Another GTV6 won't start issue

Started by Albygtv, September 09, 2012, 01:50:18 PM

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colcol

The MSD is a brand of coil, see if you can find out if the original coil is a resistor type, or non resister type, the resister type has a resister block, that has 12 volts going into one side, and the other side has the volts knocked down to say eight volts, this wire goes to the + side of the coil, then there is a second wire that comes directly from the starter motor, and when the starter motor is engaged, it sends the direct battery current to the coil, and this may be say 10 volts, so that the coil gives the spark plugs a big fat spark to start the car, but only when the starter motor is engaged, if you have a resister coil, then check the volts on the + side of the coil, also put a test light on the - side of the coil, and when the starter is kicking over, the light should flash on and off, Colin.
1974 VW Passat [ist car] 1984 Alfa 33TI [daily driver] 2002 Alfa 156 JTS [daily driver]

shane wescott

My three simple ones for the basics (fuel, spark, compression).

1. Fuel. On the drivers side of the plenum at the front are two small vacuum leads. Take either one off and spray some "Start Ya Bastard" in (gota luv that product).

turn the starter and if there is spark and compression IT WILL KICK.

So if you get a kick it is down to a fuel issues - my isses have all been around fuel pump realy from there. UIf you move the AFM vane with ignition on you will hear the pump, and the return valve sending fuel back to the tank.

2. Spark. ColCol and I were laughing about this yesterday - find a gullible friend and say " Hold This" while you crank it over. If his hair turns to Afro and he starts chasing you - you can be pretty sure there is a spark. If he just looks at you and says "What For" - dead spark it is.

If you dont have any friends that stupid I've used a timing light in the past as a spark detector. Hook in the top of the coil first and work it from there.

3. Compression. I have a compression tester but if you dont I suppose you could remove a spark plug and see if pressure comes out on start.

Obviously these are basic backyard dummy mechanic steps and apologise to anyone who is a trained mechanic.

I just work in IT and love fixing Alfas :-)

Catch ya

Shane
Current Cars:

No Alfa's :-(

Previous Cars:
1991 White 164
86 White GTV6 Zender Body Kit
90 Red 75 TS
98 Blue GTV 2.0
85 Red 33 1.5 TI
85 Red 33 1.7 Carby
83 Silver 33 1.5 GCL
70 Blue Berlina 1750
70 White Berlina 1750

70 White Berlina 1750 (my first)

Current Bikes:

2002 Yellow Ducati ST2 944

colcol

When kicking over GTV6, get a remote starter OR make one with a 12 volt switch, 1 wire to battery and the other wire to starter solenoid switch, [the terminal from the ignition switch], now you can kick the engine over from the engine bay, now take a spark plug and connect it to a spark plug lead, now go to the inside of the car and put the handbrake on OR put bricks or lumps of wood to chock your wheels, put it into neutral, switch the ignition on, now go to the engine bay and kick the engine over, while shorting out the spark plug against the engine, no spark, ignition problem, spark present fuel problem, Colin.
1974 VW Passat [ist car] 1984 Alfa 33TI [daily driver] 2002 Alfa 156 JTS [daily driver]

Albygtv

Eureka, have a runnuing GTV6 again. Difficulty seems to have been that there were two problems, one of which was intermittant, and possibly a third issue, being my ignorance of these cars and just how meticulous you have to be in narrowing down the possibilities.

Firstly, found a new MSD coil available in Dandenong, so shot out there yesterday and picked one up. Installed it yesterday afternoon and turned her over - didn't start but for the first time, sounded like it was trying to but just not quite catching. Definately had a good spark.

Had a rest and went back to it today. Exactly the same as yesterday, almost on the verge of starting but not quite. Tried some more Start you Bastard and with a few more turns it fired up. Hooray. When I touched the accelarator it died. Started it a few more times without needing Start you Bastard but each time I left it for more than a few seconds or touched the throttle it died. clearly now had  a common problem that I've read a lot about in the last few weeks, so knew what to start checking. First thing was TPS but it clicked properly. Second was double relay and, sure enough it was not clicking or starting the fuel pump when opening the airflap with ignition on. I'd done this same test quite a lot of times in the past few weeks and it always worked fine. Now it wasn't working. Fiddled with the wires , no change. Fiddled some more and thumped the relay with my palm a few times - it started working. Started engine and it kept going and responded to throttle. - double hooray. Stopped and started a number of times and everything seemed fine, so just went for a 40 minute blast and the car ran great.

