Just got finished with an ax15 swap. After everything got bolted back up I took it out for a test drive. It starts and revs in neutral or with the clutch in just fine. Once you get into gear and put load on the motor it just wont accelerate. If you barely put your foot on the pedal it will very slowly accelerate. But if you put anything more than 10% throttle it will just choke and hesitate. Not to mention it runs a bit rougher than usual, it feels like there's too much back pressure in the exhaust, but I'm guessing its probably a vacuum line disconnected. Any Ideas?
-
Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.
wont accelerate
- Thread starter DT|Ac1d
- Start date
joe_peters
NAXJA Forum User
- Location
- Grants Pass, OryGun
Year?
Did you change the PCM/ECU? I know for sure that some years have different part numbers for auto/manual.
TPS? Tested or adjusted? You can adjust the Renix era TPS (pesky year thing again).
Did you change the PCM/ECU? I know for sure that some years have different part numbers for auto/manual.
TPS? Tested or adjusted? You can adjust the Renix era TPS (pesky year thing again).
XJPhoenix
NAXJA Forum User
- Location
- Guelph, Ontario, Canada
IIRC 97 and up XJ's (maybe 96's as well) have the AW4 Tranny control computer and Engine computer talk to one another... If it is a newer XJ, did you change the computer?
old_man
NAXJA Forum User
- Location
- Loveland, Colorado
Sounds like a bad TPS.
joe_peters
NAXJA Forum User
- Location
- Grants Pass, OryGun
AX15 came out mid-89.
Would have come OEM with a BA10 behind the 4.0 for 87.
I would go along with old_man, test/adjust the TPS, and if that is good you might want to check fuel pressure and delivery.
Would have come OEM with a BA10 behind the 4.0 for 87.
I would go along with old_man, test/adjust the TPS, and if that is good you might want to check fuel pressure and delivery.
birchlakeXJ
NAXJA Forum User
- Location
- Melrose, MN
x3. Test AND adjust your throttle position sensor.
Then test fuel pressure on the schrader valve on the fuel rail with a fuel pressure gauge; compare your readings to factory spec.
Then test fuel pressure on the schrader valve on the fuel rail with a fuel pressure gauge; compare your readings to factory spec.
- Location
- Rainy side of Washington
quick hijack - Just a really ultra stupid question I've been wondering about for a while. I don't see any way to adjust the TPS on an HO (it appears the two bolt holes fit the bolts perfectly), is adjusting the TPS only needed/possible on a Renix setup or am I just not seeing something?
joe_peters
NAXJA Forum User
- Location
- Grants Pass, OryGun
Renix only can be adjusted.
