Bloody misfire again. Please help I'm going mad!
12-08-2016, 06:12 PM
#51
Re: Bloody misfire again. Please help I'm going mad!
I could've sworn I replied to this. Nevermind.
The motor was stripped down to the valley. So basically I replaced all the gaskets from the inlets up. I checked all the compressions before the motor was removed and everything was fine, once out I checked clearances on the valves and signs of wear and there was nothing noticeable so I didn't tear it down as I know they're a nightmare to reset the lifters on.
It's a misfire. Absolutely no question. Like I said if you play the video through your headphones or speakers with the bass up you'll hear it no problem in the last few minutes when the video is shooting the tailpipes. It's almost a constant miss on one cylinder at that point. Have another listen. Also watch the can on the inlet. When it wobbles there's a miss.
As I said the valves haven't been messed with at all since I first started it. And there was no misfire then.
The motor was stripped down to the valley. So basically I replaced all the gaskets from the inlets up. I checked all the compressions before the motor was removed and everything was fine, once out I checked clearances on the valves and signs of wear and there was nothing noticeable so I didn't tear it down as I know they're a nightmare to reset the lifters on.
It's a misfire. Absolutely no question. Like I said if you play the video through your headphones or speakers with the bass up you'll hear it no problem in the last few minutes when the video is shooting the tailpipes. It's almost a constant miss on one cylinder at that point. Have another listen. Also watch the can on the inlet. When it wobbles there's a miss.
As I said the valves haven't been messed with at all since I first started it. And there was no misfire then.
My bass is always up, still doesn't sound like a misfire to me...
Liek I said before maybe loading up a bit which could cause the excess fuel to burn in the exhaust, but that's not like any misfire I've ever heard, which is why I still don't hear a misfire, sounds a lot like other 60 degree V6s I've owned/heard run. *shrug*
If it was me, I'd just drive it, since you say everything checks out...
12-09-2016, 12:30 AM
#52
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Car: 1984 Firebird S/E
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Re: Bloody misfire again. Please help I'm going mad!
What do you guys mean by 'loading up'? It didn't run like this when I first put it together! I don't know if it's something to do with altering the timing.
I'm gonna start again with the leads from cylinder 1 and make sure they're all in the right place.
12-09-2016, 10:49 AM
#53
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Re: Bloody misfire again. Please help I'm going mad!
http://winaldl.joby.se/aldldata.htm
It is free so just need to purchase an ALDL conversion cable.
What do you guys mean by 'loading up'? It didn't run like this when I first put it together!
I don't know if it's something to do with altering the timing.
I'm gonna start again with the leads from cylinder 1 and make sure they're all in the right place.
RBob.
12-09-2016, 01:19 PM
#54
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Car: 89 RS 89 iroc 87 firebird
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Re: Bloody misfire again. Please help I'm going mad!
not the best way to do it but it works if u dont have a scan tool , or a way to datalog
12-09-2016, 01:59 PM
#55
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Re: Bloody misfire again. Please help I'm going mad!
If you have a laptop can use WinALDL:
http://winaldl.joby.se/aldldata.htm
It is free so just need to purchase an ALDL conversion cable.
Too much fuel, which can easily be caused by a mis-reporting CTS. When they go bad they typically report a colder then correct engine coolant temperature. This wrecks havoc on the fueling as the ECM stays in open loop and adds fuel for a 'cold' engine.
As for the timing, did you use a timing light with the EST/BYPASS connector open?
Never hurts to double check things. #1 plug being on the right hand side of the engine (driver side in the UK).
RBob.
http://winaldl.joby.se/aldldata.htm
It is free so just need to purchase an ALDL conversion cable.
Too much fuel, which can easily be caused by a mis-reporting CTS. When they go bad they typically report a colder then correct engine coolant temperature. This wrecks havoc on the fueling as the ECM stays in open loop and adds fuel for a 'cold' engine.
As for the timing, did you use a timing light with the EST/BYPASS connector open?
Never hurts to double check things. #1 plug being on the right hand side of the engine (driver side in the UK).
RBob.
Thanks for the info on the software, I'll get that ASAP. Is there any lead in particular that we know works with these cars?
That actually sounds like it might be a problem. The car doesn't miss when its cold, and it gets real bad when it warms up. Also my temp gauge doesn't read right. Gauge is reading 89C and shortly after that the fans kick in. I have 3 temp sensors on the 85 2.8 don't i? One in the inlet, one in the head and another inlet sensor?
Yes used a timing light with the bypass disconnected. Then disconnected the battery for a few minutes and reconnected and started.
When you say right side you mean looking as if you're sitting in the car right? Lets just keep is simple as it's a lefthand drive anyway. So it's on the passenger side at the front like this...
