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bubb, the real one 08-27-2018 01:55 PM

new injectors and increasing fuel flow
I have a 1990, 7.3 manually aspirated engine, 37ft bus, 170k miles

A mechanic I know said that by getting new injectors and increasing the fuel flow a little, I can get a little more power, also said it would smoke a little more but mostly on a hard acceleration or on hills,
Do you agree, anything else to consider before doing this.

gbstewart 08-27-2018 02:42 PM

i replaced all of my injectors , 1999 t444e = 7.3 turbo, I went with stock size, and yes it did wake the old girl up a bit, plus I had no more blue smoke. With that being said my old injectors where worn out. You can put bigger injectors in that will give you more performance, but that would burn more fuel, and maybe harder on the motor. For that reason I stayed stock, and I did gain almost 1 more mpg.

brokedown 08-27-2018 04:14 PM

My understanding is that the easiest way to get more power out of a 7.3 IDI is to add a turbo. Ford produced it with a turbo for a short period of time, so the parts exist. They're too high compression to boost to the sky but 6 or 8 psi would likely be long term safe.

He's a good reference on 7.3 IDI performance:

6.9L & 7.3L IDI Performance Upgrade Options

Tango 08-27-2018 04:35 PM

If you're gonna add a turbo...add a CAC (Charge Air Cooler).

magnakansas 08-27-2018 07:38 PM

the good the bad and a way
The good, yes you can "turn up the fuel" or add fuel and get more power.

the bad, When you start making smoke out the exhaust you also start running hotter exhaust temperatures. Get hot enough for long enough and you will damage engine parts.

Back in the day when these engines were new, turbo kits were sold to get more poop out of them with out killing them too quickly. By adding a turbo, with an intercooler, and turning up the fuel a little, you will get more poop, keep exhaust temps down, and a cleaner exhaust. The internet was not much of a thing at this point in time and most of the message boards that were active about this are now thirty years old, There should be books and some internet information about safely adding fuel, turbo, and intercooler. I would guess you could do as much as 100 hp and 150 ft lbs of torque and not put too much stress on the engine, but I dont really know for sure. I have an 89 uhaul with the 6.9 non turbo diesel and have looked into "turning up the fuel" but will probably install 95 or newer 7.3 instead and then add fuel/turbo/intercooler.


Tango 08-27-2018 09:27 PM

Most diesels can be pumped up quite significantly via the fuel (smoke screw) and timing. But you definitely need to know the parameters for your engine before diving in.

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