aniesigh Posted August 21, 2014 Share Posted August 21, 2014 Hi all, Fitted a 3.9 serp v8 from a 300tdi shape disco to my mates challenge truck a while back, also megajolted it at the same time. Truck is coming to the end of its build and have a few loose ends to tie up, so i have a few Q's. I didnt take the engine out of the donor truck myself else i would have the answers to some of the Q's! Firstly... its one of the models with no tune resistor, but we want to run one so we can not bother with Lambda sensors. Can we just put the appropriate value resistor between the relevant pins on the ECU or do the ECU's that don't have tune resistors only have one map in them? Secondly.... am i right in thinking the two hose fittings under the TPS would usually be connected into the cooling circuit? if so will it cause any real harm to just ignore them? Thirdly (and lastly i think) there are 2 10mm ish size hose fittings on the inlet manifold. if i remember correctly, one is on the left hand side of the plenum, cant remember where the other one was. What would they have been for and again can they be blanked? Cheers Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted August 22, 2014 Share Posted August 22, 2014 1 - Dunno 2 - Correct, no it won't do any harm but the small pipe they are fed from on the inlet manifold should connect into the little bleed hose off the top of the rad to help bleed bubbles out of the cooling system as it's a high point. 3 - Brake servo vacuum and maybe cruise control or fuel vapour capture canister or somesuch. The brake one should have a non-return valve in it. They can be blocked if no spare hose is found in need of attachment. Quote Link to comment Share on other sites More sharing options...
zardos Posted August 22, 2014 Share Posted August 22, 2014 1- Dunno as I megasquirted my engine 2- Correct, can ignore them they are to stop water vapour freezing under certain conditions when the air expands at that point, I plumbed mine in as it was easier than blocking the connection on the rad I was using. 3- I blocked the extra port I had with proper bung which you can buy cheaply from LR suppliers (it has a very old style part number) Quote Link to comment Share on other sites More sharing options...
zardos Posted August 22, 2014 Share Posted August 22, 2014 UpdateRPI say All 14cux have a tune resistor but it might be hidden.http://www.v8engines.com/carbs-2.htm#Tune-resistor Quote Link to comment Share on other sites More sharing options...
mickeyw Posted August 22, 2014 Share Posted August 22, 2014 I used a serp engine of similar vintage and origin. The tune resistor was well hidden, wrapped inside the loom. I removed it (was the catalyst spec white one, and swapped it for the non cat green version). I think the no resistor versions are US market models. There is good info on tune resistors here, also linked to on another thread on here by thecuth Quote Link to comment Share on other sites More sharing options...
aniesigh Posted August 22, 2014 Author Share Posted August 22, 2014 Hmm will have to have a better look for the tune resistor. I did the wiring when the engine was fitted and it's a minimal loom but I may have just wrapped it back up. (It was at least 6 months ago!) And that's confirmed what I thought about the manifold pipes, though the vacuum one was connected but quite possibly not actually, Great cheers all It WILL be done for the de-cider!! (Hopefully) Quote Link to comment Share on other sites More sharing options...
zardos Posted August 22, 2014 Share Posted August 22, 2014 With a multimeter you can detect if the tune resister is present by measuring resistance between pins 5 and 27 on the loom. Quote Link to comment Share on other sites More sharing options...
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