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cosecon

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Posts posted by cosecon

    RV8 Under-Bonnet Pics

    in Defender Forum (1983 - 2016)

    Posted

    Eh ?? Ported ??

    "MANIFOLD VACUUM

    Is obtained from a passage under the throttle blade. Manifold vacuum vacuum is high ( 15-18 in Hg) when the engine is idling and decreases as the throttle is opened. At wide open throttle ( loaded) manifold vacuum is considered to be a zero.

    PORTED VACUUM

    Is obtained from a passage just above the closed throttle. At idle, no vacuum is applied this port due to its location. As the throttle is opened, this port is exposed to manifold vacuum, so vacuum at this port begins to increase. Since ported vacuum is actually manifold vacuum applied to a different passage it will also be near zero when wide open throttle. "

    reference to: http://www.emsgas.co...ges/vacuum1.htm

    vacuum1.gif

    v8 4.0 14cux rougth idle and shacky low rpm

    in International Forum

    Posted

    After checking all, I reached the conclusion of faulty Air Flow meters. I tried a 3rd one from a friend and I had much better and smoother operation than before.

    I also found out that when my 2 AFMs are cold (not the engine, just newly installed afm on a warm engine) it is working nicely. Once the afm heats up....it looses accurate performance....

    I guess I will accelerate the megasquirt installation. I am not worried about cabling...I am worried about fuel maps (spark maps I already have...)

    I guess if I am stuck I can always send air tickets to a "Grown Up" for a free weekend in Greece....

    v8 4.0 14cux rougth idle and shacky low rpm

    in International Forum

    Posted

    Silly question but have you cleaned / gapped the plugs or tried new?

    Have you systematically replaced HT leads to see if one failing to deliver a spark (Would notice it far more at low RPM)

    Spark plugs brand new, changed 500miles ago

    HT leads Brand new (installation of megajolt)

    No-one has mentioned it, so have you tried measuring the voltages coming out of the MAF? The low rpm mixture on the MAF is adjustable, pretty much like the idle mixture screw on a carb. Theoretically you need a CO meter but you can do it by ear using the lean drop method. There is plenty of info on the web about how to do this and which wires to measure. 45 Kpa is a bit high but within limits. 13 BTDC is OK with a megajolt, imho. You can even go higher.

    CO adjusted on a high tech analyzer. AFM values are a little less than expected. 1.45 volt in idle instead of 1.6 idle. Tested a second used ebay afm and similar values.

    I suspect vacuum leak (45Kpa looks a bit to the high side) but not possible to find .... I tried spraying carb cleaner even on the injector holes on the manifold but no leak...

    v8 4.0 14cux rougth idle and shacky low rpm

    in International Forum

    Posted

    On the face of it I'd say you're advance is a bit high for idle and that may be contributing to the problem. Have you checked the advance with a timing light and ensured the timing marks are correct ?

    I have confirmed TDC marks and my vr sensor is less than half a degree out. I have tried several different advance settings, including 8, 10, 12 degrees with no luck, that is why I sort of ruled out ignition.

    Just to rule it out as a source of problems, warm the engine up and while it's idling disconnect the 4 way plug from the idle air control stepper on the RHS of the plenum. See if that makes any difference to the stability of the idle and also to the low rpm cruise problem.

    I will test this, although I doubt it since I have also tried a spare Idle air control stepper.

    It is not that I have a bad idle, it is ok but just not perfect.

    I just had another thought... I checked for vacuum leaks everywhere....except injector o-ring to manifold....What if I have some leak at any of the injectors?

    v8 4.0 14cux rougth idle and shacky low rpm

    in International Forum

    Posted

    Hi to all

    I have a Defender 90 manual fitted with a cross bolted V8 4.0L. The cylinder heads are original 3.5 carb, but skimmed accordingly for composite gasket fitting. The heads are quite extensively ported. I currently have hotwire EFI installed and Megajolt.

    My engine performs very nicely in all rev range. I have a 2 small but annoying problems, which I had with the distributor also:

    1. On idle, I have normal 700rpms with a small variation of +-25 rpm, but it feels a bit shaky. (rough). It is like when I had carbs and the choke was applied in a warm up engine, but no black smoke and emission testing in idle is ok. My advance in idle stationary is 13 BTDC and engine load (vacuum is 45Kpa). Yesterday I readjusted the base idle as per manual and I was able to go down to 480 rpm with the engine not stalling. I readjusted up to 525+-25 as per manual
    2. When cruising with 1000-1500 rpm, with the foot just touching the throttle, you get this shaky feeling. If you just press a little more the accelerator, It is perfect running.

    My belief is that both problems are related.

    So far I have tried:
    1. to replace with spare Throttle pot
    2. to replace with spare Idle valve
    3. to replace with spare AFM (but both I have are not “known to be working”, they were bought on EBAY)
    4. to decrease fuel pressure (I have and adjustable regulator) things got worse.
    5. Connected several time to ecu fault reader with no faults.

    I would like to inform you that I have a speed transducer connected, I have a manual box and no oxygen sensor with proper tune resistor. Before , i had a webber 4barel with lucas distributor with no such problem.

    Is it possible that the K&N cone filter I have directly connected to the AFM is “confusing “ the air flow meter with pulse air in low load/rpm?

    What do you believe I should check?

    Thanks

    P.S. I know the answer is megasquirt, but I would like to postpone a few months for "funding" of MS

    Defender v8 carb to v8 14cux Success.Photos and 1 question.

    in Defender Forum (1983 - 2016)

    Posted

    Last weekend I finally installed megajolt and edis. I know it is not the best option to keep 14cux hotwire and add megajolt and that Megasquirt would be the way to go, but I decided one small step at a time.

    I had 2 problems during my installation which I would like to share with everybody.

    1. I made the vr sensor wiring exactly as in the manual, but it would not start. As soon as I inverted the 2 wires it worked.
    2. My engine would not switch off. In my installation in order to provide the megajolt, edis and coilpacks with swiched positive, I got one line straight from the battery (with a fuse of course) and swiched it with a simple relay using the swichable positive from the 14cuxhotwire. It would not switch of. I used a diode in the switched positive just before the relay and it works (I remember reading some advise from HFH if I am not mistaken, but referred to Megasquirt).

    I think spark is an even better mod than fuel…

    The engine is smooth in all rpm and it is revving up to 5800rpm (rev limit setting) without any hesitation.

    I installed the coils on the rear of the engine between engine and bulkhead. I will post some photos in the next few days.

    3.9 EFI not injecting

    in Range Rover Forum

    Posted

    The hotwire 14cux, when you turn the key to ignition, without cranking, the fuel pump should be energised for a couple of secs and then switches of. It get alive again when rpm signal is sent from -ve from the coil to the ecu (cranking or running).

    I would also check the pump inhibit switch (fitted to rrc) . One other important isue is the relays. The relays are not simple relays, but they have a small diode inline (not parallel to the coil). I have observed that with out the diode on the main relay, my engine will not switch off, so maybe this is your case in fuel pump.

    See relay schematic bellow.

    AFU2913A.jpg

    Clutch master cylinder

    in Defender Forum (1983 - 2016)

    Posted

    I used to have problems with mine, every 20.000 miles. I tried 2 new genuine ones, same result, I tried a repair set from Lucas, same result. I finally dismantled it and went to a small local brake workshop and I found some compatible seals from a Toyota...never had any problem since and it is mote than 35.000miles ago.

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