3.0 Conversion question

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dcefali
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3.0 Conversion question

Post by dcefali » Fri Mar 17, 2006 7:51 am

I recently transplanted an '89 Verde 3.0 into my '86 GTV6. I reused everything (FI) from my 2.5 onto the 3.0. but now the car is really hard to start from cold. You absolutely must not touch the gas pedal at cold starup. Once it starts, the driveability is very bad, it hesitates and stumbles until warmed up which it then runs excellent. Oddly, the cold idle is dead steadyand perfect.

So the problem is a lean condition upon acceleration when cold. Have any of the other 3.0 conversions experienced this problem? I have swapped all of the cold start devices and tested them and their is no change and they spec out.

Thanks
jrreeve
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Post by jrreeve » Fri Mar 17, 2006 8:49 am

Need a bit more info. The EFI is still L-Jet right?

Have you checked the fuel pressure at the rail?

Have you touched the AFM potentiameter?

Known good the AAV valve, cold start injector and thermo-time switch, right?

Rob
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dcefali
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Post by dcefali » Fri Mar 17, 2006 11:09 am

It is still l-jet, totally stock, AFM and all. I was not suspecting fuel pressure since it idles perfect, even when cold, and when warmed up drives perfect as well. It's just a cold engine hesitation. But no I have not checked the fuel pressure.

I initially thought I had an AFM problem, so I stuck a screwdriver in the AFM to make sure the fuel pump runs, and it worked like it was supposed to. No other testing though.

I checked the values for the thermo time switch, they were good, and have swapped out the AAV and the cold start injector with spares, no change.

Does the cold start injector keep spraying even after the engine is started and idling? I know a lot of people have done the 3.0 conversion, and am wondering if this is a typical problem.

Doug
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GregoryV
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Post by GregoryV » Fri Jun 02, 2006 10:39 pm

Hi Doug,
Saw your post - don't know if you figured it out by now since it's been two months.

Even with the original 2.5 AFM/throttle body/fuel lines/ you should NOT have any problem with the cold start.

I've had this car for a long time and I do remember some years back experiencing what you describe ... I just can't remember what the fix was.

Not much help but maybe a little!

Gregory
Last edited by GregoryV on Tue Nov 20, 2007 9:17 pm, edited 1 time in total.
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dcefali
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Post by dcefali » Sat Jun 03, 2006 8:17 am

I recently figured it out. I had the thermo time switch connector plugged into the FI temp sensor. They are both on the thermostat housing and have the same exact connector. Technically, they are color coded, but on a 20 yr old motor everything is the same brownish color. Since I switched them, it has run flawlessly.

The real surprise was when I put in a 3.0 AFM and loosened the flap spring a couple of notches. The GTV 6 is so quick now. What a car!

Thanks

Doug
1986 GTV6 3.0
1991 Spider
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