1.7 Warm Start Issues

[Chris_C]

I have a problem

Basically, in the last week or so (mainly since I fitted a new starter, but I reckon that conincidence) Fake has been not wanting to startl when warm. Everytime, look at the plugs, and they are black, so cleaned, and off we go. Andy said to check dizzy, which I'd been putting off as it's the 1.7, but after two screws and the heater fan off, easy job. Corroded to anything, so cleaned the arm, and the contacts, and all is well.

Anyway, couple of days later, does it again (some how cleaning dizzys never works for long) so new dizzy, check plugs, and they are now orangey, not black, on the ceramic bits, and black on the electrodes. Ok, new plugs with new dizzy cap and arm.

Today... 20 miles later. Won't start. Electrodes black. Still. Not chuffed. Left tools at home thinking I'd sorted the problem.

Luckily, have socket set, and find piece of cardboard to get soot off plugs.

Ok, here is what I reckon:

*Earth lead not making good contact, I'm going to sort that with some heat and solder now.
*Choke cable not adjusted proper, I'll try and sort that, but see below
*Fake has the replacement weber carb. I can't find a mixture screw on it, it has an idle, but I can't see what would be a co2. Turns out the one I thought was, doesn't change naff all.

Now, cos this is a weber, there is nothing about it in the haynes or russek manuals, so I'm going to try doing the choke cable as per the solex setup, and hope. I'm also going to check to see if it's the same as the 1.4 one, as that doesn't have a co2 adjust either. There are also 2 wires cable tied up next to the carb, I'm guess idle solanoid and something? Didn't check, was a quick look to see, but blue/red or blue yellow I think.

Any better ideas guys on what else it could be or how to set up the weber?

Cheers

(sorry my problem posts always go on for ever, but I try and put what may be useful, even thought half of it probably isn't )

[340GLT]

The 1.4 Weber does have a mixture screw mate! Its at the base of carb in front of you if you look from passenger side wing. Whereas the idle adjust is in the same direction but towards the back of the carb.
As for warm starting mine has this problem and i know its the diaphragm so need to get that sorted.
Adam

[Chris_C]

I thought I'd found one on Kar before.. I must having been mis reading Haynes! it's in a tubey bit on the casting no? hmm, arse, looking at the diagram again they are definately different, might go and take some pics, someone might be able to point out a mixture screw.

[Chris_C]

Hmm, ok, after trying to consult Haynes diagnose a spark plug page, I looked in Russek, seemingly the plugs I have got (sooted electrode, but grey/red ish ceramic bit) are the right colour. The other day on dodgy dizzy the white bit was black too.

So, new leads are here, and I will go out and have a play with choke flap, and see if I can fiddle the choke stops. Idle is good, and I've found out the solex hides it's CO2 adjustment, so I'll see if the weber equiv does. It's definately not a 1.4 carb anyway, it has the top down idle adjustment of the solex, unlike the 1.4 one.

[foggyjames]

Does anything you do to the carb (choke, WOT, etc) aid or alter starting at all? If not, I'd start looking at ignition. Run the checks in Haynes on the Renix unit. Bloody French engineering.... which is proving better than the Swedish stuff at present

cheers

James

[Chris_C]

Just finished a couple of lazy mucking round with the ignition. Flywheel sensor off, 5mm of crap cleaned from it. Renix out, (had pulled another one from a late '89 yesterday too) and found they were different, seemingly not only was the coil contacts in Fakes renix corroded, it was the wrong one (85 1.7, so seemingly a couple of degrees retarded or advantaced, I reckon retarded, as that entire engine is flippin' retarded, but hey)

Erm, checked choke, was fine, and anyway, it's started on the key everytime today (been going out ever 30mins to 120mins, give it some variety) and all seems better, but gonna do the same again tomorrow.

Worked out fuel consumption had gone done to 25mpg in the last fortnight, thats 160miles to me £25

[Chris_C]

Right, had another play today, and she's starting everytime now Basically, the renix terminals to the coil had corroded, and needed cleaning. This is a genius piece of French design, cos there is a bloody hole above the contacts to let water in. Nice one Pierre...

Anyway, I'm working on a bribery system now, tell it that if it works properly and behaves itself, it can have more mods, so I start to like it as much as Kar. Seems to be working...

[Chris_C]

F*cking stupid f*cking bloody car, takes the bribe then doesn't start again.

