'90 4Runner not restarting when warm???

[Namaste1978]

Hi, I've been having problems with my truck not restarting when warmed up. It starts OK in the morning or after sitting for a few hours but if I try to restart it after a quick stop, it hesitates and I have to hit the gas to get it to start. It's a 90 V-6 3VZ Auto 4wd. It has new plugs, wires, cap rotor and fuel filter. I've been told it can be leaky or defective fuel injectors or a bad Cold Start Injector? Any ideas? Also, does anyone know who is the cheapest place to take it to to get the codes ran and what new injectors would cost to replace? Thanks,Shawn

[forest_grump]

Originally Posted by Namaste1978

Hi, I've been having problems with my truck not restarting when warmed up. It starts OK in the morning or after sitting for a few hours but if I try to restart it after a quick stop, it hesitates and I have to hit the gas to get it to start. It's a 90 V-6 3VZ Auto 4wd. It has new plugs, wires, cap rotor and fuel filter. I've been told it can be leaky or defective fuel injectors or a bad Cold Start Injector? Any ideas? Also, does anyone know who is the cheapest place to take it to to get the codes ran and what new injectors would cost to replace? Thanks,Shawn

Even though you have new plugs ....take a sparkplug out (any sparkplug)first and make sure it is not fouled..if plug is not fouled(black) then remove hose from throttle body and spray some wd-40 or carb cleaner on a rag,open throttle to wide open by hand or have a friend hold gas pedal down inside truck and clean inside of throttle chamber where plate closes(do not try to spray it away or spray inside of throttle chamber)reassemble and start up.

Goodluck and repost here with results.

[Namaste1978]

Originally Posted by forest_grump

Even though you have new plugs ....take a sparkplug out (any sparkplug)first and make sure it is not fouled..if plug is not fouled(black) then remove hose from throttle body and spray some wd-40 or carb cleaner on a rag,open throttle to wide open by hand or have a friend hold gas pedal down inside truck and clean inside of throttle chamber where plate closes(do not try to spray it away or spray inside of throttle chamber)reassemble and start up.

Goodluck and repost here with results.

Hey, thanks for the info but I made sure to do that when I had the intake hoses out for the plug removal and instalation. I cleaned out the throttle body and butterfly with CRC Air Intake cleaner. It didn't make much difference even though the area seemed to have some buildup.......
S

[forest_grump]

Originally Posted by Namaste1978

Hey, thanks for the info but I made sure to do that when I had the intake hoses out for the plug removal and instalation. I cleaned out the throttle body and butterfly with CRC Air Intake cleaner. It didn't make much difference even though the area seemed to have some buildup.......
S

Did you pull out a plug and check to see if fouled...(yes know they are new but if your engine is running too rich it will show on plugs) were old plugs fouled black?
Fouled plugs which are black due to enrichened fuel to air ratio often will start in a cold motor but not after it has warmed up unless you wait a few hours.....need to know what color plugs are,white insulators around middle *post* inside sparkplugs to a light brown color shows good fuel to air mixture ratio.

[forest_grump]

Might try this as well...next time it won't start,unplug your TPS and see if it starts up.

[Namaste1978]

Originally Posted by forest_grump

Might try this as well...next time it won't start,unplug your TPS and see if it starts up.

Hey, I'll pull a plug and check it out. I just replaced them yesterday. Will that be enough time for the deposits to build up on them. When I pulled the old plugs, they were black and suity looking. I've attatched a photo. Is this the TPS? What will unplugging it do? Thanks!

[Namaste1978]

So I just ran out and pulled a plug from the drivers side. Here's a pic. There is some oil around the threads and down where that washer sits. I also unplugged the TPS (If that's what is shown in the pic above.) I unplugged that and nothing different happened. Not sure if I mentioned this but to get it to start when it's warm, I have to hold the gas pedal down for a few seconds (like 10 or so). It will not start without doing that......
Shawn

[forest_grump]

Originally Posted by Namaste1978

So I just ran out and pulled a plug from the drivers side. Here's a pic. There is some oil around the threads and down where that washer sits. I also unplugged the TPS (If that's what is shown in the pic above.) I unplugged that and nothing different happened. Not sure if I mentioned this but to get it to start when it's warm, I have to hold the gas pedal down for a few seconds (like 10 or so). It will not start without doing that......
Shawn

GREAT job of taking and posting pics...a pic is truely worth a thousands words sometimes lol.....dry black fouled plugs are tell tell signs of an over rich fuel mixture and will cause problems like yours but going by photo yours are very clean(maybe a bit too clean if you have more than a few hours on them) so just for kicks lets go the other way...you said it will not start unless you hold gas down and crank for 10 seconds...next time when cold just turn key on til dash lights come on and after 3-4 seconds turn key all the way to off position and back to where dash lights come on and wait for another 3-4 seconds..do this several times and try to start(this will allow the fuel pump to cycle and build fuel pressure in line so your injectors have full pressure waiting before you crank it over)if it doesn't start within a few seconds of cranking....walk away from it for an hour and take airfilter out and pour about 1/4 cup (2 ounces) of gas on it and reinstall and start it up.


This is just to find out if it is a prestart fuel pressure in line problem or a cold start injector problem(only because of you saying it is also hard to start cold as well and you may have two seperate problems related....doesn't hurt to cover all bases and easy enough to check..

Are you driving it daily?If so recheck plug color after a few days driving also...goodluck and will check back

[forest_grump]

Originally Posted by Namaste1978

Hey, I'll pull a plug and check it out. I just replaced them yesterday. Will that be enough time for the deposits to build up on them. When I pulled the old plugs, they were black and suity looking. I've attatched a photo. Is this the TPS? What will unplugging it do? Thanks!

Yes that is TPS.Great pic

[forest_grump]

By the way you will also need to thoroughly check for any and all vacum leaks(don't forget to check brake booster check valve) you may have as a major vacum leak can cause some very weird problems driving but also on startup if severe enough...

[Namaste1978]

Hey Forest Grump,
So I tried the turning the key trick, it didn't make any difference. I'll try the gas on the air filter thing tomorrow. Yes I do drive it everyday. Tonight after the truck sat from 1pm until 9, I turned the key (once) like normal and it started up without any hesitation, didn't have to hit the gas. That's the first time it's done that in a long time. I haven't changed anything though since yesterday. I'll try it again in the morning and I'll try the gas trick on my lunch hour and get back to ya. Thanks again....So I'm a newbie to most of this so how does one go about checking for vacum leaks and the brake booster check valve? Shawn

[forest_grump]

Best way to check for vacum lines leaking is to *pinch* off air flow through them at intake ports with a pair of needlenose pliars and see if idle and pitch(sound) of motor changes ////////////this will break/shatter old hardened vacum lines\\\\\\\\\\\\\\ if it changes then you have a leak..same test for checking brake booster check valve...pinch off vacum line before it goes into check valve at end of rubber hose as it pops into booster.

!!!!!!WARNING!!!!!!!//////////Do not pinch together the steel tube inside of hose that vacum line slides onto.\\\\\\\\\\\\\\\!!!!!!WARNING!!!!!!