Mk 3 Interceptor 1974

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johnw
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Re: Mk 3 Interceptor 1974

Post by johnw »

Pop the distributor cover, rotate the engine one way then the other. You are looking for the amount of slack rotation degrees until the rotor arm moves. It shouldn't be a lot. Compare it to your other Jensens. Swapping the chain on a Mk1 is an afternoon job. On the Mk3 you have the aircon pump to move and less room. This won't tell you if the chain has jumped, but the presence of slack means it could have.
Have you seen our stolen Jensen FF 119/011 https://twitter.com/jensenffdotcom
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Re: Mk 3 Interceptor 1974

Post by KaranMK2 »

Thanks John. I will give that a go soon. Grant, I did pour some fuel in as you suggested but no joy. Tell you what I did notice - the electric fuel pump keeps ticking and after a while there is a continuous trickle of petrol in the two front throats of the carb. I kind of expected it to stop after priming as the continuous trickle is just flood the engine right? Karan
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johnw
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Re: Mk 3 Interceptor 1974

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KaranMK2 wrote: Tue Jul 13, 2021 6:36 pm Thanks John. I will give that a go soon. Grant, I did pour some fuel in as you suggested but no joy. Tell you what I did notice - the electric fuel pump keeps ticking and after a while there is a continuous trickle of petrol in the two front throats of the carb. I kind of expected it to stop after priming as the continuous trickle is just flood the engine right? Karan
That fuel trickle is obviously a bit dangerous as you could hydrolock the engine and crack the block or head if you left the ignition on for too long and the cylinder runners filled up with fuel then you tried to start it. The problem could be that the pressure from the fuel pump is too much for the floats to hold back. There is a pressure regulator with electric pump conversions either in the pump or externally apparently (I have only ever had the mechanical pumps). I don't think your starting problems are directly related to this trickle, as this is a bit like doing what Grant suggested pouring in the fuel.
Have you seen our stolen Jensen FF 119/011 https://twitter.com/jensenffdotcom
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Grant
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Re: Mk 3 Interceptor 1974

Post by Grant »

KaranMK2 wrote: Tue Jul 13, 2021 6:36 pm Thanks John. I will give that a go soon. Grant, I did pour some fuel in as you suggested but no joy. Tell you what I did notice - the electric fuel pump keeps ticking and after a while there is a continuous trickle of petrol in the two front throats of the carb. I kind of expected it to stop after priming as the continuous trickle is just flood the engine right? Karan
Yes correct, flooding, therefore the float valve in the carb is letting by Karan, it would also explain the backfire if it is flooding, I think you have carb issues there Karan, you could if you don't want to change the carb yet and to check it is the carb, disconnect the fuel pump and try it then,, it sounds flooded yes, once some of the fuel has gone down it may run ok untill the carb empties :wink: ..well done for noticing that Karan :wink:
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KaranMK2
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Re: Mk 3 Interceptor 1974

Post by KaranMK2 »

Good suggestion Grant. I will get back to that in a few days time and report back. Got tied up on installing a 123 distributor / electronic system on the M10 - 4 cylinder engine of my ‘68 bmw 2000ca.
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Re: Mk 3 Interceptor 1974

Post by KaranMK2 »

Update: Thanks for the assistance. I think it is the timing chain as I did as John suggested and the slack is considerable at almost 30 degrees of turn before any movement of the rotor arm. I adjusted the distributor to compensate and it fire up and ran but not really all that great. So, I will now source parts as necessary and replace including the starter solenoid that got extremely hot from the constant attempts at starting. I also found that the cable from the starter solenoid to the starter motor was bare of it’s insulation at one place. Guess at some point it got too close to the exhaust manifold.

Kr
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rta50car
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Re: Mk 3 Interceptor 1974

Post by rta50car »

Karan - You may have stuck floats in the float chambers. I dont see a sight glass each end to help you gauge interior float level. If any float is stuck with fuel inlet open you are going to have massive flooding. Maybe put plenty of old rags below carby area and undo fuel lines at each end and disassemble each end and check. May be the cause if car has not been used for a while.
1969 Mk 1 Jensen Interceptor Chassis number 115/3227
1951 FX Holden
KaranMK2
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Re: Mk 3 Interceptor 1974

Post by KaranMK2 »

Thanks RTA50CAR - i will take a look at that. I am in the middle of changing the timing belt.I now need to get a puller to take off the final pulley from the crank shaft - darn thing is stuck firm and there is very little room to work plus I am hesitant to take to out the radiator.

