer went weird, and finally quit altogether, so that brings me back to possibly the CPS again, if it inputs to the tach through the ECM (???).
So, how does cold weather affect starting? My Fiero (2.8 MPFI V-6) has a cold start injector, but these things don't. Is there something else like that on the 4.6?
