old_man
NAXJA Forum User
- Location
- Loveland, Colorado
My rig has been slowly losing power and the fuel mileage has gotten down to around 12mpg. It is a 4.7L stroker and used to get 20mpg. It is not misfiring and idles real smooth.
I reconnected my AFR gauge and started monitoring how it was doing. At first I noticed that things would be good for a while then the AFR would drop to 10.0 and stay there. There was little rhyme or reason as to when it happened, other than most time is happened when I took my foot off the throttle for a second or slowed down. I replaced the O2 relay and things got better, but it still runs at 10 around town and below probably 55 mph.
In closed loop, the AFR ranges from 13.4 to around 15.
The compression is still great. I checked the coolant and intake temp sensors. Both were reading correctly. No vacuum leaks. I double checked the MAP and it's variable supply. It has a bored throttle body and I checked the TPS. The plugs look good.
Is this normal for the Renix? I don't remember this when I built my stroker 15 years ago. When yours goes closed loop, does it stay that way around town or at low speeds?
I am going to monitor the vacuum, looking for a clogged CAT and see if it tracks the readings.
I wouldn't be all that hot to fix the issue, but I have to pass a smog test soon.
I reconnected my AFR gauge and started monitoring how it was doing. At first I noticed that things would be good for a while then the AFR would drop to 10.0 and stay there. There was little rhyme or reason as to when it happened, other than most time is happened when I took my foot off the throttle for a second or slowed down. I replaced the O2 relay and things got better, but it still runs at 10 around town and below probably 55 mph.
In closed loop, the AFR ranges from 13.4 to around 15.
The compression is still great. I checked the coolant and intake temp sensors. Both were reading correctly. No vacuum leaks. I double checked the MAP and it's variable supply. It has a bored throttle body and I checked the TPS. The plugs look good.
Is this normal for the Renix? I don't remember this when I built my stroker 15 years ago. When yours goes closed loop, does it stay that way around town or at low speeds?
I am going to monitor the vacuum, looking for a clogged CAT and see if it tracks the readings.
I wouldn't be all that hot to fix the issue, but I have to pass a smog test soon.