Defender 90 V8 running rich i think?

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Becks Bear

Becks Bear

Active Member
Posts
245
Location
Northern Ireland
My Defender V8 appears to be running rich, based on my very limited knowledge of V8s.

The old girl gets well looked after however I can smell petrol fumes at the exhaust, it’s not the most definitive way of telling if she’s running rich. I am trying to find someone who lives near me that can actually works or can carry out diagnostics on the old girl but as yet I can’t find anyone with the experience required.

So based on its running rich what should I be looking for or at????

Please try and keep it simple for me……………………..cheers Ivan
 
Black plugs. I'd change the plugs and see what they look like after a few hundred miles. The colour should tell you a fair bit and go from there. What spec is it - carbs, injected, flapper, stepper ,ECU?
 
Sorry, didn't seem to go first time around so sent again, hence the double post. Can't find a delete option.
 
4.2 short engine which has been built up to be a 282 bhp engine.

The heads are V8 Developments stage 3 big valve heads and sit on composite head gaskets, and a standard 3.9EFI camshaft.

The exhaust manifolds are standard 3.9 EFI Range Rover, but have been machined to match the exhaust ports on the head and as such have TVR big bore gaskets fitted, and a stainless steel 63mm exhaust from the down pipe connection to the rear with only one silencer.

NGK BPR6ES spark plugs just fitted 1000 miles +/- ago

The engine is fitted with Hotwire EFI and was originally set up on the rolling road by Mark Adams.

The distributor is (35DLM8) along with Magnecour leads and Lucas remote amplifier.

Complete full service in July just before I drove the NC 500.

New genuine dizzy and genuine rotor arm fitted a few months back before July.

Oil and large oil filter changed every 3000 miles whether she likes it or not she gets it changed, complete with whatever she needs.

New stepper motor fitted maybe in Feb this year.

MAF looks absolutely shining inside and inspected around July.

Fitted with K&N air filter; however when I was cleaning/looking at the MAF in July the air filter did appear dirty, the air intake is connected to a Mantec V8 snorkel, no holes in the air supply hose, blew the air filter with the air compressor and refitted.

Vehicle Speed sensor has had to be bypassed as the small cable broke, so I just fitted a direct speedo cable from the speedo clock to the transfer box as a temporary fix, as I intend changing the dash to TD5 etc etc etc and will wire in the TD5 transducer to the ECU with a signal wire.

As I said I have recently just started to smell the petrol fumes from the exhaust, it doesn’t stall, it pulls like a train, plenty of torque???????????????????
 
4.2 short engine which has been built up to be a 282 bhp engine.

The heads are V8 Developments stage 3 big valve heads and sit on composite head gaskets, and a standard 3.9EFI camshaft.

The exhaust manifolds are standard 3.9 EFI Range Rover, but have been machined to match the exhaust ports on the head and as such have TVR big bore gaskets fitted, and a stainless steel 63mm exhaust from the down pipe connection to the rear with only one silencer.

NGK BPR6ES spark plugs just fitted 1000 miles +/- ago

The engine is fitted with Hotwire EFI and was originally set up on the rolling road by Mark Adams.

The distributor is (35DLM8) along with Magnecour leads and Lucas remote amplifier.

Complete full service in July just before I drove the NC 500.

New genuine dizzy and genuine rotor arm fitted a few months back before July.

Oil and large oil filter changed every 3000 miles whether she likes it or not she gets it changed, complete with whatever she needs.

New stepper motor fitted maybe in Feb this year.

MAF looks absolutely shining inside and inspected around July.

Fitted with K&N air filter; however when I was cleaning/looking at the MAF in July the air filter did appear dirty, the air intake is connected to a Mantec V8 snorkel, no holes in the air supply hose, blew the air filter with the air compressor and refitted.

Vehicle Speed sensor has had to be bypassed as the small cable broke, so I just fitted a direct speedo cable from the speedo clock to the transfer box as a temporary fix, as I intend changing the dash to TD5 etc etc etc and will wire in the TD5 transducer to the ECU with a signal wire.

As I said I have recently just started to smell the petrol fumes from the exhaust, it doesn’t stall, it pulls like a train, plenty of torque???????????????????
 
Sounds a similar set up to my TVR engine, which is a 4.3. Is it still on the Lucas 14CUX? Have you checked the plug colour (BPR6ES is a good choice). If its pulling well its going to be a difficult one to solve - always better when something fails.
 
Becks Bear said:
yes going to have a good investigation when i get home next week, will pull the plugs but 1000 miles isn't long for a set to go bad.
Click to expand...
Wasn't saying the plugs had gone bad but just wondered what colour they were. You say its running rich but is it really. My TVR did and I had to run out the garage when I reversed it in as the stink was incredible. Now not rich but still splatters anything behind on start up.
 
No problem. Should give you a good indication of how the engine is running. Also try to pull all 8 so you can see if 1 or more is a different colour which then may prompt further investigation. K&N do a clean and oil kit - did you oil the K&N before fitting, although some are pre oiled? https://www.carparts4less.co.uk/cp4...MIhcCG6abE3gIVirHtCh1FLgdYEAQYAiABEgIfEfD_BwE. K&N state do not use an air compressor to clean them as it rips the fibres in the filter - extract from K&N site:
12. Can I use compressed air to dry the filter faster?
Never use compressed air to dry your air filter. Compressed air will rip and tear the fibers that make up the filtering material. Always allow the filter to dry naturally.
FFG
 
You say running rich? Have you had it on a gas analyser? Anyway, sounds like quite an engine so it should be a simple problem. I suspect the issue might be the loss of the speed transducer, this may have caused a fault condition with the ecu so it has defaulted to limp mode which is a basic rich fuel map. Best thing to do is plug the ecu in to a code reader and see what, if any, faults are stored.
 
classic kev said:
You say running rich? Have you had it on a gas analyser? Anyway, sounds like quite an engine so it should be a simple problem. I suspect the issue might be the loss of the speed transducer, this may have caused a fault condition with the ecu so it has defaulted to limp mode which is a basic rich fuel map. Best thing to do is plug the ecu in to a code reader and see what, if any, faults are stored.
Click to expand...
kev
plugged her into rovergauge and the only fault was the speed sensor which i knew would appear no other faults showed up on the diagnostics, cleared and took her for a spin no issues however the speed sensor came back as expected.
no worries as i am planning to fit a TD5 speedo and then run a signal wire to the ECU, will see how this runs

i am beginning to think that shes not running rich, will plug the plugs and have a look when i get time..........................cheers ivan
 
:D:D:D:D:D

Close, it is the other one :p PM came through. All is good here, hope so with you all too.

M
 
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