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Hard cold start, lean condition at 3000rpm

849 Views 2 Replies 1 Participant Last post by  Eric V. Hansen
So I am stumped,
I have a 94 single turbo with a VPC and AFC, I just had the tranny replaced and the Mechanic killed the gasket from the mid-pipe to the exhaust andit was leaking exhaust gas, enough that I noticed it when we started it, I drove it about 500 miles an then made a gasket from stainless steel and put a mr.gasket material gasket between the two stainless gaskets and sealed it up tight no leak at all. The car ran fine before I made the stainless gaskets and installed them but after I sealed up the exhaust with the new gasket the car on the first start dropped rpm to 500 to 520rpm and then after at cold condition was very hard to start. It will not start when cold I have to crank it for about 2 minutes. then

The second thing I notice is at highway speed (80mph) it runs lean at about 15.8 to 16.1 on the AFR, normally its 14.7 to 15.0. at wide open its nice at 11.6 to 11.8 but under 4K its seems lean.

I have ordered a new O2 sensor and plugs, and a fuel filter.

My thoughts on what it might be is
1. the leak may have cooked the very old O2
2. the fuel filter is getting dirty
3. the fuel pump is getting week in the 6 volt mode and causes a lean condition at cruising speed
4. spark plugs are toast ( I do have a hks dli,don't know if it matters.)

so at this point any advise or recomends would be great. Thanks

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I think I found my problem, one of the wires on the water temp sensor is broken off. I pulled the codes from the car I got #22 (temp sensor) #31 mass air (probally VPC) #42 speed sensor (just had tranny replaced) #47 sub throttle position sensor (???? do know why this came up)

any way I will fix the temp sensor problem and hope it fixes it, i am guessing but I'll bet the IAC works from the signal off the temp sensor hence the low idle.
I'll keep you posted.

chime in if you have any thoughts on the other #47

thanks Eric
problem solved

Code #22 was it water temp sensor. I must have disrupted the wire to the water temp sensor and I had one wire off the connector. I soldered it back on ordered a new connector fot the right fix and took it for a drive and it back to normal, AFR are right where they should be 14.4 to 15.0 starts rightup and its all good.

So if you car is hard to start and your afr's are lean check the codes and then maybe you have a water temp problem.


A.K.A. (The mailman of the mountains)
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