Cressida starting problems, same engine as Supra???

[ghillegas]

I have a 91 Cressida. Starts fine when engine is cold. Starts fine when engine is hot, but after it sits for 10 minutes or longer when hot, it offers problems. It will start, but dies, it pings and makes a racket, I rev it high rpms, seems to do better. It will have to be started several times, may take two + minutes to settle down. May not be as problematic with premium gas, but still has problems.

Local dealership checked the computer, did not find anything. Suggested possible leaking fuel injector. Leaking fuel injector would not be worth fixing, even if that is was the problem. I replaced the fuel pressure regulator, no help.

Any thoughts?

Thanks,

Greg

[bgrieger]

You might try having the injectors checked. It's really not all that expensive or problematic to do, though I wouldn't have it done at Toyota.

Some have found the problem to be with the cold start injector time switch. If it has failed, it will dump fuel into the engine even when it's warm. Check the injector itself. It will either be right up top on the intake manifold, or on the underside of the intake manifold - Cressida manifolds are different from GE powered Supras so it could be in either spot. It will have a two wire electrical connector you should be able to see looking down from the strut tower if it is under the manifold. It should have 2-4ohm resistance. The time switch is the top most sensor on the thermostat housing. The resistance on the 2 wires here should be: below 59 degrees F - 25-45 ohm. Above 86 degrees F - 65-85 ohm. The last test is harder to describe - the connector on the switch is offset toward one side when you look at it from above. If you were to look at it with the side the connector is closest to being pointed away from you, pin STA is the left pin. STA to ground should have a resistance of 25-85 ohm. If any of these is out of spec, replace the switch.

Hope that helps.

Bob

[ghillegas]

Thanks for your help. I checked the switch, from the best I could understand the switch is good. I did not check the cold start injector yet. It is a little more challenging for me to get to, but I located it.

I could understand a faulty switch causing the problem. Would a faulty cold start injector cause this problem? Bearing in mind, it happens with a hot engine, after sitting for 15+ minutes, maybe less if it is really hot outside. Would not a faulty cold start injector cause problems other times???

I intend on selling this car, $1000-$1500, 120,000 + miles, I do not think it wise to put much time or money in it.

Is is possible to conclude, it is a leaking fuel injector with certainity, just be the description of the problem?

Thanks,

Greg

Thanks for your help and any insight?

[bgrieger]

If it is leaking, when it's cold and supposed to inject fuel, it's going to appear to be working right...the engine needed that fuel. The TCCS can compensate when running, but it might still be a little rich all the time if there is a leak. On a hot restart though, the ECU is not expecting any additional fuel to be there, and the excess fuel may be too much to get it running smoothly, so it dies before it gets to a steady state when the ECU can properly compensate. I haven't looked at the specs as to how it precisely works on a hot restart, but I'll flip through the manual over the next couple of days when I get a chance.

You might just try to unplug the injector and see if that helps...