andykrow

Hey All,

Hoping for a little advice here. I've searched a bit but sort of need to know where to proceed from here.

My truck (88 22re 5spd) recently began having "warm" start problems. It would start beautifully and instantly when cold in the morning, and beautifully within an hour or so of running ("hot" start) But when I would try to start it after work (on the 80 degree days we've been having) it would start really rough, usually requiring gas from the pedal to finally get going and then a few revs to get it to hold the idle without stalling.

First check I did was to jumper the fuel pump but this helped nothing.

I then disconnected the cold start injector and voila! She starts perfect when "warm." Of course, now she hates the cold CO mornings but that's expected.

So it seems clear after a few days of running without the CSI that this was the issue, but why was it firing on every start regardless of temp? I have read that the coolant sensor can be faulty and cause the ecu to think a cold start is always happening. Is this the first place to start? What else could cause this? The truck runs the same as before once it's started so I don't think the CSI was constantly on.

Also, regarding the ECT, is it safe to buy one from napa? I can't seem to find an oem part anywhere.

Thanks for any help you can give!

thook

Seems to me, possibly, it could be the coolant sensor. Without the added fuel of the CSI system, the more than adequate amount of fuel injected by a potentially faulty coolant sensor is not a problem with warm starts. Go ahead and test it. But, seems if the sensor were faulty, you'd also have driveability issues and problems starting after a period of hot soak, as well. I'll have to think on this one a bit.

Maybe your idle air valve is sticking?

andykrow

Another symptom I have is no difference in idle speed no matter what the outside temp is, nor if it's a cold or hot start.

Doesn't the ect have an effect on whether or not the csi is used?

Would a sticky idle air valve give me other issues? My idle is solid and smooth. Can that just be cleaned up? (I know it isn't cheap...)

I appreciate your thoughts on this, thook! Thank you.

thook

Okay, thanks for giving some more detail. Helps me help you much mo' better.

No difference in idle speed? Would you consider the idle speed to be low or high, or just normal and remains there? At what RPM's does it idle, if you have any way to guage that? In any case, that's fairly indicative of a malfunctioning idle air valve. However....

A sticky idle air valve usually does give a rough idle depending on the conditions. If it's cold outside and the valve will not open, typically the motor will have trouble idling. This is because a considerable amount of fuel is injected to rapidly warm the motor. If there's not enough supplementary air via the idle valve, then the air/fuel ratio will be greatly out of balance; too rich. If it's warm and the valve is open, there's too much air as less fuel is needed to warm the motor; so, too lean. But, this is only what's typical, I suppose. Maybe yours is sticking somewhere in the middle.

If your idle is solid and smooth in any condition (????), then you certainly don't have a coolant sensor problem. Whatever it is giving you a fit, it's somewhat less of a critical component, relatively speaking. But, given everything your stating about the situation this could be a combination of factors.

I'd start by testing the time switch and the idle air valve. The time switch because by disabling the cold start you didn't have starting issues unless it was cold. And, the idle valve because you're not getting a warm up idle cycle. If those pass, then move on to other potentials.

I believe for your purposes the specifications in this manual will apply to your vehicle. Changes to voltage/resistance specs on the time switch, for one, were made during your year of vehicle and, I believe, continued on:

http://personal.utulsa.edu/~nathan-b...sm/engine.html

Unless you have the remote style auxliary air valve, the test given for your idle valve will work for sure.

andykrow

Thanks for the info.

Just out of curiosity where should the idle be during the warmup cycle. I have an aftermarket tach which seems to be fairly accurate, and I have the rpms set for roughly 800. And I should say my idle is mostly stable, day by day. Sometimes in the morning it will sit around 900-1000, but by the time the truck is good and warm it's back to 800. No fluctuation in the idle as it sits there running. So maybe my warmup cycle is sort of working some of the time?

You're description of the sensor is leading me to think that thing is okay. The truck drives great - tons of power and no weird rich smells or anything. This morning was 55 degrees, which was cold enough that the truck wants the csi, but once it started it idled fine.

