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Metering head issues.......
#1
Ok!
Just started to change over all the fuelling pack to match up with the stage 2 engine I have installed. To get the car running before eurotec I had reinstalled all the standard DeLorean fuel system.
Anyway I had sent away to be refurbed (KMI) a metering head and matching air regulator, all back OK. From a Volvo 260. Anyway came to start moving everything over today (new injectors Etc Etc) and I have noticed that the Volvo metering head is lacking the outlet (or inlet) for the frequency valve. Not sure which way it flows. There is a dedicated inlet (or outlet) and the return (or feed) goes to the fuel return outlet.
Basically should I return to the stock metering head, or dump the frequency valve . If I dump it (not that I know what it actually does!) do I need to do anything else.
Hope the above all makes some kind of sense. Shock if not I will try to clarify more.
Thanks
Chris
Membership Secretary DOC UK
2021's DeLorean event: http://www.deloreans.co.uk/forum/showthr...p?tid=6056
VIN#15768 Ex VIN#4584
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#2
ahh, right - so that's your metering head! :oops: Big Grin

Apparently the frequency valve is part of the lambda control system. I remember this thread:

http://www.dmctalk.com/showthread.php?t ... =frequency

might be ok just to dump the freq valve. if your fuel distributor doesn't have any accomodation for the freq valve, then I say just leave it off.
there's nowhere else for it to go.
-------------------------
- Dave Smith

VIN: #00944 DOC: #535
VIN: #03193
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#3
yeah, I seem to recall that if you upgrade the engine you dont need the frequency valve any more..........

I'm after a Volvo venturi if anyone's got one - its what I need to finish off my upgrade - big thanks to NickT for letting me loose with his gadgets at Eurotec and all his very helpful advice Smile Hopefully, we might have got to the bottom of one of Flopsy's many niggles...... watch this space !
Claire Wright  - Club Treasurer
Jul 1981 DeLorean - Flopsy #2292 
Aug 1989 Cavalier 1.6L - Guinney
Apr 2021 Mokka-e Launch Edition - Evie
#170
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#4
Quote:Basically should I return to the stock metering head, or dump the frequency valve . If I dump it (not that I know what it actually does!) do I need to do anything else.

Yup, ditch the frequency valve. And pull out your Lambda Computer (extra space in the driver's safe) Your oxygen sensor is then redundant so you can either leave it in, or plug the hole.

Take the vac outlet straight from the manifold to a T piece. One side to the CPR, the other side to the vac advance solenoid.

Set your timing at 10 degrees BTDC

Job done...
Richard H. DOC 365 VIN 1274
http://www.deloreans.co.uk
In theory, theory and practice are the same. In practice, they are not.
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#5
As RichH said ^^^^^^^^^^^^

Also set the CO to 2-2.5% (Volvo) instead of the 1-1.5% CO the original Delorean setup.

As what Claire said, you need the complete ventury with the metering flap etc as the volvo one is larger in diameter.

NickT.
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#6
NickT Wrote:As RichH said ^^^^^^^^^^^^

Also set the CO to 2-2.5% (Volvo) instead of the 1-1.5% CO the original Delorean setup.

As what Claire said, you need the complete ventury with the metering flap etc as the volvo one is larger in diameter.

NickT.

Cheers,
Yes it is complete with the larger ventury (venturi)? I did not realise that was all the computer did. What about the input from the dizzy though does it not upset this not having a computer to talk to?

If this is the case I have just wasted money on some shiney new S/S hoses for the frequency valve Dooh!!!!
Ah well if any one needs the two hoses for the frequency valve brand new in S/Steel from special T auto give me a shout. there yours for what I paid for them, free postage and no import tax.

Chris
Membership Secretary DOC UK
2021's DeLorean event: http://www.deloreans.co.uk/forum/showthr...p?tid=6056
VIN#15768 Ex VIN#4584
Reply
#7
BTW What is the size of the volvo metering flap, does anyone know ??
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#8
There are 3 separate electronic control systems that do not interact with each other at all !

1: Distributor Ignition Amplifier
2: Idle Speed ECU
3: Fuel trim ECU

1: Ignition amplifier just amplifies the signal from the pick up coil in the distributor and switches the nagative side of the coil giving constant dwell for the Spark Ignition

2: Idle speed ecu just controls the idle speed control valve position by electrically switching the outer pins to open/ close the valve. Feedback of the engine speed is done from the negative side of the coil. The coolent temp thermistor in the V coolant pipe under the inlet manifold signals the ecu to give a fast idle when the engine is cold.

