ActuallyaMazda
Member
- Joined
- Mar 16, 2024
- Messages
- 40
- Reaction score
- 36
- Points
- 18
- Location
- Olympia, WA
- Vehicle Year
- 1994
- Make / Model
- Mazda B4000
- Engine Type
- 4.0 V6
- Transmission
- Automatic
- 2WD / 4WD
- 4WD
- Tire Size
- 33’
Hi everyone! I’ve been attempting to hunt down a high idle issue for a week now and I thought I’d post my progress here for some help if possible!
I drive a ‘94 Mazda B4000 4x4 with a 4.0 OHV and an A4LD transmission and the previous owner messed with a bunch of stuff that I’ve been trying to correct over the past year since I bought it.
A week ago today, I cleaned my throttle body with a throttle body safe cleaner we had at the shop that I work at and the issue started when I cranked the vehicle to go home.
Upon startup, the engine started revving like it was a runaway diesel. It held at about 3000rpm while I had it in park and then when I put it in reverse to back out of the shop it dropped down to about 900 where it usually is in reverse. Drive gears is the same way in that it operates seemingly correct under load and at red lights. Even when it is up to temperature, if it is in park or neutral, it idles anywhere from 2000 - 3000rpm.
I have so far replaced the throttle body with a low mileage one from the junkyard, Throttle position sensor, IAC valve, and PCM relay in the last few days after hunting for external vacuum leaks and not finding any using both smoke and starting fluid. I replaced the FPR a couple months ago and thought that it could potentially be an issue with the diaphragm since there are intermittent backfiring issues on warm startup. Vacuum line to Transmission vacuum regulator is all good to the regulator as well. I also replaced two ground bolts that were corroded at G200 and G103.
It sometimes will idle down when cold after shooting to 3k and act like it’s going to run ok and then it shoots back up to at least 2k.
Anyone have any ideas on other things to test/replace? The thing sat out in the woods for god knows how long before I got it and if it needs to be replaced I have no problem doing so.
I drive a ‘94 Mazda B4000 4x4 with a 4.0 OHV and an A4LD transmission and the previous owner messed with a bunch of stuff that I’ve been trying to correct over the past year since I bought it.
A week ago today, I cleaned my throttle body with a throttle body safe cleaner we had at the shop that I work at and the issue started when I cranked the vehicle to go home.
Upon startup, the engine started revving like it was a runaway diesel. It held at about 3000rpm while I had it in park and then when I put it in reverse to back out of the shop it dropped down to about 900 where it usually is in reverse. Drive gears is the same way in that it operates seemingly correct under load and at red lights. Even when it is up to temperature, if it is in park or neutral, it idles anywhere from 2000 - 3000rpm.
I have so far replaced the throttle body with a low mileage one from the junkyard, Throttle position sensor, IAC valve, and PCM relay in the last few days after hunting for external vacuum leaks and not finding any using both smoke and starting fluid. I replaced the FPR a couple months ago and thought that it could potentially be an issue with the diaphragm since there are intermittent backfiring issues on warm startup. Vacuum line to Transmission vacuum regulator is all good to the regulator as well. I also replaced two ground bolts that were corroded at G200 and G103.
It sometimes will idle down when cold after shooting to 3k and act like it’s going to run ok and then it shoots back up to at least 2k.
Anyone have any ideas on other things to test/replace? The thing sat out in the woods for god knows how long before I got it and if it needs to be replaced I have no problem doing so.