high RPM on cold start(solved)

gto66_455 · Post by **gto66_455** » Thu Oct 26, 2017 1:55 pm

I am having a problem with my cold start. The first time I attempt to start my rpm's go to 2100 and my afr is 18. When I turn off the key and try the second time my rpm is still 2100 but the afr is 14 and the car will start. I think there is something wrong with the rpm reading during cranking, it seems to be ok while running
I have MS2 3.0 with 3.4.2 firmware

tryingbe · Post by **tryingbe** » Thu Oct 26, 2017 3:16 pm

Big V8.

What valve are you using for idle control?
What wideband are you using?

gto66_455 · Post by **gto66_455** » Thu Oct 26, 2017 5:02 pm

455 pontiac
I have a four wire stepper.
AEM wide band

Matt Cramer · Post by **Matt Cramer** » Mon Oct 30, 2017 7:17 am

I see you're controlling ignition. What sort of distributor pick up are you using?

gto66_455 · Post by **gto66_455** » Mon Oct 30, 2017 4:32 pm

It is a MSD ready to run distributor with three wires out, red power, orange signal and black ground. I believe it is a VR pick up. Also has a gray tach signal wire.

Matt Cramer · Post by **Matt Cramer** » Tue Oct 31, 2017 5:53 am

How exactly is that wired up?

rickb794 · Post by **rickb794** » Tue Oct 31, 2017 11:06 am

gto66_455 wrote:It is a MSD ready to run distributor with three wires out, red power, orange signal and black ground. I believe it is a VR pick up. Also has a gray tach signal wire.

If it is a powered sensor it is not likely a VR (unless the distributor has a high current coil driver built in).

gto66_455 · Post by **gto66_455** » Tue Oct 31, 2017 2:21 pm

I figured out the problem. When I originally wired my relays I had only wired the fuel pump to the FP relay, and everything else to the other relay. In the manual it shows that the fuel pump, injectors, coil and o2 sensor get power from the fuel pump relay, the dist and ecu get power from the other relay. When I rewired the relays my cranking rpm was where it should be, about 200 rpm.

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high RPM on cold start(solved)

high RPM on cold start(solved)

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Re: high RPM on cold start{solved}