Thermo Time Switch for '87 5ktq? [was Fuel Pressure Testing - 5ktq - where to tap?]

[Ben Swann]

On Thursday, April 11, 2002 3:14 PM, Bernard Littau [SMTP:bernardl at acumenassociates.com] wrote:
> > > I have been trying to track down the cause of poor cold start problem...
>
> Hi Ben,
>
> I don't think fuel pressure is likely as the problem.  I had low fuel
> pressure, and the car started fine -- it had problems at high load due to
> low fuel pressure.  Likewise, your fuel delivery capacity is likely not the
> cause -- there should be plenty of fuel to idle the car coming into the CIS.
> For the fuel pressure stuff see:
> http://www.sjmautotechnik.com/ficis.html#fuelp

Yeah, I got the guages hooked up, and so far don't see anything out of spec.

I have not done warmup tests, only cold with fuel pump running, engine off.

System Pressure = 88-90 PSI
Control Pressure = 30 PSI
Ambient Temp = 67 degrees
Leakdown test in progress SFSG

>
> I think the problem may still be the Cold Start Valve not squirting.  This
> could be due to bad valve or bad thermo sensors.  The multifunction and the
> ECU temp are possible problems, the intake air sensor is not likely.  I
> don't think the intake air sensor is even used below 1800 rpm or 0.8 bar
> MAP.  The fact that you get 1.4 bar makes me think your thermo sensors are
> OK.  Worth checking anyway :-)
> See:
> http://www.sjmautotechnik.com/10vcoolt.html
>
> Use the fuel pump relay fuse tests to cycle the Cold Start Valve and make
> sure it is squirting under the control of the ECU.  See:
> http://www.sjmautotechnik.com/ecuf.html#out1
> specifically, test#4.

Right - did that a couple of days ago - just fine, 10 spritzes in 10 sec @ 1/sec.

>
> If it passes test#4, you may want to pull out the Cold Start Valve and make
> sure it is squirting when the engine is cold.

Have not done that.

>
> Good luck,
>
> Bernard Littau
> Woodinville, WA
> '88 5ktq
>