94 motor, 92 computer

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Dec 10, 2007 | 10:41 AM

Fanboy

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94 motor, 92 computer

Probably a simple question but here i go anyways. I finally got my truck running after having to do an engine swap. Aside from the never ending cooling issue, everything seems to run really well. The only exception is the gas mileage, it still seems to be a little excessive, even after chaning everything associated with the fuel and emissions equipment. I was wondering if the 92 ecu, is causing the 94 motor to run a little richer than it should. What can i do to fix this aside from buying a 94 ecu?

Thanks

Dec 10, 2007 | 11:21 AM

Conanski

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From: Ottawa, Ontario

If the engine sensors are all connected and operating properly the fuel milage should be about the same as the other motor. What milage are you getting, and does the computer throw any codes? Have you checked fuel pressure?

Dec 10, 2007 | 11:36 AM

Fanboy

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I am not exactly sure what milage i am getting, however this is the first time that i have been able to watch a gas gauge move. But as an example, a five mile round trip in town will eat just under an 1/8th of a tank of gas. The computer hasn't thrown any codes, however if i do a koeo or koer test with my scanner, i get that the evap system is below voltage spec at idle. I also get two codes that say the idle is to high, and also to low. The fuel pressure checked out fine once i installed a new fuel filter, the PO put the last one in backwards. I have also replaced the EGR valve, and sensor, fuel pressure regulator, O2 sensor and everty vacuum line.

Dec 10, 2007 | 11:50 AM

Conanski

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From: Ottawa, Ontario

You'll have to run a couple tanks of gas through it to get an accurate milage indication. Does the truck have dual tanks? If so it could be pumping gas to the other tank and making the milage look much worse than it is.

Dec 10, 2007 | 12:30 PM

Fanboy

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No just a single tank.

Dec 10, 2007 | 05:15 PM

lostin90s

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From: Central PA

If you did a 351 dont bother to read this below .

Well if you r dealing with a 302 . They changed firing order to the 351 order in late 93 (had 5 93 with old order ) . So even batch injection the firing of injectors will not match the cam order (basicalkly pushing gas out exhaust (I learned the hard way ). If this is so get a 94 engine harness. Fenderwell to engine. The sensors r same but you will want to check all conections at plug to see if there are pins to be switched .

Dec 10, 2007 | 06:47 PM

Fanboy

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I have the harness for the 94 engine in the truck, and the firing order that was on the motor when i got it matched the 92 firing order. Regardless what is the correct firing order????

Thanks!