Ok first time post..and first time mazda owner..
I have 1999 BJ 1.5L auto has the variable valve timing by the look of it!
Bought it cheap with no spark
Found setting crank sensor gap to spec and started perfect to idle
However under load just of throttle serious hesitation with occassional intake backfire. On the road from part to near full throttle the hesitation will disappear and it will pull hard to redline with ease virtually hesitation free
Ive swapped over both coil packs, plugs from a wreck, previous owner replaced cam sensor and crank sensor and the I tried another ECU and absolutelty no change.
Its OBD1 and I havent pulled the codes yet as Im away from the car at the moment but next thing is new MAF but im doubting that..I cleaned it.. Ive had the fuel pump out to check in there and looks good lol..couldnt see the high pressure filter but as it pull hard under full throttle i doubt its fuel pressure.
Just wondered if anything silly Im missing..engine coolant sensor, O2 sensor,
When I get home Ill investigate further..Ill have another Maf and TPs to try also Ive got an oscilloscope I tocheck signals to ECU etc.. Its weird..just idles perfect..soon as the gap on ckp set away it went
**UPDATED**
Ok so now the car still has the issue but is a little better
It produces no fault codes..(obd2 4 digit with the early connector under hood)
What it does now is idles perfect, but at part throttle say 1/4, if you hold it there it will cycle the revs up and down.open it over half away it goes
If you unplug TPS it will stop reving up and down
Checked TPS, resistance and voltages normal
No codes
Looked for vac leaks..seems ok
Plugs burning mixture properly
WOT and it goes well..VVT seems to work ok as pulls hard
Tried..New battery, terminals, air filter, swapped another MAF, coils, PCM, HT leads, cam sensor, CKP. Had the fuel pump out to have a look clean in there..pump not noisy..yet to test fuel pressure but dont think is this
Any ideas?
I have 1999 BJ 1.5L auto has the variable valve timing by the look of it!
Bought it cheap with no spark
Found setting crank sensor gap to spec and started perfect to idle
However under load just of throttle serious hesitation with occassional intake backfire. On the road from part to near full throttle the hesitation will disappear and it will pull hard to redline with ease virtually hesitation free
Ive swapped over both coil packs, plugs from a wreck, previous owner replaced cam sensor and crank sensor and the I tried another ECU and absolutelty no change.
Its OBD1 and I havent pulled the codes yet as Im away from the car at the moment but next thing is new MAF but im doubting that..I cleaned it.. Ive had the fuel pump out to check in there and looks good lol..couldnt see the high pressure filter but as it pull hard under full throttle i doubt its fuel pressure.
Just wondered if anything silly Im missing..engine coolant sensor, O2 sensor,
When I get home Ill investigate further..Ill have another Maf and TPs to try also Ive got an oscilloscope I tocheck signals to ECU etc.. Its weird..just idles perfect..soon as the gap on ckp set away it went
**UPDATED**
Ok so now the car still has the issue but is a little better
It produces no fault codes..(obd2 4 digit with the early connector under hood)
What it does now is idles perfect, but at part throttle say 1/4, if you hold it there it will cycle the revs up and down.open it over half away it goes
If you unplug TPS it will stop reving up and down
Checked TPS, resistance and voltages normal
No codes
Looked for vac leaks..seems ok
Plugs burning mixture properly
WOT and it goes well..VVT seems to work ok as pulls hard
Tried..New battery, terminals, air filter, swapped another MAF, coils, PCM, HT leads, cam sensor, CKP. Had the fuel pump out to have a look clean in there..pump not noisy..yet to test fuel pressure but dont think is this
Any ideas?