John, you did very well to do it so quickly.

Kind regards,
Karan
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johnw
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Re: Mk 3 Interceptor 1974

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I made a puller from a single piece of thick wall square section 13mm steel tube, with a hole drilled at both ends to line up with the pulley mounting holes. I then tighten the tube down on the crank centre bolt which has been suitably loosened first. The trick is to find 2 threaded rods that go all the way through the damper pulley mounts, but not sticking out to avoid fowling the engine. Nuts can then be use to draw off the damper. Suitably long bolts with washers can be used instead but make sure the full thread depth of the pulley is engaged. To avoid damaging the crank bolt, you can remove it and use a socket or similar as a spacer to bear down on. You might want to paint the water pump housing and front engine cover while they are off. That really smartens the engine up.
Have you seen our stolen Jensen FF 119/011 https://twitter.com/jensenffdotcom
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Re: Mk 3 Interceptor 1974

Post by KaranMK2 »

Thanks John. I made a bracket up like you have suggested but the gauge of steel that I used was not thick enough so it bent as I used it. I will wait on the pulley that I have ordered as it will use the three bolt holes rather than two. Yes, sorting out the water pump housing, fan motors and radiator cowling is best done now along with all mess at the bottom that you usually can’t get to.
Kind regards,
Karan
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Re: Mk 3 Interceptor 1974

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Proper puller used today to remove the pulley and then I removed the cover to get to the timing chain. The two bolts underneath the cover were a bit tricky to undo as there is not much room to work due to cross frame and steering rack that are in the same area. Anyway, found far too much slack on the timing chain and a few broken tooth found.
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johnw
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Re: Mk 3 Interceptor 1974

Post by johnw »

I think that is the starting problem plus backfires.
You really need to pull the sump and remove the broken teeth in the sump. Also you can do a better job of the sump gasket when the timing cover goes on before the sump.

As Rocky said you have a problem with the fuel drips from the primaries! That could be too much pressure from the electric pump if it is the wrong type.

This is the nightmare timing chain scenario on a Jensen as bad as it gets thankfully. If the oil pickup strainer is still fitted that should have saved the day. No need for a new engine etc. Just a good clean.

As this 50 year old plastic gear rotted over the years people fitted electric fuel pumps and upgraded ignition to get it to start before things got really bad. At least you can have confidence in the low mileage!
Have you seen our stolen Jensen FF 119/011 https://twitter.com/jensenffdotcom
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Re: Mk 3 Interceptor 1974

Post by KaranMK2 »

Thanks John . I will see what is in the sump. I will also pick up on Rocky’s suggestion. Please can you tell me where the oil pick up strainer is located. Wonder why Chrysler thought it was a good idea to put plastic on this important gear!!! In time, I will check the timing gears on my other interceptors to see if they have ones with plastics teeth cover still fitted and change if that’s the case.
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Grant
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Re: Mk 3 Interceptor 1974

Post by Grant »

Slotcarone was correct then KaranImage...it was a timing chain issue,well done that manImage..the strainer is on the end of the oil pick-up pipe Karan..in the sump :wink:
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Re: Mk 3 Interceptor 1974

Post by KaranMK2 »

Everyone on this post helped me out on this issue Grant. Hopefully when I put it all back together it will be ok. Now that I have room to access a few things in that area, I have decided on a clean up / tidy up job before reassembly so that tomorrow’s Job. The car is on Jacks so next week I will take a look at the sump. Even tempted to install a fast starter that I acquired. John, the electric fuel pump was installed by a PO and the car ran with it for many years until I bought so I guess the pressure is ok but it’s very noisy. I will post some photos of that installation in due course. Prior to Jensen ownership, I would not even contemplate the auto stuff that I now do as a hobby.

Kind regards,

Karan
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