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Cold start issues...

Old 03-21-06, 10:53 PM
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Cold start issues...

So, I have a 90 NA. Its always seemed to crank a little longer then it should on cold start. Since I've owned it the idle has always been high so Mr. Cartmill and I took the manifolds off, did some cleaning and some adjustments ect and put everything back together. Adjusted the timing and found that the MAF wasn't connected to a vaccume source (i've only had the car about 3 weeks so im finding some things the previous owner rigged up and fixing them).

We got the idle down but now it seems to be lean serging a little, although I can't find any vaccume leaks. Anyways, on cold start the car cranks for a VERY long time before it finally starts up. Only does it on cold start, when its warm outside, or when the engine is warm, it starts right up, just like it should.

Any idea's? The engine is fairly bare as far as things go. No egr stuff, no ac, no power steering, no air pump, ect. It started much better before we took the manifold off but I'm not sure what we could have done to cause this.

Charles
Old 03-22-06, 10:13 AM
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Surging is a classic example of the TPS being out of adjustment.

and the MAF doesn't have vac connection. Could you mean the boost/pressure sensor on the pass shock tower?

And how cold is cold??? Remember when starting under freezing temps, you should pump the accell pedal once (only one press down and then release) before starting.
Old 03-22-06, 11:38 AM
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Originally Posted by Icemark
Surging is a classic example of the TPS being out of adjustment.

and the MAF doesn't have vac connection. Could you mean the boost/pressure sensor on the pass shock tower?

And how cold is cold??? Remember when starting under freezing temps, you should pump the accell pedal once (only one press down and then release) before starting.

I meant MAP/pressure sensor. Sorry.

Im replacing the TPS, so that should fix the idle problems. I wasn't as worried about those anyway.

Cold as in the engine sat for four to five hours, or overnight. It was prolly around 42 or so when I started it this morning. Like I said, it wasn't nearly as bad before. In the begining it would crank for a few seconds ( three or four at most) and start up. Even when it was 25 outside. Now it takes much, much longer. I would guess around 12 seconds total ( crank for a few, stop, crank for a few). There is no spuddering during cranking. It just cranks and eventually starts right up.

Charles
Old 03-22-06, 01:00 PM
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If the car starts well when warm but not when cold, make SURE the water thermo sensor on the back of the water pump housing is on good and that there is a signal to the ECU from it. I know not what pin on the ECU is on a series five.

The START MAP in the ECU depends on the water thermo sensor for how much fuel it will inject during start. If the wiring is bad and there is no signal, then the ECU defaults to a 176 degrees setting and will NOT inject enough fuel for a good start when cold, BUT it will be good when you start hot because the ECU has defaulted to 176 degrees. Right? Right.
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