New to this group and a novice tuner.
Working on a 1999 Dodge Durango SP360.
Running very lean, ie) 17-18 at idle and around mid 20's above 1000rpm.
Has a larger throttle body (plug & play), and 40lb injectors.
Any help in where to start looking would be greatly appreciated.
Thanks
John
If I remember correctly, that setup originally utilizes a Kenne Bell supercharger with 2 additional injectors and a piggyback pc. It sounds like you've deleted the piggyback? I'm pretty green in the tuning world but, share the tune and a data log and the advanced tuners here will give some input. They have helped me bunches with my build.
Thanks for the reply.
Your right it has a Kenne Bell supercharger.
Didn't know about the extra injectors or the piggyback pc.
Got some information from the owner.
Found out that the piggyback pc was bad and someone removed it.
The conjecture in the shop is that the new injectors were to make up for the loss of the two when the pc was removed.
A lot about the car is unknown, was acquired at a auction.
Yeah, that setup when new utilized the original 19 lb/hr injectors. The piggyback controlled the additional 100s on top. With 40s it should work fine but the map sensor will need upgraded and reprogrammed. The Kenne Bell piggyback covered that as well somehow if I remember correctly.
I'm not sure why it would be lean at idle unless maybe the bypass valve was staying closed. You might want to make sure it is working.
Reset adaptives and see if idle straightens out.
What are fuel trims before you reset?
If in doubt, multiply everything by 1.1.
I'm posting the pcm data from the Durango. Hope someone can offer some advice.
The first two attachments are screen shots of the VCM editor display.
The next two attachments are the download of the two PCM shown.
The last attachments is a scan of the car running at startup, not driven.
Hope this helps.
Thanks again, John
Disregard my previous mention of the bypass valve. The ecm may need programmed for the new injector size.
Well, looking at the log file, adaptive trims definitely swing as soon as it goes to closed loop.
Do you have a wideband on it?
If in doubt, multiply everything by 1.1.
Yes, the car has a wideband installed.
More info on the injectors: Holley 250R150A 42lb/hr
Setup the wide band to log with VCM scanner. Hopefully, your wide band controller has an output and the cord. My wideband cord was a db9 connector so I had to get a DB9 to USB cord.
Definitely watch pulsewidth, the wideband and fuel trims and you can see what's happening.
But also, reset adaptives and see if it improves.
If in doubt, multiply everything by 1.1.
John,
What type of wideband does it have?
I am tuning a similar platform, 408 Magnum and at idle in park my AFR is really high. In gear it is fine. My LTFTs go to 0 when in park and that increases my AFRs.
have posted 2bar boost tune for a dakota , if you search you find it
Did you correct your battery voltage offset for the 42 lb. injectors. i looked at your posted files and it was different from both new and old style Holley 42 lb injectors. I didn't look up your specific part number. I would enter correct injector values first, then adjust fuel table at the map your truck idles at, appears you have the stock or near stock cam in it, or your map isn't reading correctly.
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