jennygirl

Hi all, I just bought an '87 22re 4runner and I absolutely love it. I've been diagnosing and fixing problems all week successfully, but there is one last remaining issue I have been unable to fix: hard starts.

After much research (and lurking on this site) I suspected the CO relay. I popped the thing out and tested both entry points for the relay with a 9V battery (during start and from AFM) and everything checks out (relay engages just fine on both).

However, I am not getting any voltage through the CO connector's contacts from the starting circuit which means there is something going on before the CO relay and it's not getting there. At first I suspected it might be the ignition switch, but the starter turns over properly. Are there multiple contacts coming out of the ignition switch during start? I.e. one to starter and one to COR? I figure it is just one contact that gets sent everywhere but I am unsure.

I have the '88 4runner FSM but have been unable to locate what I need to be looking for. Any and all help/direction is greatly appreciated!

Also please do not think that just because I am a girl that you have to dumb anything down for me, I have plenty of electrical and mechanical experience and I'm a huge DIY'er. Lay it on me!

Thank you in advance

scope103

The easiest way to check the COR is to jumper FP to B+; this bypasses the COR and runs the fuel pump whenever key-on. If your hard starting goes away, THEN I would suspect the COR. http://www.4crawler.com/4x4/CheapTri...CheckConnector site can help you find the jumper.

At least as of 1993, the COR gets its STA signal FROM the starter relay, so if the starter is turning you SHOULD have power to the COR with the key to start. Remember that signal goes away as soon as you let go of the key; the COR is "maintained" by the VAF.
http://personal.utulsa.edu/~nathan-b...96circuito.pdf

jennygirl

Thanks scope. And yeah, it's actually not the COR I suspect anymore, it's the STA voltage getting to it that is giving me problems.

If I disconnect the COR and test voltage across the connector's STA contacts with key in Start position, I get nothing. Even just checking for continuity I get nothing. Nadda. STA Voltage is not getting to the COR.

I just tested the B+ to Fp jumper, no change which would seem to make sense if the problem is before COR, right?

I've already tested the COR by itself with a 9V and it's good. Applying voltage across STA +/- on the COR and it clicks & checks out great. Continuity is just fine.

The problem has to be before the COR, that is why I'm confused.

The ECU STA is reading voltage during Start position, but not the COR connector. I was thinking I might try to tie the starter to the COR's STA input. Thoughts?

scope103

No change?

With key-on, jumpering FP to B+ should start the fuel pump (I can hear mine standing at the diagnostic terminal; there's no noise from the starter to mask it.) If jumpering does nothing, start by checking that B+ has 12v (battery) to ground, and FP has continuity to ground (FP is through the motor of the fuel pump, but the resistance is almost too low to measure).

If you have no voltage at the STA terminal of the COR, and yet the starter will turn, it almost has to be a bad connection from the starter relay to the COR.

jennygirl

Ok so yesterday for a brief period after removing the IAC and giving it the cue-tip treatment it was starting perfectly and idling up during start and everything.. I was amazed and thought it was fixed!

But then this morning back to the same starting issue.

My next suspicion was the starter because the little plastic clip that holds the solenoid connector is broken off.. I thought this could have lead to arcing and possibly a bad contact. When I unplugged the connection to the solenoid and tried to start sans-starter, I could hear the CO relay clicking when turning the key to the START position. As well, I could hear the fuel pump kicking in.

SOO it appears I need to change the thread title, because it's definitely not the CO relay or some kind of electrical issue. I am relieved by this.

The next thing I am going to check is the cold start injector- my upper intake manifold is gunk MAX and I think it could easily be clogged.

Low idle once it does start is now fixed thanks to cleaning the IAC. Bonus

More updates to come. Thanks for the help, scope, and for the views.

jennygirl

I just bled the pressure in the cold start injector and put dielectric grease on the connector, started up perfectly 3X in a row.

