Edelbrocks base tuning is extremely rich out of the box and their AFR targets were insanely rich. With the cats on it, I am targeting 14.7:1 at idle and cruise and 12.5 in power enrichment they call...

When I bought the old girl, the previous owner had removed all the rear seating. I love that it looks like a heavy conversion van on the exterior but it only has the front swivel buckets inside and...

Just an update on this. I swapped the PF4s single plane manifold for a Mercruiser MPI Dual Plane using the rest of the PF4 system and installed old TH315Y Thorley Tri-Ys and put a mandrel bent dual...

7165 can run $12P Holden speed density code.

4K still works ok provided you are not using an electronically shifted transmission. I used the stock 4K one in the cluster on the 87 G20 with the 6.0L and a TH400. Worked well enough to run the IAC...

Some coolant might have hit the ignition coil. I have experienced both TBI and Vortec coils shoring out in the presence of moisture.

They exist in Mexico, just to track one down. They even had manuals in the GMT900 body style down there. 350s in the GMT800s too. There is an OE file for a 250 I6 with TBI for the 7427 that also...

The ECU has nothing to do with the engine cranking over. That is a function of thr VATS module and starter relay.

How can it be closer to a L05? It either has a 305 or a 350.

That being said, cap and rotor, especially the rotor ar suspects. If the rotor has burned through, the spark is grounding out on the...

For retrofits, hard to dismiss Holleys excellent Hydramat product. Had I not looked at a Dorman tank that had a massive baffled area added to it for the G-vans, I would have used a Hydramat for it....

A 2bbl feeds 2 cylinders on each bank from each bore. Some of the TBI manifolds (Edelbrock 3704, GM performance, stock L31 TBI and marine TBI L31) and carb manifolds used with TBI have the cylinders...

Having worked on and driven both the OEM GM TBI and long runner MPFI 250 I6 engines, find a later MPFI intake for a 4.0L and swap to MPFI. The TBI is a good system, but it still has the same issues...

Sure it is getting a reference pulse from the ignition control module. The module can fail, still provide a spark and not send a reference pulse to the ECM. Wiring between the distributor and ECM can...

This exhaust matches the open loop only catless L31. My 2003 L31/5spd 4x4 GMT800 Sonora had the same type of setup but did use front 02s only. Factory EGR deleted, LS truck airbox and 85mm MAF on...

Factory exhaust and 02 configuration on a single catalyst Vortec. 3 pre-cat 02s. An 02 after each manifold and 1 after the Y-pipe. 1 behind the cat.

Incorrect, 3 upstreams on the factory single cat trucks. It very much does change how the engine runs.

GM has factory Express van tunes for L31s with a single cat as well as no cats and even no...

Kickdown mode shifting is activated by a TPS value and hyperstasis value. Usually at some point above ~90% TPS. The kickdown tables are usually a high and low value for each gear. If you have a...

Ducting arrived today, re-tested with the full lengths of 4" ducting. It will be cut to proper length when it is fitted.

https://youtu.be/s6MIf4ckeAE?si=JnvdC8_HneXgL0L5

I do like keeping things under cover as much as possible.

Tested the ram air function earlier with the filter in place. With two scoops in place should be even more effective.
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TunerProRT and an XDF exported from Universal Patcher.

WAG for me tuning my P59 for my L31 style 383 with s marine manifold.

Best thing I can say is mine mostly needed Throttle Stomp Compensation although it did nee aome additional boil time and...

Thank You

I found a NOS, discontinued Spectre air cleaner housing I have had my eyes on. $250 at Summit when Spectre last offered it for $150 on Ebay and it comes with the re-useable 14x4 air cleaner. Seller...

Thanks and they do. Bit of a mystery why long terms and short terms are as far off as they are, but they are correcting in opposite directions and the actual air/fuel ratio is close to the commanded,...

Put a 145 amp AD244 on it and wired it up. Charges perfectly now. 14.5 on a cold start and settles down around 13.8-14.0 when it is hot.