Base Map

[Holmsey]

Hi All, I have put a 1993 Lexus LS400 into my 1960 F100 Truck. It is terrible on fuel. I have code 7 and code 8 flashing. I have reset the TPS, to get it to read no resistance it is fully counter clockwise, it reads continuity at .4mm and open circuit at .8mm, so this should be right but it is fully conterclockwise, is there a way of testing the TPS to see if it is Ok other than this?
Will this code make the ECU run only the base map? If it is running on base map will this effect the economy?
Any advice would be mucho appreciated.

 

[gloverman]

Have you compared the codes to the list on the engine spec's section?

http://www.lextreme.com/Lex DxCode.pdf

I always check the TPS using the live data so you can compare the Idle switch and the TPS percentage. Often the Idle switch is on and the throttle still shows 5-8 percent throttle opening. This can be stuffed ECU , Failed TPS , or wiring issues.

Otherwise checking the idle switch with a test light and then confirming you have around 500mv on the signal wire.

Do you have idling issues so adjusted the throttle stop by any chance?

Good luck

 

[Holmsey]

Hi Golverman. I think I maybe a lost cause I have no idea what this even means ;o) " check the TPS using the live data so you can compare the Idle switch and the TPS percentage"

I do have ilde issues, you advised me what the problem was, but as of yet I cant sort it.

I have screwed up the throttle stop so it idles, but I guess this is a no no. I am a carb and points guy so this really is black magic to me.

If the ECU sees a fault on TPS does it run on base map? will this give me my poor gas milage?
I run on LPG now and it ticks over perfect. it is only when on Petrol that it wont idle.

Also that link doesn't show fault codes 7 and 8 which I was told is TPS and air temp I think?

 

[Holmsey]

Right my apologies... its bloody fault code 78 not 7 and 8 Derrrr fuel pump control..... I run a Mustang fuel tank and pump so will give this fault and also the LPG may cause this fault code..

 

[gloverman]

The fuel pump fault code is nothing to do with the mustang tank and fuel pump. The ecu isn't that clever. It's another wiring fault which in my experience leads to reduced power after a short period of driving. I've fixed a lot of vehicles with this issue too. Sort that when you sort idle wiring.

 

[Holmsey]

Ok cheers. I have a load of other jobs to sort. But should get round to the Truck soon. I have all the wires soldered in place and tucked up under the dash so not looking forward to the task.