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Location:
Adelaide
Registered:
May 2002
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2tg EFI problems, car idles but wont rev....
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Wed, 21 May 2003 09:33
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have a 3T/2TG hybrid with 2tg EFI manifold, 3TGTEU injectors, Microtech MT-4 ECU, 4AGE TPS adapted to the 2TG TB with a VL commodore efi fuel pump...
was goin to work the other mornign when the car just stalled out.... now the car will start.... it will idle, but it wont rev...
while it idles if I try to rev it fast, like open the throttle right up, it'll cough, splutter and then backfire through the inlet.... while it idles I can ever so gradually rev it up, like slightly increase the amount of throttle and it'll kinda rev up, but nothing like it should.... it seems to break down and not fire, or run out of fuel when I rev it...
Talked to mechanics, possibly fuel pump, so I changed filter, and they gave me another VL efi fuel pump, fitted that, and it still does the same thing.... could it possibly be something spark related ?! I poulled out the plugs, cleaned them, they were as black as black. I have electronic ignition, and borrowed one off a mate aswel, and I'll try fit that tomorrow.....
does anyone have any idea's ?!
Brendon
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Location:
Hornsby, N.S.W
Registered:
September 2002
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Re: 2tg EFI problems, car idles but wont rev....
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Wed, 21 May 2003 14:22
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my first thought was going to the filter but as i read on you have already changed that, have you ever had the enjectors flow cleaned??? any kinked fuel lines anywhere??? check your points clearance!!! also your tps sensor.
justin
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Location:
Brisbane
Registered:
December 2002
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Re: 2tg EFI problems, car idles but wont rev....
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Thu, 22 May 2003 04:06
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I don't rally know all that much on this but check your Air Flow Meter. It is the main thing that tells the computer how much fuel (injection duration) to deliver. if for some reason this is altered then its ratios will be out. I tried this when I had the AFM cover off the other day, if I turned it ever so slightly more open it just died in the ass. Check the spring tension out. it might not be as big a problem as you think.
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Location:
Brisbane
Registered:
May 2002
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Re: 2tg EFI problems, car idles but wont rev....
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Thu, 22 May 2003 04:24
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hey
An MT4 uses MAP, manifold air pressure to sense changes in the engine for fuel changes to the engine, so it ain't got no air flow meter!!! 
I'd be checking you timing to make sure it hasn't changed, sounds like when you put your foot down, the timing is retarding way too much, the reason for the backfiring out of the manifold. If you do it slowly, it doesn't cthe vacuum level doesn't change, so you advance, and weights for retardation in the dissy don't change the timing, thats why you can slowly put your foot down.
Another possible cause, is that the coils is leaking to ground, breaking down the spark at the plugs, or the plugs are stuffed.
had the leads break down on my once, and the coil, the engine would idle ok, run without load ok, but as soon as you applied load it would do extacly the same thing as your.
Cheers Nilezy
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Location:
Brisbane
Registered:
May 2002
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Re: 2tg EFI problems, car idles but wont rev....
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Thu, 22 May 2003 06:19
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I'd do a bit of diagnosing first, instead of taking wild guesses.
- Check the signal of your MAP sensor is within spec. A dodgy sensor can cause all sorts of dramas.
- Put a pressure gauge on the fuel rail (should be a constant ~35psi). If that's OK you know the fuel system is not the problem.
- Get a timing light and check your base ignition timing, mechanical advance and vacuum advance are within spec.
- If all else fails, take the car to a shop with a dyno and full spectrum gas analyser. This is the ultimate diagnostic tool if your engine is running badly.
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Location:
Adelaide
Registered:
May 2002
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Re: 2tg EFI problems, car idles but wont rev....
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Thu, 22 May 2003 09:53
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ooooooook.... after another day of fart assing
ok, no, there is no airflow meter, as someone said. it does use MAP, but we are actually running it with TPS mode... so it mainly uses the TPS, because I have worked cams with huge overlap therefore causing varied vacuum at idle....
ok, other things tried today.... we put NEW plugs in, it started first pop, reved up like normal and was sweet.... then I noticed the amount of BLACK smoke pouring out of the exhaust... ei running rich.... ran car for about 4 minutes.... turned it off. then started it again and then it started playing up again, not r4evving properly... took a plug out, they're black as black.....
then I thought, what would make it run so rich... coolant sensor could be faulty, and then causing the computer to add way too much fuel ?! so we put a multi meter on the plug. now, I don't know what resistance, ohmage or whatever about all this kinda crap, but it does seem a practical kinda excuse...
Things learnt today.... spark plugs cost me $12 and now I need new ones again cos these got all blacked ! ok, so yeah, it's goin to my mechanics on monday but I was trying to get a bit of an insight.....
I am also trying to get my hands on a Handset for the ecu so I can do a system check which will tell me straight out if the TPS is functioning properly, and also if the Water sensor is working properly too.
well there is a few idea's for tomorrow.
Thanks all for ideas
Brendon
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Registered:
May 2002
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Re: 2tg EFI problems, car idles but wont rev....
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Fri, 23 May 2003 00:55
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things i've been thinking of-
-has your MAP vacuum line been kinked or come loose?
-take the cover off and check your TPS, maybe check all wires from TPS to computer.
-The dizzy does advance when i sucked on the vacuum, but the advance thingo looked loose, try replacing the distributer.
-no chance the computer could have reset some of the values is there?
-blocked injectors.
looking at an toyota EFI manual page ive got, the thermo sensor has around 5kohms at 0degrees c, then as engine warms resistance goes down to around 0.5kohm at 60 degrees C. so if you have like a 0.5kohm resistor (from dicksmiths) try that, or just try replacing it. you said you had like an 8kohm or something last nite, which would mean the engine was at minus 20degrees!!
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Location:
Adelaide
Registered:
May 2002
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Re: 2tg EFI problems, car idles but wont rev....
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Fri, 23 May 2003 05:46
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you don't have a spare one laying around do ya mate ? temp sensior that is.
cos if you say it could be at -20 then imagine how rich the computer would make it for it to run.......
like I said, tried again last night, and that's what happened, it's definately gotta be something makeing it running WAY too rich.
Brendon
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