Getting closer, may even be fixed

jennygirl

Still starting up well, all seems good.

jennygirl

Nope not over yet

It's weird: if I bleed the fuel pressure via the cold start injector a little bit, it pops right on every time. What-the-heck

This has to be some sort of fuel issue.

Does the cold start injector even fire if it's 75ºF outside? I don't think so, right?

On another note, I installed my LCE fuel pressure gauge today, so I can see the pressure from the engine bay. I was reading 31psi at idle and 36-37 hitting the throttle. Letting the car sit, it loses about 5psi every hour. I take it that means I have a leak somewhere or the fuel pump is not sealing up properly when not running? Also after coming back from a drive it reads about 20psi. Weird.

So my questions:

1) does the cold start injector play any part during summer in socal? aka is it worth replacing to try to fix this?

2) why does bleeding some of the fuel pressure actually help it start?

3) is it normal to lose some fuel pressure in the lines if the car has been sitting a while?

Thank you

Edit: wanted to add that I recently replaced the fuel filter, so it is not that.

wyoming9

iTrader: (1)

How about you define just what you mean by hard starts??

This can mean different things to different people.

Just what have you done as far as a tune up??

How do the spark plugs look?? Reading plugs can play a part in figuring out these things.

I did note you changed the fuel filter.What about the air filter??

The Cold start injector time switch stays closed to 95 degrees F

Not knowing the LCE fuel pressure gauge I am guessing it is electric and no fuel lines running into the cab.

Are you opening the cold start injector line with the fuel pump on or off??

What does the throttle body look like perhaps in need of a good cleaning ??

Does this only seem to flare up after the engine sits for a period of time or can it occur at any time.

A fuel pump that is old and tired can loose pressure after sitting .there will be a time period till the tired old fuel pump pushes the air through the injectors.

When your cracking the cold start line it bleeds out the air perhaps.

Injectors that have gotten some rust can cause fuel to leak down in the cylinders .Are you getting any fuel in the oil??

I think your sharp enough if you had any external leaks you would have said.

You will get it figured out!!

Could be something as simple as just poor ground cables

jennygirl

Thanks wyoming9, I'll try to answer the best I can

Starter churns for 1-2 sec, followed by 100-250rpm sputters for 1-2 sec, followed by 500rpm idle until revved/warm.

If I depress the gas pedal while starting up, it seems to skirt the issue and the engine has no problem at all, then drops to a suitable 750-900rpm.

In order since buying the car two weeks ago (started up perfectly when I got it)...
• oil change & new oil filter
• spark plugs & wires
• new rotors & pads
• cleaned throttle body (this is around when I started having issues)
• new throttle return spring (old one was worn out, didn't always return to the same idle, fixed)
• checked/cleaned all sensors and applied dielectric grease to connections
• new O2 sensor (not OEM)
• adjusted TPS (took several tries but perfect now)
• cleaned dashpot filter
• adjusted idle screw
• fuel filter
• inspected / tested fuel pump
• cleaned & adjusted IAC
• new vacuum lines
• new PC valve
• topped all fluids


Mods
• battery relocation
• custom intake (relocation w/ K&N filter)
• 2.25" exhaust from headers (car came with headers, not sure which ones)
• LCE fuel pressure gauge
• short shifter
• xenon conversion

I've been a busy girl, still not done!

Todo
+ 2 stage thermostat
+ valve clearance adjustment
+ intake manifold cleaning (tons of caked buildup, ODO is at 489k miles)
+ other stuff

Fairly uniform, no white spots or damage to the ceramic. Dark spots on ceramic (this means rich, right?)

K&N

So does that mean it comes on unless the coolant is 95deg+?

It replaces the banjo fitting on the cold start injector. You can only see it looking into the engine bay.

Only when key in off position

It was caked, and I mean CAKED. Looked like it hadn't been cleaned in 489k miles

Any time, cold (cool) or hot engine.

