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Re: Delco Jeep
Posted: Tue May 26, 2015 12:41 am
by v6bucket
I'm not sure if it is affecting the charge temp, but I have the MAT sensor mounted above the throttle body, not in the manifold, the only spare plug in the manifold has a 1/4" square drive in it & I haven't been able to remove it.
The wideband is mounted in the collector for the front 3 cylinders & the last time it was used on a dyno it was reading spot on.
I still have the Jeep IAC connected & running from the Jeep computer, not the Delco so ignore the steps.
I won't get offended with making changes to the bins, it's been several years since I played around the delco.
No it's not a Holden manifold, it's the Jeep inline 6.
Re: Delco Jeep
Posted: Wed May 27, 2015 7:50 am
by v6bucket
I have used the bin that Dylan posted earlier & logged it from cold start.
If you have a look at when the engine gets around the 1400rpm you'll see that it goes into a lean condition I made a few adjustments to the VE at these points but then it the 100 mark. So I took 10% out the the entire table, added 10% to the "Displacement/inj flow rate(Litres/Grams per sec)" from .1346>.1480, didn't seem to make a lot of difference, so I added another 10% to the "Displacement/inj flow rate(Litres/Grams per sec)" .1480>.1633. This flow rate started at .123 as calculated by the Kinjflow injector calculator v1.01, nothing has changed much.
The timing needs some playing around with but I left it until I sort the lean condition.
This log is with adjustments.
This log has +20%
Hopefully some can spot something going on that shouldn't be.
Re: Delco Jeep
Posted: Wed May 27, 2015 9:10 am
by Holden202T
yeah its certainly a very interesting one.
I'd try putting the whole area where its going lean up to 99 ve and see if it richens at all.
does the jeep have any egr or anything like that which would be opening at a certain rpm by the old computer ?
Re: Delco Jeep
Posted: Wed May 27, 2015 9:27 am
by v6bucket
No egr.
I did try that Holden202T, that's why I kept bumping the injector rate up, as I was showing over 100 in the VE table. Might try disabling the Jeep IAC, maybe it is doing something strange.
Re: Delco Jeep
Posted: Wed May 27, 2015 9:38 am
by Dylan
Is there a reason you can't use the delco for iac?
Re: Delco Jeep
Posted: Wed May 27, 2015 10:27 am
by Holden202T
yeah if you can just get it at a nice idle rpm, then unplug the jeep iac could be worth a try, though I have a feeling any iac change would just make the rpms higher and map sensor should change fueling to suit, whereas your issue is at that load point its too lean.
the thing is though there is a definite increase in map kpa that is when the lean spot occurs but that's more than likely just from the increase in tps....
but yeah certainly need to rule out other stuff .... just out of interest, will it run without the jeep computer at all ? just for a test.
Re: Delco Jeep
Posted: Wed May 27, 2015 11:22 am
by v6bucket
Only reason for the no delco iac, I'm still using this as a daily driver & at the moment I still connect the injectors back to the Jeep ecu so I can get to work, which is 70km round trip. But it's on the list.
If I disconnect the Jeep ecu, I loose the dash(it's all operated via the ecu), Airbags & transmission, although I could use 11P to get the trans control.
Re: Delco Jeep
Posted: Wed May 27, 2015 11:34 am
by Holden202T
I was more just thinking remove the jeep ecu and go for a drive and see if the lean spot stops ... but it wont work too well without a transmission

Re: Delco Jeep
Posted: Wed May 27, 2015 11:52 am
by Dylan
Wonder if you could use the delco to log. Hook up the jeep ecu but have the delco read tps map and wideband.
Just to see what afr's the jeep actually runs.
Re: Delco Jeep
Posted: Wed May 27, 2015 12:14 pm
by Jayme
you need to see if it is a lean condition caused by AE (pedal pump) or static fuelling (VE table). can you use the left foot to hold the brake and keep the jeep in the lean spot of the MAP/RPM at a steady state for a few seconds, and see if it remains lean (Adjust VE) or if it starts lean then comes good (increase AE). there is a good chance your engine just needs more AE than a stock v6. the v6 is really light on AE, most motors ive converted delco onto needs more.