Question about timing...

General Bellett, Gemini 75-98, Piazza 81-93, Bellel, Florian, 117 Coupe, Minx, Aska technical discussion.
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impulsive
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Post by impulsive »

Yup, my dizzy has that little mark too. OK. I'll post an update here with the results soon.

Bart
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OK, got everything put back together, I am 100% sure my timing is dead on, and it is pretty much doing the same thing. I crank, it starts and then dies right away.

I am going to run a compression test next, just to cross it off the list, even though I do not think that is the issue.

I am back to thinking this has got to be electrical or fuel related, both which seem to be complex to sort out.

Bart
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OK, here's an update.

All four cylinders read 120 for the compression test.

I have jumpered the fuel pump to give constant 12v and this changed nothing.

I have spark.

I have fuel to the rail, and I believe my injectors are working (plugs wet after I pull them).

I have oil pressure.

Unless there is something really screwy going on with the harmonic balancer, my timing is correct.

Car starts, runs for a few seconds, and dies.

This leaves air. Suggestions?

Thanks - Bart
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Post by Bugle »

Airflow meter?
Maybe it starts without an airflow meter signal then after a few seconds switches to the AFM and fails..
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Post by impulsive »

Bugle wrote:Airflow meter?
Maybe it starts without an airflow meter signal then after a few seconds switches to the AFM and fails..
Are you talking about the MAF or the IAC?

Bart
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Post by Piazza_man »

I'm thinking the TPS might be playing up if it's not the Airflow meter.
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Post by Bugle »

impulsive wrote:
Bugle wrote:Airflow meter?
Maybe it starts without an airflow meter signal then after a few seconds switches to the AFM and fails..
Are you talking about the MAF or the IAC?

Bart
MAF is the airflow meter, IAC wouldn't stop it running, just make it idle too fast or slow.
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Post by impulsive »

I actually have two MAFs, and I have tried them both with no change.

Another thought I had, if it was a sensor giving me issues, I would think I would get a CEL with a trouble code, no?

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Post by wedgenut »

The only time I have come across this EXACT behaviour is with the IAC circuit, not the valve itself. There is a large black hose that runs from the throttle body down through the manifold runners to the IAC, from under the IAC there is another hose that runs in a loop back up to a pipe on the bottom of the Air plenum. If this hose has come off the plenum (and it is easy to accidentally tug it off when wriggling your hands down in that area checking other things) YES I"M still talking about the car, not what you do in your spare time when no one is looking. What you are experiencing is EXACTLY WHAT HAPPENS IF THIS HOSE IS OFF. It fires and starts and then dies immediately. I have mentioned this before a million posts ago. Double check and triple check this hose. The IAC action is as follows. When engine cold the passage is open to admit controlled extra air to the inlet through the orifice of the valve and the car idles up. Voltage is applied to this valve when the engine starts and it slowly starts to close, finally closing fully and your idle speed normalises. On some more modern cars the IAC is dynamic and will adjust to suit conditions from signals sent by the ECU in response to information it receives from water temp, O2 sensors etc etc. The piazza isn't like that, it is a simple open when no voltage and closed with voltage, although closing is a slowish process rather than instant. If the hose is off the plenum you will be getting too much extra air into the plenum. It fires because you have compression and fuel at first crank but can't stay running because of uncontrolled air passage.
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Post by impulsive »

Thanks, wedge, I think I am getting mightly close.

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OK, can someone clear this up for me please? Here is a picture I found online of a JR engine bay from an '87 turboed car, just like mine. My car, is missing #2 in the picture. The previous owner took this part out because it was leaking, and he said this part was the OEM fuel pressure regulator. His shop replaced it with a Bosch Fuel Pressure regulator meant for BMWs. The problem I am having I believe might be fuel related so I am trying to get these bits sorted. Looking at a parts catalog, the part that is missing does not seem to be the fuel pressure regulator. The fuel pressure regulator looks like #3. So is #2 just another fuel damper like #1?

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Right now, I can get the car to start. I can press on the throttle and keep it running for a few seconds. I will die immediately if I do not give throttle. I get no CEL. No codes are thrown, but the car wants to die. I have a fuel pressure gauge between the damper (#1 above) and the fuel rail. Fuel pressure is around 48psi, which I think is too high. So my theory is, I am flooding out my cylinders and that is why the car keeps dying out. Either that, or I have a problem with my distributor.

I am sure my timing is correct.

Thanks - Bart
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Post by wedgenut »

yes No. 2 is another fuel pulse damper, it is in the line between the rail and the regulator. Fuel pressure is a little high, it shoulkd be around 35psi with vacuum pulled on the regulator hose and 42 without. This isn't likely to flood the engine. Running and wanting to stop isn't ignition timing and it isn't likely to be lack of fuel. The missing damper is not likely to cause this problem either. DID YOU CHECK THE IAC HOSES?
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Post by impulsive »

wedgenut wrote:DID YOU CHECK THE IAC HOSES?
Thanks, wedge, yeah, nothing disconnected under the plenum. I also tried switching the plugs under there, the IAC and knock sensor plugs are the same. This changed nothing. I am still at a loss. I have yet to pull the rail and check the injectors. I do not get a CEL so no codes are thrown. I would think if I had a bad sensor, I would get a CEL and a code. I tried jumpering the fuel pump to get constant 12v and the problem is the same, so I know fuel pressure is not dropping off once the car starts. The other guess I had was the distributor is bad. Its expensive as all hell to replace, but I might try a new one.

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Post by wedgenut »

If you get stuck I have a spare known to be good Dizzy but it needs to be compared to make sure it is exactly the same, Our cars and the JDM versions may not be the exact same as the Impulse. If you wanted to make your car original I have all the EFI gear to put your car back to the way it should be. It is only money and shipping cost LOL.
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wedgenut wrote:If you get stuck I have a spare known to be good Dizzy but it needs to be compared to make sure it is exactly the same, Our cars and the JDM versions may not be the exact same as the Impulse. If you wanted to make your car original I have all the EFI gear to put your car back to the way it should be. It is only money and shipping cost LOL.
Thanks, I appreciate the offer, I might take you up on it sometime. Right now, mate, I just need to get this problem sorted.

Bart
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