EFIDynoTuning Forum

A few times now when towing, fuel cuts off during high temperature climbs above ~225f. I thought it was my fuel pump, but it happens even when enriching at 200 ad counts. As soon as I let off the pedal it goes back to closed loop and runs fine. It also pulls just fine at wot and normal temps. Any ideas??

It's like it's hotter than I thought. FN325 was setting 1.992 lambse above 242 degrees. Time to go back to mechanical cooling fan. These grades around here are stupid long and steep.

Your welcome. Had not overheat protection been in there you would have lost the engine.

Thanks brother!

what are you running for an electric fan?

You'll also want to make sure the radiator is "newish" condition when towing like that. Thanks to Decipha for the protection mode!

When I had to replace my radiator in my 2000 f150, I replaced it with a radiator from a f150 with a 5.4 it had larger tanks, and more tubes, but took up the same foot print. I wonder if a radiator from a f350 with 460 fits in place of a sbf in your model truck? Something to consider if you have to replace. Cheap upgrades using factory parts.

I had a nice 4-row aluminum unit with large tanks. Did a decent job with the dual 90w fans but first and second started leaking within months. After giving up fighting with the manufacturer, went back to a standard AutoZone unit with a lifetime warranty. The dual 90 W fans no longer could keep it cool when towing. Put on the stock fan with fan clutch and it's staying much cooler now.

looking at it a different way. Marine diesels are turned up much higher than road going models. simple reason they have endless cool water to tame the heat built up. On-road stuff can only give off so much heat through the rad before it loses ground and runs hot. Each combo will have some kind of upper limit to the sustained power the rad can cool off.

I like to use the nidrange torque instead of high rpm power. I'll manually pick a gear that lets her climb at 2900-3400 rpm.

I am going to advance the tfs1 cam and Install it at 100icl. Hoping it will bring the power band down into the range you mentioned. Right now it pulls nicely above 3400rpm