WINDSHIELD
5 6
3 4
1 2
COOLING FAN
12-10-2016, 09:49 AM
#56
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Re: Bloody misfire again. Please help I'm going mad!
http://www.moates.net/aldu1-and-cabl....html?cPath=97
http://www.aldlcable.com/products/aldlobd1u.asp
http://www.reddevilriver.com/aldl.html
That actually sounds like it might be a problem. The car doesn't miss when its cold, and it gets real bad when it warms up. Also my temp gauge doesn't read right. Gauge is reading 89C and shortly after that the fans kick in. I have 3 temp sensors on the 85 2.8 don't i? One in the inlet, one in the head and another inlet sensor?
Yes used a timing light with the bypass disconnected. Then disconnected the battery for a few minutes and reconnected and started.
When you say right side you mean looking as if you're sitting in the car right? Lets just keep is simple as it's a lefthand drive anyway. So it's on the passenger side at the front like this...
WINDSHIELD
5 6
3 4
1 2
COOLING FAN
WINDSHIELD
5 6
3 4
1 2
COOLING FAN
RBob.
12-10-2016, 12:52 PM
#57
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Car: 1984 Firebird S/E
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Re: Bloody misfire again. Please help I'm going mad!
Well I disconnected all the leads and started again this morning. THE WHOLE CAP WAS ONE LEAD OUT. So when cylinder 1 was at TDC, the rotor arm was pointing at number 2 lead. Anyway a friend of mine and I re-did everything and re-timed it and hey presto....no misfire!
However the fan is still coming in way too early, the gauge isn't even getting half way and the fan is cutting in. Any ideas?
Can you tell me which of the sensors is a coolant sensor on the inlet as there are two almost side by side and I don't know which is the coolant sensor or are they both coolant sensors?
The one in the head is for the gauge isn't it?
However the fan is still coming in way too early, the gauge isn't even getting half way and the fan is cutting in. Any ideas?
Can you tell me which of the sensors is a coolant sensor on the inlet as there are two almost side by side and I don't know which is the coolant sensor or are they both coolant sensors?
The one in the head is for the gauge isn't it?
12-11-2016, 11:20 AM
#58
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Re: Bloody misfire again. Please help I'm going mad!
The dash gauge/light sensor/switch is in the front of the left side cylinder head.
The two in the front of the intake is the cold start switch and the CTS for the ECM.
The CTS has a black and a yellow wire.
The cold start switch has a tan and a purple wire.
The fan override switch (over temperature) is in the right hand cylinder head, between #3 and #5 cylinders (?).
The A/C high pressure switch is on one of the small high pressure lines on the right hand side of the engine compartment. Note that unplugging the switch should cause the fan to run (w/engine running).
RBob.
The two in the front of the intake is the cold start switch and the CTS for the ECM.
The CTS has a black and a yellow wire.
The cold start switch has a tan and a purple wire.
The fan override switch (over temperature) is in the right hand cylinder head, between #3 and #5 cylinders (?).
The A/C high pressure switch is on one of the small high pressure lines on the right hand side of the engine compartment. Note that unplugging the switch should cause the fan to run (w/engine running).
RBob.
12-11-2016, 11:38 AM
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Re: Bloody misfire again. Please help I'm going mad!
so the plug nearest the thermostat area is the CTS and the one to the right of it is the cold start switch, right? And the sensor to the right with the green wire is the temp gauge sensor, right?
The little circular thing next to the engine lift bracket is the fan override switch right?
12-11-2016, 12:13 PM
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Re: Bloody misfire again. Please help I'm going mad!
Great. Well I've ordered the bits to make the ALDL cable which I'll do before Xmas, then I'll read what the ECM is seeing from the sensors and post it up here as my knowledge will end with those readings. This is all alien to me now.
12-17-2016, 01:54 PM
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Re: Bloody misfire again. Please help I'm going mad!
I haven't made the lead yet but I did a little more exploring today. Temp at the rear sensor is around 100C yet at the front sensor is 67C and the radiator is around 59C. I'm a bit confused that the temperature isn't relative across the motor. Also the temp gauge doesn't get above the first notch before the fan cuts in. Any ideas? Runs a LOT BETTER after I rebuilt the fuel rail and associated bits today.
12-18-2016, 10:38 AM
#63
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Re: Bloody misfire again. Please help I'm going mad!
Also the idle is at 1100 RPM. Is this normal for a stick shift 2.8?
12-18-2016, 11:55 AM
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Re: Bloody misfire again. Please help I'm going mad!
Well I definately don't have a vacuuum leak as I've tested all that when I had the original running problem. And it's not in diagnostics mode either. Although it is still on the stock chip without EGR, airpump, or carbon canister so I'm guessing that will upset it.