I'll see where the time switch and idle air valve lead me...

andykrow

thook I'm a little confused about how to do the on vehicle check. It says when cold and you adjust the idle speed screw in, the idle speed will drop. When warm the idle speed should drop below the idle speed stop. Huh? Does this mean when cold you can't kill the engine with the idle speed screw but when warm you can?

BajaRunner

Test the resistance of the ECT at cold temp and warm temp to make sure they are in spec.

If you've never cleaned the idle air control valve, I'd just take off the TB, then remove the IACV right beneath it and spray the valve out a few times with carb cleaner. Every Toyota truck I've owned needed cleaning of the IACV for proper idle.

Both are easy and if it doesn't help move on to the next...

andykrow

Well I'm doing the drum brakes first today and then digging into this stuff.

The more I think about it this seems like a time switch issue, since disconnecting the csi stops the warm start issue, and then the idle air valve is probably a problem too....though that doesn't bug me so much.

thook

thook

Well, what your adjusting during the test is the idle bypass valve. IOW's, this is an air bypass for the throttle valve.

At idle, the throttle valve/plate is only open a smidge. So, the only other way for air to enter the intake is through the bypass. That is when the vehicle is warm. When cold, of course, you have the idle air valve to supply the extra needed for warm up. Also known as "auxiliary air valve". So, what you're doing is testing the engine operation against available air.

Since the IAV is supposed to close when the engine is idling at operating temp, if you were to close off the only other available source of air via the idle bypass, the engine theoretically will not have enough air to keep it running. I say theoretically because the amount of clearance of the throttle plate will affect the result. If it were out of adjustment, ie too far open, this will affect your testing. But, if it's in adjustment, the engine should die when you close the idle bypass IF the IAV is closing fully. If the engine doesn't die, and you've not dinkered with the throttle valve at all, then the IAV is not closing fully.

And, yes, when the motor's cold since the IAV is suppose to be open, the engine will still have enough air to run even by closing the bypass valve.

andykrow

Yeah sorry about that! Heh heh. I don't know why that had slipped my mind before... I guess I had been thinking more that it doesn't fluctuate in front of my eyes.

So idle warmup is really only a slight boost. For some reason I was thinking it would be more up in the 1500 range... And last time I looked into the throttle body it needed a cleaning, so it's probably a safe bet the valve could use some throttle body cleaner too.

back to the drums! (really wanting to do a disk brake conversion back there right now...)

andykrow

thanks too on the testing tip. that's what I suspected after looking at the diagram...

thook

Just be careful to protect the throttle sensor however you can when cleaning the TB. Don't want any solvents bleeding into the circuitry. Ideally, you should remove it, but that's kind of a pain, I know.

1500rpm range would be considered too high, although it's not really detrimental. You'd use more gas until it warms up and the valve closed, but it'd be more of a problem if the valve didn't close and the idle remained high no matter the condition. 1k -1200 is ideal. Of course, the higher the cold idle RPM, the faster the engine warms, so there ya go.

thook

Schmart man.....

humboldtMUD

thanks for that info thook, looks like im the the same boat as andy. going to get that iav off once this dangd rain quits(almost made it).

humboldtMUD

so i dont want to hord in on andys thread...maybe will help him too but i checked the resistance of the heat coil and got somthing like 7milli ohms(book says between 39-59).somthing between the heat coil and the connector is bad,or bad coil.

thook

I'll get with you tomorrow, man. I'm off for the night....

1990yota-pickup

i belive iam starting to slowly get some of these problems with starting..

cold morning first start, truck will start befor the bendix has disengaged from the flywheel, (were talking not even a half of a crank)

but during the day, it well take a 2-3 cycles to get it to start.. maybe a slight touch of the gas pedal

humboldtMUD

starts like a jeep warm eh? mine will start rev to 1200 and die if no throttle

1990yota-pickup

i have no idle issues, when its in high idle just after starting it then i settles down to around 800 or so..