Over cooling on a rover v8

Discopotatoes · Post by **Discopotatoes** » Fri Jun 15, 2012 5:15 pm

Hi all,
I have recently taken my maiden voyage in twin turbo Tvr chimaera and oddly found it to be over cooling on a run but temps creep up to 85 deg around town when giving it beans, completely the opposite of what I expected because I have a dirty great inter cooler directly in front of the rad and only one 12" pull fan instead of two due to space constraints,which kicks in at 90 and off at 85.
I also have a large oil cooler with high flow stat installed again in front of the inter cooler .
I checked the 82deg thermo and it was found to be working, but changed it for an 88 deg( yet to be tested).
I have been told that the gauge could be reading wrong, but the plugs are fouling, and also that the standard gauge sender sticking out of the front of the manifold is not the best place for it and rather to use the the one on the top further back.
Any thoughts appreciated
Cheers

stevieturbo · Post by **stevieturbo** » Fri Jun 15, 2012 6:26 pm

85degC would still be deemed cool

If it's overcooling, then maybe the thermostat isnt sealing properly, or the system isnt plumbed just right.

Above 25-30mph, fans do nothing anyway.

OEM gauges are rarely accurate. They are just a guide to temperature. Fix that laptop and see what temp the ecu is reading.

Plugs fouling can be many things

Plug too cold heat range
Excessive fuelling
Poor ignition system

A cold engine ( and yours is not cold ) is not a reason for fouling the plugs.

Temp sensor should ideally be close to the thermostat on the hot side.

SimpleSimon · Post by **SimpleSimon** » Fri Jun 15, 2012 7:25 pm

Don't trust the stock TVR temp
gauge

Discopotatoes · Post by **Discopotatoes** » Fri Jun 15, 2012 9:01 pm

stevieturbo wrote:85degC would still be deemed cool

If it's overcooling, then maybe the thermostat isnt sealing properly, or the system isnt plumbed just right.

Above 25-30mph, fans do nothing anyway.

OEM gauges are rarely accurate. They are just a guide to temperature. Fix that laptop and see what temp the ecu is reading.

Plugs fouling can be many things

Plug too cold heat range
Excessive fuelling
Poor ignition system

A cold engine ( and yours is not cold ) is not a reason for fouling the plugs.

Temp sensor should ideally be close to the thermostat on the hot side.

I was advised by the mapper to put ngk shrouded 8s in but the protruding 7s looked the same so I guess excessive fuelling, we had a misfire on the dyno again I'm guessing due to to much fuel and fouled plugs. I have a healthy spark and good even compression across all 8 cylinders
The laptop is first on the list when I get back from work,

Discopotatoes · Post by **Discopotatoes** » Fri Jun 15, 2012 9:03 pm

SimpleSimon wrote:Don't trust the stock TVR temp
gauge

I don't but I'm going to move the sender and get a resistor in the wire to get it to read accurately

stevieturbo · Post by **stevieturbo** » Fri Jun 15, 2012 9:11 pm

Discopotatoes wrote: I was advised by the mapper to put ngk shrouded 8s in but the protruding 7s looked the same so I guess excessive fuelling, we had a misfire on the dyno again I'm guessing due to to much fuel and fouled plugs. I have a healthy spark and good even compression across all 8 cylinders
The laptop is first on the list when I get back from work,

Well then if it is excessive fuelling, ask your mapper why he is doing that. It's his job to ensure that doesnt happen

7's or 8's would be ok...but I'd probably stick with 7's unless you have a powerful ignition system.

Missfire could be an indication of poor ignition system, or many other factors. It could be excessive fuel too...but then that shouldnt be happening when mapping on the dyno in the first place.

Exactly what is the makeup of your ignition system ? and how are you determining that spark is good ? ( given you should not be over fuelling, and you do have fouled plugs and misfires )

Discopotatoes · Post by **Discopotatoes** » Fri Jun 15, 2012 9:28 pm

stevieturbo wrote:
Discopotatoes wrote: I was advised by the mapper to put ngk shrouded 8s in but the protruding 7s looked the same so I guess excessive fuelling, we had a misfire on the dyno again I'm guessing due to to much fuel and fouled plugs. I have a healthy spark and good even compression across all 8 cylinders
The laptop is first on the list when I get back from work,
Well then if it is excessive fuelling, ask your mapper why he is doing that. It's his job to ensure that doesnt happen

7's or 8's would be ok...but I'd probably stick with 7's unless you have a powerful ignition system.

Missfire could be an indication of poor ignition system, or many other factors. It could be excessive fuel too...but then that shouldnt be happening when mapping on the dyno in the first place.I

Exactly what is the makeup of your ignition system ? and how are you determining that spark is good ? ( given you should not be over fuelling, and you do have fouled plugs and misfires )

Wasted spark, Ford gen 1 coil packs 8mm silicone leads and ngk BCR8ES gapped to 0.028, I have checked the spark at each plug so the leads look good, also pulled the coil end of the leads off one at a time and the spark will jump about 20mm so coils both good, thought I had better add the injectors are 650 cc rc racing if that would make a diference to the fueling

stevieturbo · Post by **stevieturbo** » Fri Jun 15, 2012 9:44 pm

20mm should be ok.

No idea what Gen1 ford coils are though.

But most modern 4 tower coils are pretty decent, I'll assume thats the type of thing you are referring to.

Injector size wont matter, the ecu will be mapped to suit. Or at least it should be.

