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clacey

5 Secs To Start In Morning

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I have a 91 LS400 with 213,000mi. It takes about 5 secs to start in the morning. After that, it cranks immediately. I have done a tune up (plugs, o2 sensors, distributor caps & rotors, as well as injector cleaner) but it didn't help. The exhaust smells as if it could be running a bit rich with a slight amount of white smoke from the exhaust even after it is warmed up. Fuel economy is not so good. Other than that I seems to run really well. The idle is steady. Sounds good.

Any Ideas?

Could it be the cold start injector? If so how can I test? Where is it?

Thanks,

CL

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Recently, I just replace my rotor caps, distributor caps, pcv-valve, and Sparkplug wires. I had a white smoke comes out at first then I reseted the ECU, now my idling is at 1000 rpm at first startup and the car runs steady too. I don't know this is a good sign or bad.

Have you reset your battery yet? Try to do that, let it disconnect for at least for 15 mins then reconnect it and see it makes any different?

My previous problem was cylinder #2 and #7 missfiring due to water got in there. Engine light was on and also traction light, I went to Autozone and check they told me that p0302 and p0307 was missfiring. I went ahead any replace sparkplug#2 and 7, also reset the ECU because I thought the car was not smart enough to know itself.

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It probably is the cold start injector

regular fuel flush is usually not enough as it is not concentrated enough to do any good as the injector is only used for a short period of time before turning off.

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Thanks for the replies. I wish there was a test to see if it is the cold start injector or the cold start module.

I did the CPU reset but nothing changed. The only thing I can think is it must be the cold start system malfunctioning. I dunno.

Is there a way to check it?

Thanks,

CL

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:ph34r: White smoke when start up could be a sign of Power Steering being sucked in to the intake due to a bad pressure valve by the power steering Pump ( back bottom ) I have the same slowness at early start up. have not yet replaced the wire set. I fix the smoke problem by fixing the valve :ph34r:

:cheers:

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I have had the same problem with slow starting for the past year. The cold start module's (called the Start Injector Time Switch in the manual) resisitance should be 25 - 45 ohms below 59F and 65 -85 ohms above 86 F. This item is below the RH ignition coil next to the thermostat housing.

My switch tested fine so my cold start injector is probably plugged. To remove the injector, the manual says to remove the air cleaner, AFM, throttle body, LH engine cover, disconnect ISC valve conn, cold start injector connector, VSV connectors for EGR and FPU, disconnect 18 hoses, remove EGR modulator and VCV, remove air pipe and vacuum pipe , disconnect #3 water bypass valve, remove accelerator cable bracket, disconnect cold start injector tube, disconnect EGR pipe, remove air intake chamber and finally the cold start injector.

I was wondering why I haven't tackled this task sooner.

Once I get the injector out I plan to clean it by running some solvent through while having the injector powered by a flashlight battery. The manual shows a test using the 12 volt car battery across the injector terminals but says to be quick. You need to be careful since there is a coil in the injector you can create an arc by opening the circuit which could ignite any spilled solvent.

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Interesting Modman. I would be interested in reading more about how you would perform this task with a flash light battery.

Thanks.

CL

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I used a couple of quick connect terminals similar to this one installed on some small guage wire (18 - 22 AWG) to connect to the injector. The other end of each wire were soldered to the ends of a 1 1/2 volt flashlight battery (probably any AAA through D size would work). When you connect the second terminal to the injector you should hear a click.

I then use some fuel line hose which fits snugly over the injector inlet, fill the hose up with solvent, and then use compressed air on the hose to move the solvent through the injector. The compressed air pressure should be low enough not to blow the hoses off. Repeat the procedure until you are satisfied with the spray pattern.

Again, if you pull off a terminal while the injector is powered there will be a small arc (since V=L*di/dt) which could ignite any nearby solvent, so be sure your injector connections are secure.

This procedure worked well on my BMW injectors and should work with the Lexus cold start injector. The factory manual shows a similar setup for testing the cold start injector, only Lexus calls out SST numbers for the injector/fuel line connectors, and then uses the 12 volt car battery to momentarily power the injector.

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Well.... I did it. I thought I'd let you all know the out come.

I cleaned the cold start injector over the weekend. It wasn't faulty, just clogged. When I removed it from the intake, I found that it was COMPLETELY gunked up along with everything else in the intake. I used a complete large can of gumout and a few rags that I scrubbed the intake out with. Since I had it all out, I decided to remove the EGR Vaccum stuff from the side of the intake to make sure it was clean. What a great move that was. There is a pipe that goes half way into the intake. It was completely clogged up with hard black stuff. I had to punch it out with a screwdriver. Remove the silver piece where the vaccum stuff connects to the intake as well as the black valve. It was pretty obvious that mine hadn't been cleaned in 13 years and 213,000 mi. After cleaning off the cold start injector, I did the test from the manual and a perfet cone of fuel came out both sides.

Since you will have it (intake)removed, I definately suggest doing this or at least checking it. It's a great time to really scrub everything out.

I also was able to fix a cracked EGR pipe in under 3 hours. I'll talk about that in a seperate post.

It didn't completely fix the issue but it did make it better. I suspect I'll find that is actually caused by several different small things combined together. I'll be checking for vaccum leaks next.

I hope this helps.

CL

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How long did it take you to get the cold start injector off? I started looking at doing it today but couldn't go through with it.

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It took about 30-45 min. The whole process took about 3 hrs but most of that was cleaning. My fuel economy has really gone way up. Which is a good thing since the cost super unleaded is like buying jet fuel these days. My fuel exonomy was way down to about 12 mpg if I were to guess. I'm going to test everything else that the book says test over the weekend. Since the EGR system was essentially clogged, I need to check the valve to see if it is operating correctly. I also suspect that my #5 & 7 valves are off as well (tapping). I need to change a couple of valve cover gaskets so I'll check those valves (adjust if needed) and clean that out before too long as well.

This repair was definately worth the time as well as the $5.00 spent on spray cleaner and shop rags.

I'll update the post as I do things and let everyone know what helps.

CL

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I don't think that there is a major issue. They might be just sticking a little (judging by the gunky condition of the intake) but I hear that #5 & #7 are prone to need some shimming with time and mileage. It's not really loud I'm just being anal. If I were not going to replace the valve cover gaskets, I probably wouldn't worry about it.

CL

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Am curious where the 'cold start injector' is located on a LS---I know what they are[ have had Bosch systems for years]; but I cannot find them in the service manuals [MFI sect. esp.]; cannot find the name even mentioned anywhere.

I DO NOT have any problem; but if they exist , why is there NO reference to them. I can't imagine what is being cleaned when someone cleans the cold start injector. :huh:

Can someone 'enlighten' me so I can stop thinking about this.

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The cold start injector is attached into the under side of the intake assembly. You can see it by opening the throttle and looking into the intake. it looks like a 2" long 1/4 " rod comming up from the bottom of the housing. It sprays fuel in two directions (front and back) to add extra fuel upon cold startup. It should spray 2 perfect cones of fuel and not leak when it is disengaged.

Now go forth and be enlightened. :D

CL

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