Posts: 338
Threads: 23
Joined: Sep 2017
not entirely sure what the hell to do now.
Friday - started and ran pretty well after getting the 2 fuel leaks sorted and stage 1 exhaust on
Saturday - Cranks but no fire: checked fuses, relays, inertia switch and grounds
Sunday (Today) - still no fire even with a little brake cleaner and all plugs removed and cleaned (I did 1 at a time so HT leads wouldn't get mixed up), checked for spark which I do, and added 5L to the tank and still nothing.
so I'm not sure what I'm missing but I haven't touched anything that could stop the car from starting, Facebook lot aren't being very helpful by telling me "check grounds" or "battery is failing" even though I'm getting a good spark from the plugs.
could the ignition ecu be on its way out or one of the relays? I get a re-prime on failed start and I hear the relays clicking so I have no idea what's wrong
Help 
Posts: 1,746
Threads: 119
Joined: Aug 2009
Have you tried jam jar testing your injectors?
When was the last time you changed your fuel filter?
What is your primary fuel pressure (especially important if you’ve now added a free flow exhaust on to the engine)
Rissy
(Forum Member 288)
(DOC Member 663)
May 1981 vin#1458 "LEX"
Grey, Flapped, Black
Chassis: #1073
Engine: #2839
Main Car(s):
2005 BMW M3 in Velvet Blue
2010 Honda Civic Type R in Sapphire Blue (1 of 115 made)
Posts: 338
Threads: 23
Joined: Sep 2017
(20 Aug 2023, 18:33)Rissy Wrote: Have you tried jam jar testing your injectors?
When was the last time you changed your fuel filter?
What is your primary fuel pressure (especially important if you’ve now added a free flow exhaust on to the engine)
fuel filter was replaced just before I bought the car and injectors haven't been tested but would be super odd for all 6 to fail at the same time since I had it running friday.
haven't tested for fuel pressure yet but it had no trouble starting first 2 times after it was put on  but I'll run a test on it just in case
Posts: 1,746
Threads: 119
Joined: Aug 2009
Have you ever changed the fuel accumulator?
It's worth doing a fuel pressure test. There's two tests you want to do there (I'm basing my suggestions on you insisting you have good spark, so electrical input should be good). You need fuel, air, and spark. Air wouldn't normally be an issue, unless you're trying to start the car in the vacuum of space.
Test 1: Primary fuel pressure to record what it is from the pump. You'll be on a cold engine, so you need to refer this to the bottom of the workshop warm up curve.
Test 2: Fuel accumumlator holding pressure. If your accumulator is ok, then you'd expect it to be holding reasonable pressure (refer to the workshop manual for the excepted range and time, I can't remember these off the top of my head - I think from my memory on my car, the fuel pressure held up in the acceptable range for about 1hr).
Have you tried forcing the cold start injector to fire by swapping your grey fuel pressure regulator plug on to it (to replace the blue one which is supposed to be on there). Worth a shot too, as you might find that this extra spray of fuel kicks the engine, thus proving your spark and guiding you to the fact it is suffering fuel starvation and not starting.
Are the battery terminals on your battery ultra clean and shiny? (Just checking)
Rissy
(Forum Member 288)
(DOC Member 663)
May 1981 vin#1458 "LEX"
Grey, Flapped, Black
Chassis: #1073
Engine: #2839
Main Car(s):
2005 BMW M3 in Velvet Blue
2010 Honda Civic Type R in Sapphire Blue (1 of 115 made)
Posts: 338
Threads: 23
Joined: Sep 2017
(21 Aug 2023, 07:32)Rissy Wrote: Have you ever changed the fuel accumulator?
It's worth doing a fuel pressure test. There's two tests you want to do there (I'm basing my suggestions on you insisting you have good spark, so electrical input should be good). You need fuel, air, and spark. Air wouldn't normally be an issue, unless you're trying to start the car in the vacuum of space.
Test 1: Primary fuel pressure to record what it is from the pump. You'll be on a cold engine, so you need to refer this to the bottom of the workshop warm up curve.
Test 2: Fuel accumumlator holding pressure. If your accumulator is ok, then you'd expect it to be holding reasonable pressure (refer to the workshop manual for the excepted range and time, I can't remember these off the top of my head - I think from my memory on my car, the fuel pressure held up in the acceptable range for about 1hr).
Have you tried forcing the cold start injector to fire by swapping your grey fuel pressure regulator plug on to it (to replace the blue one which is supposed to be on there). Worth a shot too, as you might find that this extra spray of fuel kicks the engine, thus proving your spark and guiding you to the fact it is suffering fuel starvation and not starting.
Are the battery terminals on your battery ultra clean and shiny? (Just checking)
I replaced the fuel accumulator just before the nec last year as the old one had completely died where i couldn't start. So that should be okay unless i got a "friday" unit and is failed on me
I haven't tried the plug swap yet as we were trying to eliminate and spark issues but since trying a little brake cleaner on turnover didn't result in anything i feel it'll be the same situation
Posts: 1,746
Threads: 119
Joined: Aug 2009
Who’s “we”? You got someone helping you?
Rissy
(Forum Member 288)
(DOC Member 663)
May 1981 vin#1458 "LEX"
Grey, Flapped, Black
Chassis: #1073
Engine: #2839
Main Car(s):
2005 BMW M3 in Velvet Blue
2010 Honda Civic Type R in Sapphire Blue (1 of 115 made)
Posts: 49
Threads: 2
Joined: Apr 2019
On the Facebook message you mentioned slow crack hence people suggesting bad connections and batteries. Are you now cranking at full speed? If it's slow it doesn't matter if you have good spark etc. as you will need to sort out the starter first.
Posts: 338
Threads: 23
Joined: Sep 2017
(21 Aug 2023, 11:29)Rissy Wrote: Who’s “we”? You got someone helping you?