I think that's a likely cause, the dropping fuel pressure as the car sits would support this

Hmmmm.. Yes totally possible!

How can I check for that? Yikes that does not sound good

Thank you! And yes no external leaks that I have found so far.

Yes definitely, but when I test the voltage under start it stays pretty healthy. 9.5V when the starter churns and if I give it gas it starts up just fine. Still a possibility. Also the solenoid contact on the starter is crap and the connector's snap is broken off.

Let me know if you have any other ideas based on this info. Thank you so much for your input! I really appreciate it, you guys have a great forum here- I really like it a lot!

Edit: also forgot to mention I replaced O2 sensor when I began getting CEL when holding steady throttle on the freeway. That fixed it for about 4-5 days then it came back. Easy to reproduce

Thanks for the help!

wyoming9

iTrader: (1)

First yes the cold start injector will spray fuel any temp below 95 degrees F

Another thing since you only had this two weeks did this sit for a time before you bought it. Have you driven enough to put a tank of fresh fuel through the engine.

Your description of hard staring was very helpful I was thinking you needed to crank the engine over for a minute or two before it starts. Then it spit and sputters for another 5 minutes

I think your very close to figuring it out or you just might be as good as it gets with what your dealing with.

Do you have any history on what this vehicle went through with that many miles.

Maybe you have another thread I missed on just that .

When you cleaned the Throttle body did you replace the gaskets or reuse the old ones.

Depressing the Throttle gives it more air so if your getting to much fuel adding more air allows it to burn better.

You can check for gas in the oil your oil level keeps going up and the oil smells like gas. There was a test but it slips my mind now.

If your going to all the trouble to remove injectors may as well send them out to be cleaned and flow tested.

If the cold start injector is stuck open depending on how much it drips fuel into the manifold could cause your issue .
Even if the electrical is disconnected the fuel line is still attached

jennygirl

Thank you so much for these ideas, I think I'm going to pull the cold start injector tomorrow. I have a feeling it's just absolutely covered in gunk (if it looks anything like the inside of the upper intake manifold). Would it be a bad idea to try to clean it myself with some carb cleaner?

I did not replace the TB gasket (though it did look 100% fine and car runs great once started), but I should have a teflon gasket from LCE arriving sometime next week. At this point removing the TB is such a fast procedure... I must have done it 10 times by now!

So what you're saying is there should be absolutely no change in fuel pressure no matter how long it sits? That makes sense to me, that means there has to be some sort of leak somewhere. I aim to find it somehow.

As far as history of the vehicle, I have nothing. The guy I bought it from was third party selling it for his friend who I was never introduced to. Either way, I am happy to have it regardless and the lift a PO did to it is perfect imo. It was love at first sight for me, almost had a heart attack when I saw the thumbnail & read description on craigslist. Troubleshooting this thing has been one of the most fun projects I've done in a while- even with the startup shenanigans. Learning a ton and loving it! Such a cool car

Very eager to see what the cold start injector looks like. I'll check in with my findings.

Thanks again wyoming, you've supplied me with some great ideas/possible scenarios!

wyoming9

iTrader: (1)

Your quite welcome.

That is a nice looking 4Runner.

I don`t suppose you can weld??

If you can I am glad your about 3000 miles away.

scope103

according to the manual, the CSI timer opens at around 86°. http://personal.utulsa.edu/~nathan-b...ne/39colds.pdf But I doubt that's your problem; it only opens with the key on STArt. But you could disconnect the electrical connector to the CSI as a very easy check. It won't catch a drippy injector (as wyoming9 says).

You might have a leaky injector (mentioned by wyoming9). That would allow the fuel pressure to slowly drop, and it would cause the truck to be very rich (at startup) until the excess fuel was blown out. (It would not explain how bleeding the fuel pressure at the CSI helps; that's a mystery.)

