Mk3 Interceptor: This is my 440 EFI conversion log.

[Philip Lochner]

Steve suggested that perhaps the VDO fuel pump I am using is too powerful in the sense that it flows TOO much fuel thus resulting in the fuel in the surge tank being circulated through the engine too often and thus warming up unnecessarily.

This sounded plausible to me, so I fitted another Bosch pump I had which looks identical to the pump from a LR Discovery 2 (which has a fuel pressure regulator rated at 3.5bar), except that it has a gauze filter mounted to the intake of the pump. The new Bosch pump body is literally half the size of the VDO's if that is any measure to go by...

I did not have to remap the engine as the in-line fuel pressure regulator I've had all along is still mounted doing its job, so the fuel rail pressure has not changed.

We now have a heat wave going here with temps well above 30degC so I should know this week still if the heating problem still exists.

[bkbridges]

Philip
With over 45000 miles on 9272s EFI conversion I think I can say it has been a reliable set-up. I don't use a swirl pot, but I do road race, drag race and autocross. Two pumps is one pump too many. A nice Walbro 255lph pump mounted in-line under the car next to the transmission in a spot below the lowest level of the gas tank is the set-up I have run most of the miles with. It is imperative to use a good 100 -200 micron sock on the end of the fuel pick up in the tank (I replaced the Jensen speced unit with a sock from a big block Mopar) and no other pre-filter. A 10 micron filter with a large reservoir (Prestolite EFI filter 1406) after the pump mounted in the right hand front fender well is the only filter I use. The fuel routes through the fuel rails fron the right rear, through a front -8 crossover and out the left rail into the back pressure regulator. Unused fuel is returned to the tank using a 3/8" line. There is some heating of the fuel via the pump and motor heat, but there always will be using a return system. Minimizing connections and complications seems to be working for me! Living and driving in Southern California is definitely a temp and traffic stress test on the car and it has worked fairly flawlessly (other than my pinched crank trigger connector that fell behind the ac compressor...). I cant imagine a pump that is too powerful causing a problem. Ive run my twin Walbro system (for motors over 700hp) on 9272 during its development and there was no problems associated with fuel delivery...
Good Luck!
Bruce

[Philip Lochner]

Did a 187km run yesterday which was actually 3 consecutive 60km runs. At least 1/3rd was still town driving. No fuel heating issues. But...

I now suspect that the noise I was getting from the previous pump was not (directly) heat related but in fact pump cavitation resulting from a partial blockage on the intake to the pump (found when I removed the previous pump). I'm too embarrassed to admit the cause of this blockage but its also possible that warmer fuel might have affected the blockage thus causing the cavitation only to occur when the fuel gets warmer.

With the smaller pump now installed, I can accelerate at full throttle all the way from 0 to 70mph (120km/h / 5000rpm in 2nd) without issues, which I only do to verify that it actually can, (but when it shifts into 3rd something happens which feels like momentary fuel starvation but I need to datalog that situation to be able to investigate what actually happens. I don't see lean conditions on the AFR gauge when this happens, so I doubt its fuel supply related.

[Steve Payne]

Could it be over fueling?

Steve

[Philip Lochner]

Could it be over fueling?

Steve

Unlikely because the AFR gauge is not showing anything untoward...its in the 12- 13 bracket at that time.

[Steve Payne]

I also had a similar problem to this when my transport delay was to short between the injectors and lambda.

Does the ignition map dip into an area where there is a lot less or a lot more advance when it changes gear?

Steve

[Philip Lochner]

When I tune my engines, I use the Lambda to get the fuel map (and all other parameters that affect fuelling) correct to within 3%. This means that I can run the engine completely "open loop" (without a lambda) and still be VERY close to the correct fuelling. If I have a lambda fitted to the car (as I have in the Jensen), I use it only to entertain me and to correct for that last 3% of error. Also, now the engine is not dependent on the lambda even if it should fail.

It can't be advance oddities either since the advance map at WOT is rather flat in the 3000 - 5000rpm area. All is fine up to the shift. The shift is subsecond and after that the engine seems unsure what to do, and then gets going again, in less than, oh, 3 seconds. This why I need to datalog when that happens. Being able to datalog (and view the datalog with Megalogviewer) is one of Megasquirt's other MAJOR selling points.