So, next weekend will have another look at the double relay and its wiring as this is clearly intermittant and therefore could happen again. Then its on to some of the things on my "improvement" list to keep me occupied over summer - might have to add a megasquirt to the list as it allows for future changes whilst possibly simplifying the underbonnet items a little. Can't wait.

Big thanks to everybody who responded with suggestions. I tried most of them and eventually got there and learnt a heck of a lot about these engines. All worthwhile. This is a great forum and a huge part of the pleasure in owning one of these cars. Big, big thanks.

Al Campbell

MSD blaster is a replacement coil. Used one on my car.

I'd replace that double relay.

Starts but dies as soon as you touch the accelerator is a common issue. Unfortunately I can't remember what the cause is. Do some searching maybe on Greg Gordon's check list first.

AL.

Albygtv

Thanks Al. Yes, I've already ordered a double relay and will replace as soon as it arrives. I've also studied everything I can find on this condition and must admit that I'm a bit puzzled. The prime cause of the start then stops syndrome seems to be that the car starts on fuel from the cold start injector but stops when this stops because the other injectors don't kick in. There are quite a few reasons the main injectors might not kick in, and most of these are to do with the fuel pump not starting when its supposed to and getting fuel to them. The double relay is one of the reasons the fuel pump might not start, and others include various wires not connected properly or the AFM flap not opening, the fuel pump being s_____d and so on.

My question is, how does the cold start injector get its fuel if the pump is not starting? Does the pump run for a short period just on ignition to pressurise the CSI and then turn off and wait for the AFM flap to open to restart and pressurise the other injectors?  Not very important really, but I'm curious.

The other thing that's happened is that I drove the car to work this morning through peak hour traffic. The idle on this car has been high since I got it - about 1400 rpm (and that's on my list for fixing this weekend). However, this morning whenever the car was idling (which was quite a lot in peak hour) it hunted or surged continuously between 1200 and 1400 revs. Ran perfectly above idle and the surging happened both when the engine was cold and when it was well warmed up. It did not surge when held at steady revs above idle speed. This is new - I'm sure it was not happening before the other non-starting issues. Again I'll be looking at this over the weekend but can't recall ever reading about it in the 100's of pages I've looked at so far. So, while its not desparate I would be interested to hear if anyone else has solved this problem previously.

dehne

hi there
I am, thinking off memory that if the cold start injector does not shut off this happens, i had that with my 90 years ago and my fix was just disconnect it. has been off for about 5 or 6 years now.
another  thing is on the drivers side of engine rocker cover take all the bits off and clean them all they get gunk in them (cant remember tech names).
Wehn I have a prob like this I clean everything poss thats easy to get to, also new plugs, oil, and run some injector cleaner through to. 
now
1x 85 mdl road 90
2013 Giulietta 1.4
2015 Launch Edition Giulietta
Past
Multiple Alfa 90's, Alfetta's and 147's

aggie57

Alby - the fuel pump runs for a couple of seconds when the ignition is turned on and then stops.  That is what provides the fuel to the cold start injector.

There is a signal out from the ECU to the double relay that is switched on when you start car.  I can't recall what actually triggers it but recall it has something to do with the ignition.  Once that signal is active there is a 12 volt supply to the double relay; voila - engine runs. 

If the AFM flap stays shut the main injectors still get fuel.  Just not much air!
Alister
14 Alfa's since 1977. 
Currently 1973 GTV 2000, 2020 911 C2S MT, 2021 Mercedes GLE350, 2023 Polestar 2 LRDM
Gone......far too many to list

Mat Francis

My first guess for the hunting idle would be air leaks somewhere in the system. The other thing I would check is the throttle position sensor. Will take you about 5 minutes. The procedure for this is well outlined in Greg Gordon's L Jet guide.

My TPS wasn't adjusted properly. The car would start normally, idle perfectly at about 1k until you touched the throttle- then it would idle anywhere between 1 and 2k. After I adjusted it so that the sensor would read that the throttle was actually fully closed, it now idles perfectly. (and also doesn't hugely over fuel itself under mid range throttle because WOT was being triggered at about 30% throttle).





'83 Alfetta Sedan TS
'88 75 3.0
'85 Land Rover County
'87 Land Rover Perentie

Al Campbell

If the idle speed has been raised to get over issues of not idling whilst cold, you can reach a point where the L-Jet thinks it's on over run. Conditions are:
1. TPS switch is in "closed" posi. Revs are above "normal" idle. L-Jet thinks "O.K. you've just backed off, I'll cut the fuel to the injectors to reduce emissions."
2.  Revs then drop until the L-Jet thinks "Uh Oh, idling and the revs are too low, better open up the injectors." Revs then increase until condition 1 is reached again. Happens when warm, revs ramp up then suddenly drop, then ramp up again. Round-and-round it goes.
3. I used to then go into a state of embarrassment at traffic lights as I sounded like a T***ser pumping the accelerator.