Me and mich were trying to diagnose the issue when we removed the plugs
(21 Aug 2023, 22:55)acmetowers Wrote: On the Facebook message you mentioned slow crack hence people suggesting bad connections and batteries. Are you now cranking at full speed? If it's slow it doesn't matter if you have good spark etc. as you will need to sort out the starter first.
It just seemed slower to me than normal thats why i mentioned it but its been verified that cranking is normal speed, i had replaced the starter as one of the first jobs i ever did 2 years ago now
Posts: 1,746
Threads: 119
Joined: Aug 2009
I only asked if you had someone working with you, as I thought you had Mr Hanlon and/or Mr Westerman on the case, and both these chaps know their stuff, so they should have been able to get to the bottom of it with a bit of time. I’m not sure who Mich is, so don’t know his strengths.
Did you say you’ve upped your fuel/air mixture with this new exhaust? Upping fuel/air mixture is not adjusting pressure, just richening/weakening the mixture. Have you tried putting that back to where it was? You could be too lean/rich now….?
Rissy
(Forum Member 288)
(DOC Member 663)
May 1981 vin#1458 "LEX"
Grey, Flapped, Black
Chassis: #1073
Engine: #2839
Main Car(s):
2005 BMW M3 in Velvet Blue
2010 Honda Civic Type R in Sapphire Blue (1 of 115 made)
Posts: 695
Threads: 28
Joined: Jul 2006
Quote:could the ignition ecu be on its way out or one of the relays? I get a re-prime on failed start and I hear the relays clicking so I have no idea what's wrong
Are you sure you are hearing "priming" and not just your lambda frequency valve buzzing for a second?
First thing to check is that you fuel pump is actually running whilst you're cranking. High on the suspect list is the rpm relay. You don't need to run off and buy a new one.
Just unplug it and plug a jumper link from purple/white wire to the opposite corner - brown wire
That should cause your fuel pump to spin up immediately - even without keys in the ignition.
Try and start it then. If you pump doesn't spin up at all, either your RPM relay is bad (you still don't need to run out and buy a new one) or your fault is elsewhere
Posts: 338
Threads: 23
Joined: Sep 2017
(22 Aug 2023, 09:11)Rich H Wrote: Quote:could the ignition ecu be on its way out or one of the relays? I get a re-prime on failed start and I hear the relays clicking so I have no idea what's wrong
Are you sure you are hearing "priming" and not just your lambda frequency valve buzzing for a second?
First thing to check is that you fuel pump is actually running whilst you're cranking. High on the suspect list is the rpm relay. You don't need to run off and buy a new one.
Just unplug it and plug a jumper link from purple/white wire to the opposite corner - brown wire
That should cause your fuel pump to spin up immediately - even without keys in the ignition.
Try and start it then. If you pump doesn't spin up at all, either your RPM relay is bad (you still don't need to run out and buy a new one) or your fault is elsewhere
It could be that but to me it sounds like it buzzes the same when the rpm relay is clicked in, I'll try the jumper link just in case, but i can smell fuel and there is pressure on the inlet flap byt still worth a shot
(22 Aug 2023, 07:08)Rissy Wrote: I only asked if you had someone working with you, as I thought you had Mr Hanlon and/or Mr Westerman on the case, and both these chaps know their stuff, so they should have been able to get to the bottom of it with a bit of time. I’m not sure who Mich is, so don’t know his strengths.
Did you say you’ve upped your fuel/air mixture with this new exhaust? Upping fuel/air mixture is not adjusting pressure, just richening/weakening the mixture. Have you tried putting that back to where it was? You could be too lean/rich now….?
Mich is one of the newer owners, who lives close to me, he was at the gbcj delorean day last year.
I haven't tweaked the mix levels yet since it was running okay when it started last time, I'll run the pressure test at the weekend since i will need some new washers
Posts: 1,335
Threads: 141
Joined: Jul 2006
Yep, try Richs suggestion of jumping the RPM relay, very quick and easy to do.
I have been helping William out at the earlier stages but I haven't been up just recently having been away and have a number of out of work commitments over the summer months.
Richard Hanlon
Derbyshire
DOC 393
1981 DMC-12 VIN 06126
Posts: 338
Threads: 23
Joined: Sep 2017
Hopefully we'll see if the rpm jumper trick works, because its very strange that it has everything set to start yet isnt
Posts: 1,746
Threads: 119
Joined: Aug 2009
If it does turn out to be your RPM (Fuel Pump) relay which has gone faulty (despite having fuel pressure at the venturi port?), then you can easily buy a spare (new) unit.
I bought one of these years ago. Tested, and proved it worked ok on the car, and then swapped back in my original black unit, but keep this one in my glovebox as my hot swappable spare (in case). It's worth keeping a spare available in the car. (Instead of jumping over the contacts on the plug as Rich has suggested as a test)
https://www.ebay.co.uk/itm/364407446703?...R47Xg5rEYg
Rissy
(Forum Member 288)
(DOC Member 663)
May 1981 vin#1458 "LEX"
Grey, Flapped, Black
Chassis: #1073
Engine: #2839
Main Car(s):
2005 BMW M3 in Velvet Blue
2010 Honda Civic Type R in Sapphire Blue (1 of 115 made)
Posts: 695
Threads: 28
Joined: Jul 2006
Quote:I bought one of these years ago....
https://www.ebay.co.uk/itm/364407446703?...R47Xg5rEYg
That's a good price Rissy. Top find that.
If you have fuel pressure at the metering head and spark at the plugs, next thing to check for is air. If your idle speed motor is stuck closed, it won't start.
With your ignition on, grab hold of the motor. Can you feel it vibrating? It should quite strong. You should also be able to hear it humming ....
|