Sounds like your mapper needs to answer a few questions. You shouldnt be fouling plugs, misfiring or any of those issues if it is mapped properly.

jan_rrc39v8 · Post by **jan_rrc39v8** » Sat Jun 16, 2012 6:46 pm

stevieturbo wrote: Sounds like your mapper needs to answer a few questions. You shouldnt be fouling plugs, misfiring or any of those issues if it is mapped properly.

maybe the fuel pressure regulator is broken? When the membrane inside is torn the pressure on the injectors will no longer be controlled and the full linepressure will be on the injectors at all times.
If a vacume line is connected to the FPR this can also act as a leakidge channel through which leaked fuel can get into the manifold in a totally uncontrolled way (meaning not through timed injection pulses.

The end effect of a leaking FPR is likely to be UBER-rich mixture...
(and the initial mapper is off the hook)

stevieturbo · Post by **stevieturbo** » Sat Jun 16, 2012 6:51 pm

jan_rrc39v8 wrote:
stevieturbo wrote: Sounds like your mapper needs to answer a few questions. You shouldnt be fouling plugs, misfiring or any of those issues if it is mapped properly.
maybe the fuel pressure regulator is broken? When the membrane inside is torn the pressure on the injectors will no longer be controlled and the full linepressure will be on the injectors at all times.
If a vacume line is connected to the FPR this can also act as a leakidge channel through which leaked fuel can get into the manifold in a totally uncontrolled way (meaning not through timed injection pulses.

The end effect of a leaking FPR is likely to be UBER-rich mixture...
(and the initial mapper is off the hook)

Possible, but a very very rare scenario. Certainly one Ive never seen or heard of happening.

But it seems these issues were apparent when the vehicle was being mapped ? So there should have been some answers at that time.

jan_rrc39v8 · Post by **jan_rrc39v8** » Mon Jun 18, 2012 6:58 pm

i have seen it a few times on older Volvo's and BMW's. Bosch parts, very similar to the FPR on a RRC V8 EFi system.
It happens. But it's very easy to check: start engine, pull the vac line, see if fuel squirts out, in doubt smell for fuel coming out. If YES, replace it.

SimpleSimon · Post by **SimpleSimon** » Wed Jul 11, 2012 1:34 pm

Discopotatoes wrote:
stevieturbo wrote:
Discopotatoes wrote: I was advised by the mapper to put ngk shrouded 8s in but the protruding 7s looked the same so I guess excessive fuelling, we had a misfire on the dyno again I'm guessing due to to much fuel and fouled plugs. I have a healthy spark and good even compression across all 8 cylinders
The laptop is first on the list when I get back from work,
Well then if it is excessive fuelling, ask your mapper why he is doing that. It's his job to ensure that doesnt happen

7's or 8's would be ok...but I'd probably stick with 7's unless you have a powerful ignition system.

Missfire could be an indication of poor ignition system, or many other factors. It could be excessive fuel too...but then that shouldnt be happening when mapping on the dyno in the first place.I

Exactly what is the makeup of your ignition system ? and how are you determining that spark is good ? ( given you should not be over fuelling, and you do have fouled plugs and misfires )
Wasted spark, Ford gen 1 coil packs 8mm silicone leads and ngk BCR8ES gapped to 0.028, I have checked the spark at each plug so the leads look good, also pulled the coil end of the leads off one at a time and the spark will jump about 20mm so coils both good, thought I had better add the injectors are 650 cc rc racing if that would make a diference to the fueling

Not quite sure why your running such small spark gaps with W/Spark ign 34/40thou should be more like it, what engine ECU you running? StevieTurbo you are correct in assuming Gen 1 coils are 4 tower coils & very common on earlier Fords and insanely reliable

and the only way you could destroy one of these is if you had an incorrect switching duration in the ECU

Discopotatoes · Post by **Discopotatoes** » Wed Jul 11, 2012 5:06 pm

SimpleSimon wrote:
Discopotatoes wrote:
stevieturbo wrote:
Discopotatoes wrote: I was advised by the mapper to put ngk shrouded 8s in but the protruding 7s looked the same so I guess excessive fuelling, we had a misfire on the dyno again I'm guessing due to to much fuel and fouled plugs. I have a healthy spark and good even compression across all 8 cylinders
The laptop is first on the list when I get back from work,
Well then if it is excessive fuelling, ask your mapper why he is doing that. It's his job to ensure that doesnt happen

7's or 8's would be ok...but I'd probably stick with 7's unless you have a powerful ignition system.

Missfire could be an indication of poor ignition system, or many other factors. It could be excessive fuel too...but then that shouldnt be happening when mapping on the dyno in the first place.I

Exactly what is the makeup of your ignition system ? and how are you determining that spark is good ? ( given you should not be over fuelling, and you do have fouled plugs and misfires )
Wasted spark, Ford gen 1 coil packs 8mm silicone leads and ngk BCR8ES gapped to 0.028, I have checked the spark at each plug so the leads look good, also pulled the coil end of the leads off one at a time and the spark will jump about 20mm so coils both good, thought I had better add the injectors are 650 cc rc racing if that would make a diference to the fueling
Not quite sure why your running such small spark gaps with W/Spark ign 34/40thou should be more like it, what engine ECU you running? StevieTurbo you are correct in assuming Gen 1 coils are 4 tower coils & very common on earlier Fords and insanely reliable and the only way you could destroy one of these is if you had an incorrect switching duration in the ECU

I was told so set the gaps at 0.028 by Steve Greenauld from track an road tuning also to use shrouded 8s. I have been told by a number of other people that I should be running non shrouded 7s gapped at 40 thou, it would be nice if someone could explain why they quote the plug and gap that they do, as it all seems a bit hit and miss.

stevieturbo · Post by **stevieturbo** » Wed Jul 11, 2012 8:51 pm

There are no downsides whatsoever to running a 28 thou gap compared to a 40 thou gap.

That is not an issue whatsoever.