Other issue I had with idling was a clogged up "vacuum regulating valve" (only on Australian & Swedish cars" – picture attached). Took ages to find this was an issue. I think the oily goop blocks it when cold, then when engine is good & hot it leaks air back to the intake, raising the idle, maybe enough to cause hunting. The device is supposed to cut emissions in the event when you suddenly back off at high revs, causing too much vacuum? Given the amount of smoke my engine was blowing after 30 years I just disconnected the sucker and plugged all the holes.

AL.

Albygtv

Hey thanks guys for lots more good suggestions. And Al, your description of sitting at the lights feeling like a tosser was spot on - exactly the symptoms and the feelings I was getting.

Problem has quickly got worse with significant swings in idle rpm, so I won't drive it in heavy stop start traffic until its fixed. Amazingly still runs extremely well as soon as I hit the throttle. Anyway, its all made me realise that a good going over of everything related to the engine / fuel injection will be well worth while - after all, its all pretty old by now. So, should get the new double relay tomorrow and have just ordered a silicon vacuum hose kit from Greg Gordon. I plan over the next few weeks to look at all the suggestions you guys had and go through most of the processes Greg Gordon documents for getting the fuel injection working just right. Hopefully I'll then end up with a car that not only starts and runs well, but will keep doing so for a long time. (well, that's the hope anyway).

Will report after the weekend. Cheers.

Al Campbell

I never really got on top of satisfactory idle during the warmup period from dead cold ~ first 5 minutes. Really need a replacement for the AAV, or replace the L-Jet. I had resistors in series with the heating coil in the AAV to make it warmup more slowly as first thing in the morning I was often sitting at lights with very short drives in between. I more or less had to reset the idle ever 4 months for the change in season. "What Cheese me Off!" is having to feather the throttle at traffic lights in a car with electronic injection. :P

Al.

Albygtv

One of the items on my list for this weekend is a good clean of the AAV. Hopefully that will help. I notice Greg Gordon goes in for manual AAV's so you don't have any problems but do have virtually a choke cable to pull out on cold mornings. I think that would also cheese me off on a car with electronic injection, but might be a last resort if all elsefails. Cheers

Al Campbell

I tried two AAVs, cleaned them, adjusted them. Didn't make any difference. Little suckers never closed fully. didn't move a whole lot from frozen to hot. Saw a thread where someone pulled one apart recently. The long "shaft" holds the bi-metallic strip. The characteristics of the two metals must age over time, losing their temper (or work hardening) and the movement of the strip must be less than it was when new.

The Greg Gordon solution is a heater valve with a choke cable. I thought about making one with a temperature controlled actuator. Something like a Solenoid or R/C servo? There are also PWM controlled bi-pass valves available - saw one on a MegaSquirt Thread.

Good Luck,
AL.

Albygtv

Some good news and some bad news. Good news is that the idle hunting problem is completely cured (at least for today, fingers crossed, touch wood) - idle is now absolutely steady without a flicker of movement in the tacho needle. Engine even feels a bit smoother, crisper and more responsive at low revs.

Bad news is I don't know what fixed it. I could see my weekend was going to get away from me, so when I had a spare 30 minutes today I thought I'd just go and do a few basics on the car that were not likely to fix anything. but at least would provide a good basis for more work tomorrow. So went out and put on the new rotor cap I'd ordered, also the new double relay, removed the "vacuum regulating valve" as suggested by Al (although I discovered when looking at it that someone had already disconnected and plugged the inlet hose) and finally, did a quick adjustment of the idle to bring it down to more reasonable revs.

Then thought I'd take it for a quick drive just to see if this work had changed anything. Lo and behold, the result was as per the "good news" above. Of course, I'm very happy about this, presuming it lasts, but it would have been nice to know which item or combination of items caused the change. It might have even just decided to stop sulking and behave itself because I left it sitting unloved for a few days - although I think this is unlikely as I've read lots of threads relating to "running" problems and they never seem to fix themselves, no matter how long we leave them alone.

By the way Al, I'm going to look more into AAV's. There must be a better solution out there somewher. I've had some early 70"s Renault Gordini's and Alpine Renaults with the even earlier D-jetronic injection. Their equivalent of an AAV was very similar but instead of the electric warming, they simply had a section going down into the water jacket which heated up at the same rate as the engine. Sounds very simple, but they never seemd to give any trouble at all. even though they were 10 years older. Will see if I can find anything else.
Cheers