getting a hesitation at @ 4000-4500rpm on accel, 2.0 d-jet 75, mostly new F.I. stuff , TPS board new etc Options

[DRPHIL914]

After replacing the tps board i no longer get that bucking etc when just cruising along, but i still get this once and a while under heavy load, like acceleration , top end of 3rd or 4th gear.

and i'm wondering since this does not happen when just cruising, that is could be the richness setting of full load from the MPS??

MY MPS is a correct used one- tests good and vac is good.no leak, but i bought used , someone pulled this and re-sealed it, and the epoxy plug is missing, and when i first put it in it was very heavy on the lean setting. I have since adjusted the small screw for the idle and across the board richness. and now have a very steady proper warm idle. could be the full load setting is off, , or could the TPS still not be quite set exact?
(also running a electronic spark module- hot-spark, ) all new plugs wires coil seals etc etc etc, no exhaust leaks- new SSHE with triad exhaust 1 year old.

any other suggestions. - could the advance/timing be off just enough that this would not show unless at full load last timed 250 miles ago was right on, and this was there at that time too.

thank s for advice.

phil

[r_towle]

After replacing the tps board i no longer get that bucking etc when just cruising along, but i still get this once and a while under heavy load, like acceleration , top end of 3rd or 4th gear.

and i'm wondering since this does not happen when just cruising, that is could be the richness setting of full load from the MPS??

MY MPS is a correct used one- tests good and vac is good.no leak, but i bought used , someone pulled this and re-sealed it, and the epoxy plug is missing, and when i first put it in it was very heavy on the lean setting. I have since adjusted the small screw for the idle and across the board richness. and now have a very steady proper warm idle. could be the full load setting is off, , or could the TPS still not be quite set exact?
(also running a electronic spark module- hot-spark, ) all new plugs wires coil seals etc etc etc, no exhaust leaks- new SSHE with triad exhaust 1 year old.

any other suggestions. - could the advance/timing be off just enough that this would not show unless at full load last timed 250 miles ago was right on, and this was there at that time too.

thank s for advice.

phil

Did you adjust the MPS?
I read that you adjusted a screw, and across the board richness...was that on the MPS?

Rich

[DRPHIL914]

After replacing the tps board i no longer get that bucking etc when just cruising along, but i still get this once and a while under heavy load, like acceleration , top end of 3rd or 4th gear.

and i'm wondering since this does not happen when just cruising, that is could be the richness setting of full load from the MPS??

MY MPS is a correct used one- tests good and vac is good.no leak, but i bought used , someone pulled this and re-sealed it, and the epoxy plug is missing, and when i first put it in it was very heavy on the lean setting. I have since adjusted the small screw for the idle and across the board richness. and now have a very steady proper warm idle. could be the full load setting is off, , or could the TPS still not be quite set exact?
(also running a electronic spark module- hot-spark, ) all new plugs wires coil seals etc etc etc, no exhaust leaks- new SSHE with triad exhaust 1 year old.

any other suggestions. - could the advance/timing be off just enough that this would not show unless at full load last timed 250 miles ago was right on, and this was there at that time too.

thank s for advice.

phil

Did you adjust the MPS?
I read that you adjusted a screw, and across the board richness...was that on the MPS?

Rich

yes, - normally i would not mess with such a thing, but since the plug was out and it was way way lean , -as seen by idle and plugs, with tthe advice of an experienced bosch tech, the small interior screw- was adjusted to richen the midrange and idle,but the outer screw that adjusts the full load setting was left as-is, what i need is a A/f meter to see where things are to be sure about the setting- they are kind of expensive.

pw

[ChrisFoley]

...
what i need is a A/f meter to see where things are to be sure about the setting- they are kind of expensive.

I'm very happy with the narrow band Autometer A/F meter installed in my dd.
Price is quite reasonable in comparison to a wideband with digital readout.

[DRPHIL914]

...
what i need is a A/f meter to see where things are to be sure about the setting- they are kind of expensive.

I'm very happy with the narrow band Autometer A/F meter installed in my dd.
Price is quite reasonable in comparison to a wideband with digital readout.

Thanks for the tip, chris. I know that is what I need to get it where it needs to be.
What's the best source, and where is the sensor mount location?

[ChrisFoley]

Thanks for the tip, chris. I know that is what I need to get it where it needs to be.
What's the best source, and where is the sensor mount location?

Amazon has them for $65.
Autometer P/N 3375.
You'll also need the Autometer 2244 Sensor Kit. ($99.95 at Amazon)
The O2 sensor should be after the collector but before the muffler.
A heated sensor only takes a minute or two to reach operating temp and will be accurate even at a long distance from the engine.
You'll need someone to weld a O2 bung (comes with the sensor kit) onto the pipe.
You can get switched power for the heater by soldering a jumper onto socket 12 of the 12 pin connector at the relay board.