grumpin

Cool! Yes, I get about a 2-300 rpm instant jump. I'm assuming it does too. Not any good info about it. But through trial and error, starting to get an idea of how it works.

FGZ

My hard starts began when the weather got warmer, and they have gotten progressively worse until last week when I couldn't get it running. Plugs were fouled and it was flooded, so drying all that up and cleaning the plugs got me going again, but still hard starts.

Yesterday at lunch I tried grounding the FPU switch like grumpin posted, I've had 3 flawless starts since then. I'll update with longer term results as time goes by, but so far this is a life saver.

So can we talk about what the FPU is doing to flood the motor and why grounding it fixes it? I'm not clear on its intended function. And to be clear, my starting issues this summer have been at an ambient temp of ~60-70deg. Hot starts have been easier but it will still idle low until I blip the throttle.

grumpin

It seems odd to me that you were getting flooding. The way I understand this to work is when warm enough for this switch to make you get more fuel and more RPM. To prevent "vapor lock". You may have another problem also. Cold start injector, O2 sensor. But, if this stops the hard starts and no more flooding, great! I would keep doing what you're doing and see what happens.

FGZ

In my case it seems the FPU is firing every time I startup. So when the motor is at 70 degrees, I get the extra fuel you mentioned. Feathering the throttle a little right when it tries to fire up has helped me keep going for a few weeks, the idea being that I'm supplying a bit more air to help deal with the extra fuel. As time goes on the plugs start to foul and my spark gets weaker which lead to flooding last week.

When I can finally get it running, I'm at ~500 RPM, nearly dying, while I feather the throttle. It clears up once I get the RPM above ~1500 and it runs fine. I haven't completely ruled out any other components, I just started with this one based on ease of modification and once I knew I had good spark which I confirmed during last week's flooding.

RAD4Runner

Thanks for sharing your experiences, guys. And Scope103 for the link to tech bulletin. (just came across this today)
I get hard-starts, too, but rarely and I think it's because of intermittent CSI timer switch. The molding in the housing is loose. Got replacement from Chefyota but haven't installed it, yet.
Cheers!

grumpin

It sounds like how mine acted. Maybe its not flooding. I would keep trying the ground method. Did you install a switch?

grumpin

Cool! These things can be fickle. But seem to keep going.

FGZ

Maybe not a traditional definition of flooding, but that's what it seemed like when I pulled out wet, fouled plugs. The longer I went along with the hard starts, the more the plugs fouled, until finally it just wouldn't start. Oh and I have a very short commute - 3.5 miles doesn't help me much to keep things clean and un-fouled.

Yes I went with a switch. I don't think I'll be turning it off very often.

PO has been into this connector before, I see. So I tied in at the same spot. When I get time I'll solder things up better, I literally just threw it on over lunch trying to help my cause...which is to successfully go home after work without having to bum rides.



The black wire goes from the FPU, through the firewall at a heater control cable (old, loose grommet helped), to this switch under the dash. Other end of the switch is grounded where I saw some other grounds gathered.



Not pretty, but it's working at the moment. I'll try to clean things up at some point, or just pursue a motor swap.

grumpin

I never leave that switch on, just use it when it won't idle for 5-10 seconds. I think something else is wrong. Can't remember, did you check for codes? I'm wondering if your cold start injector is staying on. The FPU is helping, but not a solution.

FGZ

Just checked for codes, nothing but normal operation. I wouldn't be surprised if something else is going on for me, I just know I can't start it easily without grounding that switch. It's only been 3 days so far maybe I'll learn more about it as time goes on

Shagool22

Like Grumpin said, I also never leave the switch on. When I know it's gonna give me a hard start I'll flip it on (to ground) and let it idle for about 15-30 seconds and then turn it off and my idle is up to where it should be.

Tomorrow try this. And see if you get the same results and grumpin and I. If you don't get same results, most likely you've got a different issue.

FGZ

I've done both ways - leaving the switch on all the time and turning it off after cranking. If I "refine" this setup I'll go with a push button that is only grounded while I press the button, that way it's easier to make it just part of the starting procedure until I figure out the real issue.

When starting, I leave the switch on (grounded) before I ever turn the key. Truck starts up fine, idles fine. Then I can leave the switch on or turn it off while I drive, it doesn't seem to make a difference in how it runs. But this morning I turned the switch off ~5 seconds after startup and it made no difference in idle speed or while driving.

Odin

Very interested in this problem as it seems like now that the 90 degree weather has hit my truck is doing the same thing from time to time.

FGZ

It took about a week or 2 to get back to hard starts, regardless of whether I had the FPU grounded. The pattern so far is that they get progressively harder until I get fouled plugs and can't start like I posted 8/5. So before it progressed to the no-starting point, I pulled the plugs again this weekend and found 3 things:

1.) Overall the plugs looked pretty good. Some oil deposits but certainly not fouled.
2.) #4 plug (which I couldn't pull last time) looked great BUT it was gapped way small. It wouldn't fit on the gapper which starts at .020.
3.) With brand new NGK plugs (all at .032 out of the box) it started great again.

So I'm probably chasing some other issue, but I guess I'm stuck with swapping plugs every few weeks until I find out more.

grumpin

Have you checked the Cold Start Injector? 85 FSM has three checks. 2-4 ohms across the connector, spray pattern and one drop per minute (max.) leak check after shutting it off.

FGZ

I haven't. Since I'm getting too much fuel, I'm looking mainly for the leak correct?

grumpin

Yes, You could also disconnect it and check for power after start. There is a timer, but I haven't found any info. on how long it stays on. Can't imagine too long.

grumpin

Here's something else to think about.

http://www.toyota-4runner.org/classi...stic-code.html

AppalachianOffRoader

I had a similar issue plaguing my truck not long ago. After running for a while then shutting down, after startup it would idle extremely low and even died once. It would also do it sometimes on a cold start at a stop sign or stop light after running or approx 5 to 7 minutes.

I changed my coolant temp sensor, my thermostat, and turned my idle adjust screw up literally about a hair, and viola! Runs like a Singer! Give it a shot and see if it fixes yours.

bensyota