Need Help - Girlfriend's Stalling '90 4Runner

[BreckenridgeCruiser]

Hey All,

I am having some difficulty with my girlfriend's 1990 4Runner with the V6 and auto. I have owned some carbureted 40s and 60s and a few Toyota diesels (2B, 3B and now a 1HZ) but am new to both the 4runner/truck platform and EFI systems. That said, I pre-apologize for my lack of knowledge.

So, her truck is having difficulty when it is cold out. The truck will start and idle fine most warm days and will drive fine once at operating temperature. When cold (outside especially) the truck will stall when shifted from park to R or D. Sometimes it will stutter and even stall when you hit the gas moderately hard as well like when you are at a stop sign and want to cross a street quickly. This can happen both when cold and warm, but more often when it's cold outside.

I recently did a tune up (plugs, wires, cap, rotor) and ran a can of BG44K through the fuel system to no avail. It runs better now, but the problem persists. I also want to replace the fuel filter in case it is clogged this weekend, but am not sure where to look for it... In the EPC it does not show its location on the truck.

So, where do I start to try to fix this issue?

Thank you in advance!

Kraig

 

[KLF]

Changing the fuel filter is a good idea, if hasn't been done in a long time. I'm not 100% sure on the autos, but if it's the same as the 5-speeds, the filter is on inside of the frame rail, passenger side, above the trans/transfer crossmember where it bolts to the frame. Kinda hard to reach with the crossmember in place, you will need at least a 14 & 17mm flare wrench, maybe a 19mm, and a 12mm socket to get it off the frame (break the lines free first). Be prepared to take a bath in gasoline when you break the first fitting loose. Give it a good soaking with PB Blaster or other rust penetrant for a day or so.

How many miles? Have the injectors ever been cleaned?

Has the throttle body been cleaned recently?

Cleaned the cold start injector?

Checked the adjustment on the TPS?

Checked the EFI ECU for any codes?

 

[BreckenridgeCruiser]

Fuel filter is the next thing...

I haven't messed with anything else really besides spraying some carb cleaner into the intake. How hard is it to clean the fuel injectors?

There have been no CELs but I will try to check for codes this week.

 

[SunTzuMD]

Make sure there isn't a leak on the intake from the air filter to the throttle body. My 3VZE will barely run if there is a leak there.

 

[vipergrhd]

Boot

I would check the air intake boot going to the throttle body for a split causing some of the symptoms you mentioned.

 

[BreckenridgeCruiser]

Can it really be that simple? Does that happen due to a bad reading at the AFM/AVM.

Does one need to have the injectors leaned at a shop or can it be done by myself?

 

[KLF]

Yes, it can be something as simple as a cracked intake tube. Check the easy/free stuff first.

You need a bench flow tester to clean and flow test the injectors. It's too cheap to try to do this yourself, not worth the risk, they are $$$ to replace if you mess them up. $16 per injector at Mr Injector:

http://www.mrinjector.us/

I've used him and his service is prompt and excellent.