3: The fuel computer constantly trims the air to fuel ratio by bleeding off fuel to change the fuel pressure, This is done by changing the duty cycle of the frequency valve (ie the bleed off valve) with feedback from the oxygen sensor. When the engine is cold (lambda switch) or the accelerator is fully pressed down (Wide Open Throttle switch) the duty cycle is fixed to approx 60% for fuel enrichment or 50% if the oxygen sensor is disconnected.

As the 3 computers/circuits do not interact with each other and have thier own control function, this can sometimes result in a cyclic loop and the engine will oscillate up and down once a second (the switching of the oxygen sensor at engine idle). I set the engines up to minimise this of happenning.

The volvo setup is the original design K-Jetronic (not KE-Jetronic - E meaning Electronic control,) doesn't use this fuel ecu and so the metering head doesn't have the second port on the right hand side.

You don't need the fuel ecu so now this can be ebay'd !

NickT.
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#9
NickT Wrote:You don't need the fuel ecu so now this can be ebay'd !

NickT.

or donate the bits to the club as a test pieces for other members to trouble shoot with Smile ... ok well if i dont ask ..... Wink
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#10
bozzzydmc Wrote:BTW What is the size of the volvo metering flap, does anyone know ??

I have them both on the bench at the moment. As near as i can mesure with a micrometer.
The 'stock' DeLorean metering flap is 80mm across

The 'stock' B28E Volvo metering flap is 90mm across.

How this equates to the amount of air I don't know, but I'm sure someone cleverer than me could work it out.

Chris
Membership Secretary DOC UK
2021's DeLorean event: http://www.deloreans.co.uk/forum/showthr...p?tid=6056
VIN#15768 Ex VIN#4584
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#11
when Nick was showing me how to do various tests on Flopsy at Eurotec, we did a graph of what the emissions were at different revs. Going by the graph we got, and the fact that I've got the stock DeLorean venturi, it basically showed that at 3,000 rpm (about 70mph in 5th gear), Flopsy is running at her worst - which could also explain why Phill can smell fuel when he's driving behind me on the motorway but cant at other times or if I am driving behind him. Because the hole in the metering flap is smaller on the De then the Volvo, the car is overfuelling it would seem. I'm sure I've got something wrong here somewhere, so Uncle Nick will be able to explain better if I've cocked it up! :wink:

Anyway, when I've got my car set up the same as Rich's - including the Volvo venturi - it will be interesting to see if I can finally beat him on the drag strip at Santa Pod Big Grin
Claire Wright  - Club Treasurer
Jul 1981 DeLorean - Flopsy #2292 
Aug 1989 Cavalier 1.6L - Guinney
Apr 2021 Mokka-e Launch Edition - Evie
#170
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#12
Claire Usher Wrote:yeah, I seem to recall that if you upgrade the engine you dont need the frequency valve any more..........

I'm after a Volvo venturi if anyone's got one - its what I need to finish off my upgrade - big thanks to NickT for letting me loose with his gadgets at Eurotec and all his very helpful advice Smile Hopefully, we might have got to the bottom of one of Flopsy's many niggles...... watch this space !

Claire, did you try the place on the A1? Thats where I got mine from, though it is easier to call in rather than phone! I can get you the number if you have lost it.
Chris
Membership Secretary DOC UK
2021's DeLorean event: http://www.deloreans.co.uk/forum/showthr...p?tid=6056
VIN#15768 Ex VIN#4584
Reply
#13
Chris & Suzie William Wrote:
bozzzydmc Wrote:BTW What is the size of the volvo metering flap, does anyone know ??

I have them both on the bench at the moment. As near as i can mesure with a micrometer.
The 'stock' DeLorean metering flap is 80mm across

The 'stock' B28E Volvo metering flap is 90mm across.

How this equates to the amount of air I don't know, but I'm sure someone cleverer than me could work it out.

Chris

Cheers for that Chris, good info worth knowing there !
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#14
Quote:Claire, did you try the place on the A1? Thats where I got mine from, though it is easier to call in rather than phone! I can get you the number if you have lost it.
Chris

not exactly local to me anymore mate!! :? Mind you, if you see one next time you're there, give us a bell on the moby and I'll let you know if I still need one (havent had chance to go looking yet) and I'll give you the money for it. We're usually in Stevenage at least once a month to see my mum, so can always come over to Royston and pick it up.

Cheers mate,
Claire Wright  - Club Treasurer
Jul 1981 DeLorean - Flopsy #2292 
Aug 1989 Cavalier 1.6L - Guinney
Apr 2021 Mokka-e Launch Edition - Evie
#170
Reply
#15
No prob, will do

Chris
Membership Secretary DOC UK
2021's DeLorean event: http://www.deloreans.co.uk/forum/showthr...p?tid=6056
VIN#15768 Ex VIN#4584
Reply


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