I'll try and do it this week. Maybe this could serve as a good example of the value of datalogging - if indeed I can find the reason from the datalog.

[Philip Lochner]

(but when it shifts into 3rd something happens which feels like momentary fuel starvation

Turns out I had the dwell (coil charge time) set too low. Coils were not charging sufficiently. Now it pulls strongly all the way to 5500rpm and shifts well into 3rd with power stable.

[Philip Lochner]

Now that I've got everything working to my satisfaction, the fuel consumption figures are in:

http://www.joc.org.uk/phpBB2/viewtopic. ... 21#p160821

[Philip Lochner]

Discovered yesterday that the Throttle Position Sensor on the Edelbrock throttle body was no longer fully operational but was giving inconsistent readings between 0 and 30% throttle. This unit has done much less than 10 000km! It has no markings so presumably is one of the worst quality products ex China.

Whilst not critical for engine operation, it is vital for proper gearbox (GM 4L60e) operation, now installed in my car.

Found that it was the same as being used on small Opel (Vauxhall) utility pickup and bought it locally, on new years eve for about $12, so I promptly bought 2!

[Philip Lochner]

I was invited to a dyno day recently and this is what the dyno measured:

Dyno graph JENSEN GP.jpg (87.15 KiB) Viewed 4504 times

As stated many times before, I place no value whatsoever on the actual values given that this dyno run was done at 1600m (5900') AMSL where barometric pressure is about 84kPA and I have no idea if and when this dyno was calibrated.

What is significant to me is the shape of the graph. Sadly the operators did not follow my instructions and did not do the run from 1000rpm as I had requested. I had programmed the gearbox to stay in 3rd gear (1:1 ratio)at full throttle with the torque convertor locked and wanted to have a run from 1000rpm. It seems this was a stretch too far for those types who have no interest in what happens below 3000rpm.

This graph now sadly only shows what happens from about 1600rpm onwards. Bear in mind that by the time my car does 1600rpm, I am doing 100km/h (64mph). Therefore, my car basically operates between idle and 1600rpm, so this graph tells me NOTHING in the region where it gets used!!!

It does confirm that the 440 is all about torque. To put these figures in perspective: A friend's modified Range Rover Sport 5.0 Supercharged yielded 290kW and 540Nm on the same dyno, immediately before my run was done.

440 Engine spec summary:
Low compression pistons;
Original cam;
Standard exhaust manifolds;
Performer 440 intake manifold;
EFI with Megasquirt-2.

[Steve Payne]

This is what I would expect out of a standard low compression 440. This is about 180hp but as you say the 440 is all about torque.

You have to remember when they were building these engines emission control was in its infancy.

Steve

[jglarkin]

Hi Philip
I completely agree, at 1800rpm I'm way over the speed limit. I find all that high revving business rather tiresome.
I have yet to reset the transmission to make more use of all that torque and reduce the irritation of an early kickdown when accelerating.
The TPS has a big influence on the transmission and have been looking for a more available version to replace the unusual US spec. one I have fitted. Could you tell me the details of the Opel one you have so I could try and get some here.

Thanks

[Philip Lochner]

Could you tell me the details of the Opel one you have so I could try and get some here.

Thanks

This is the unit being used on the Edelbrock throttle body on my car: https://shop.advanceautoparts.com/p/ede ... 22343109-P

When I bought spares locally, I was told they are the same as being used on cars marketed in South Africa as Opel Corsa. They did not give me any more info and I did not think to ask either. I was just too happy to get them on Christmas eve IIRC!!

[Stig]

Interceptor 140-5948 DYNO.pdf.JPG (89.59 KiB) Viewed 4375 times

Can only agree that torque is the key to driving pleasure. After installing an SMR shortie GVO unit I don't get any higher than 2800 rpm even on the motorway - and that correspond to more than the allowed speed (max 120)
The engine was in a dyno (not more than a few meters above sea level) before being installed in the car - so all losses have to be substracted