I don't think looking for gas in the oil will help; unless you've got a LOT of gas in the oil it will evaporate as soon as the engine warms up. Also, a leaky injector could leave the fuel on top of a well-sealed piston. (OR, the CSI could be leaking.)

I'm not sure how to accurately diagnose a leaky injector, but I'd try turning the key until it first fires then stop. Quickly pull the plugs to see if one (or all) of them is wet. A wet plug is on an over-rich cylinder, and it could have a leaky injector.

jennygirl

Thanks and yes, I have been welding for years. Mostly migging steel. Why, are you afraid I'm going to detonate myself with that leaky injector??

And thanks scope I will keep all that in mind when I try to hunt down this leak/pressure loss. I have also read that the fuel pump inner seals could be going bad and letting the pressure back into the gas tank... which would not be so much of a problem I suppose.

I tend to think it is a leak somewhere though

Thanks for your re-input! I'm just getting up so I'll check back in a bit after I have poked around for a bit.

A leaky injector does sound likely. Especially with how gunked the intake manifold is. I'm thinking there's got to be a way some of that gunk found it's way into an injector and is keeping it open.

scope103

The gunked up manifold seems to be an issue when it starts blocking ports, notably the EGR input. It's bad, it should be cleaned, but I don't think it's your problem. Gunk in the intake goes "by" the injectors, not through them. But if you have a leaky injector, you don't care what caused it, just how to fix it.

You might consider running a can of injector cleaner through your fuel system. It's not really intended to cure big problems, but maybe yours isn't that big. It's a lot easier than removing injectors, and it probably can't hurt.

jennygirl

That's a good idea, I actually picked some up the other day just haven't filled up since getting it.

I'll definitely do that. Thanks for reminding me.

vital22re

iTrader: (2)

Helped a buddy out with his hard start. Turned out to be a leaking head gasket. New head gasket and it started up nice and easy.

Terrys87

iTrader: (1)

I wish more women would get involved in this hobby. Great to see what you have accomplished so far. I got the wife helping me some and that helps out a lot. Are all your vacuum lines routed correctly? I seen you replaced them. I had a tough issue with hard to start and it was one vacuum line I had hooked up wrong. The EGR does make a mess of things and it is a good idea to give the Plenum and all ports a good cleaning.

Is the Fuel Pressure Regulator good and is the correct vacuum hose connected to it properly. On an 87, I think it goes from the FRP up to the rear VSV switch. That is one I have had issues with if not hooked up correctly.

jennygirl

Thanks Terry that's really nice of you to say And actually I did have some of them hooked up wrong early on after the intake install (the group of three on top of the TB), it lead to some misfiring and crappy throttle response. I was so mega-bummed that I had messed something up. That is when I was adjusting TPS like crazy thinking that was the problem! I even popped the top of my AFM to make sure the potentiometer surface wasn't dirty/damaged. Then I decided to double check the vacuum hoses by looking at some pics and it was a huge "ah HA!" moment. Boom engine ran better than ever.

I did just replace all my vacuum lines, but I did them one by one as to not get any messed up this time

I found a few vacuum hoses that were cracked and one that was blocked.. I think it was the EGR hose. I was twist pinching it and all sorts of peppery looking crap was falling out. Yuck!!!

I spent yesterday installing new speakers and diy style amplifier board, so I haven't made any progress on the hard starts since the last time I posted here. Today it is HOT here in LA so I am taking a bit of a breather at the moment.

Thanks for changing the thread title, btw. Much more appropriate. Cheers!

vital- my roommate just picked up a compression test kit so I think when my engine cools down a bit (just got back from a drive) I'm going to test the compression in addition to checking the CSI. Car is still starting up 100% great every time as long as I have my foot on the gas while turning the key.

I'm also going to install a hidden fuel pump kill switch to thwart car thieves. Last night I went to an art show with some friends in a sketchy part of town and I was an anxiety ridden mess. It's great working on cars so much like this, but it raises the stakes of how much we care if someone were to steal it. Better safe than sorry.