Ok, that one I think was my own fault, still havn't soldered up the earth strap. As Andy posted on my behalf the other day, if you ever stuff one of Volvo's cheap crappy lead battery terminals, DO NOT cut the earth strap and put a new wire on. GET A NEW STRAP (which doesn't work, as they are an obsolete part at Mr V's in his infinite wisdom) or replace JUST THE TERMINAL, which is easier said then done, hence why I cut the strap. I'm off to blowlamp and solder the new wire I have to the strap, hopefully that'll do something.

[Chris_C]

Ok, it's doing it again I'm now on Kars earth strap, so thats good. Only thing I havn't done is hold the king lead near the block to check for spark, will it damage the renix if I do?

I did fit an econ over the weekend, and it is intresting to note that at no throttle, the econ moves somewhere between 2 and 3 o'clock, so about 90 degs of vacuum. Wide open throttle, it goes back to atmospheric pressure.

Today it was raining, so I didn't bother going under the bonnet, and it eventually started after the 6th turning over session (each about 15..20 secs, so I dread to think what my battery is like)

Only thing that has occured, this starting thing has only started since I put the new (s/h scrappy) 400 starter on, but surely that can't make a difference?

[Carl]

Cant see how the starter would be causing the problems. As long as the engine is turning over, then the starter is doing it's job. There's nothing around the starter you could have knocked/dislodged whilst changing it?

Just a thought - are you only having starting problems when it's raining?

[Chris_C]

I don't think I dislodged anything, I did find a bracket floating (holds the +ve wire to starter, so I don't think it can relat to this though) which is need to bolt onto somewhere

And nope, it can refuse to start in perfect sunshine too Any ideas if it would kill the renix if I let it spark onto the block, to see if I'm getting spark next time it plays up?

[jtbo]

Your vacuum works same way as mine then.

Have you cleaned renix connectors and flywheel sensor?

Some car had warm start issues caused by that flywheel sensor, with new sensor it did work, maybe you could pick one from other car if you have many of them?

I think that sensor is same in all models...

Renix in Jeep's is not giving spark unless there is 300rpm or more certain period of time and they have had problems with starting when starter has not been enough good or low battery, but I don't think it is case with Volvo renix?

[Chris_C]

Last weekend I pulled the renix out, found it was using the wrong one (an early 1.7, timing is 2 degs out) and put a correct one in, after taking the coil off and cleaning the contacts.

I had the flywheel sensor off, and cleaned a good 5mm off cr*p off it, but I havn't tested flywheel voltages, I'm hoping this dyno probe circuit will prove that for me.

[jtbo]

You can measure resistance of flywheel sensor and maybe voltage too with multimeter, of course you need to put starter on to see voltage, it is AC (sine waveform, I guess that is the word?).


Here is diagnostics for renix.

[Chris_C]

Right, progress has been made!

Had all the breather pipes off, and cleaned the oily crap that seemed to be inside all of them. Seemingly the coke can shaped thing is an oil separater, but it's useless (unless you take that amount of crap over 172000 miles being not very much... which I suppose it isn't ) Took carb apart, in the first ever (I think) V3M supervised webcast, having a handy expert (Andy... again He must be getting fed up with my cars!) making sure I wasn't about to take something I shouldn't apart!

Stuffed it all back together, and had to adjust the idle screw, must have fiddled something when I was taking the carb apart, of put the choke cable back 3mm different or something.

Now, we have a new thingy happen. I also sussed out this only happens if you try to start between 15ish and 40ish minutes after its turned off from warm. Instead of now it starting, dying all by itself, and then not being able to get it to fire again, no matter how much the thing is turned over, and choke and throttle fiddled with, it now starts, dies, but then catches again on the first turn of the key. It dies soon after, but if a little choke is applied, instead of dying, it tries to die, and manages to ressitate itself. That thing is special Anyway, hopefully means I can now always get started and carry on.

I got a video of this magical behaviour... (bribed mum to stand over bonnet whilst I started it )

From beggining:
Just started 20minutes after its been on a run to warm up
Dies
Starts again, straight away (ish)
Dies
Starts again, put a lil (only 1/4", but the choke seems super sensitive on the 1.7, which is why it revs)
Tries to die, saves itself
I start putting choke back in
Video Ends
I drive off, put choke fully in 100yds up the road

Video exists at www.ecs.soton.ac.uk/~clc202/fakecarb/PICT0155.MOV it is 20megs however.

Any fresh ideas guys? Something is still wrong, Andy is currently passing lots of ideas past me, involving perculation, hmmm, coffee...