Topic: 22re hard start and surging idle

[Carolina82]

Just picked up a nice 1988 4runner, 22re, 5spd, 221K miles. I'm having 2 issues and can't seem to make any progress.   

First issue. With the engine cold the truck will start fine everytime.  If I drive it to operating temp and switch it off, let it sit for roughly 10-15 mins and try to start it back up it will turn over for 10 seconds or so before it starts. 

Second issue.  Truck has a intermittent surge.  I can get it to surge when I pump the brakes and when I let off it will go back to normal idle.  Truck had random surge when pulling into gas station for roughly 15 seconds or so.   

Truck has a new OEM TPS, LCE Big bore throttle body, fuel tank and pump.  Vacuum hoses are also new.  I have checked the cold start timer with a DMM and it is reading in spec with FSM.  Also verified TPS readings with DMM.   Pulled vacuum line off booster and suction released. Check valve on booster line seems to be working properly as well. 

Any help would be greatly appreciated. 

[gnob]

Sounds like idle is too high. Fuel issue is probably the fuel pump relay or possibly efi relay

[liveoak]

Sounds like idle is too high. Fuel issue is probably the fuel pump relay or possibly efi relay

idle too high x2. surging with foot on the brake is a sign of either high idle or vacuum leak. hot soak hard start could be numerous things

[Carolina82 [OP]]

I will have to figure out a way to check the rpms, I don't have a tach.   I will check the relays.   

[blackdiamond]

My 4Runner with 22RE was starting ok, but idling like it had a big cam in it.  Two of the valves were way out.  Make sure your valves are adjust correctly.  It had clearly gotten slowly worse over the past few years at a rate slow enough that I didn't recognize the issue until it reached critical mass and starting idling very poorly.

[toyoboy]

if you can't adjust the idle low enough you may need to adjust the idle stop, it is a screw under the bell crank with a jam nut on it, loosen the jam nut and loosen the screw until the throttle plate closes completely (you will have to remove the section of ducting just before it to see if it is closed) then turn it back in one quarter turn so that it doesn't sit against the aluminum housing, tighten the jam nut, and readjust your idle.

i have seen people adjust the stop rather then the idle screw in order to adjust the idle, this will throw off the tps and possibly let to much air past for the idle screw to correct.

[Carolina82 [OP]]

Adjusted the idle down to the point where I have to rev it up to excite the alternator.   Don't think that is the issue. 

I will keep piddling with it, will adjust the valves within the next few days.   

[Carolina82 [OP]]

Still chipping away at it.  So I finally got around to adjusting the valves.  Intake valves were to loose and exhaust valves were too tight. Only by about .003 per side though.   Did not help the issue but did make the engine run quieter.

Adjusted the throttle body per FSM specs and it dosen't seem to surge when braking now, but seems to have another issue I now notice.   When I let off the throttle easy it will idle high, if I tap the throttle it will drop to normal RPM, same happens when I do it manually under the hood. I do not see any mechanical binding and the throttle body is clean.  It also has a intermittent miss at idle and when at a constant rev in neutral.  I do not notice anything abnormal when driving.  I checked the timing and it seems to jump around slightly when idling, not sure if that is normal.  Also the temp gauge stays only about 1/4 of the way up at operating temp instead of 1/2 way (faulty ecu temp sensor??)   I double checked the TPS after the throttle body adjustment.     

Could be better described as the engine seems to shake more than I would assume to be normal.   

[gnob]

Um if the truck is not temping up properly, you need to be looking at t-stat.  Gauge and ecu use two different senders.

[Carolina82 [OP]]

Um if the truck is not temping up properly, you need to be looking at t-stat.  Gauge and ecu use two different senders.

Radiator, cap, water pump, hoses and t-stat are all new OEM. 

[Slabzilla]

Some simple things often overlooked, High idle-lube throttle cable, they get sticky with age. A random miss is often a leaking sparkplug wire or an arcing Dizzy cap. Just my two point five cents, take it for what you can use.   

[toyoboy]

http://www.lcengineering.com/LCTechPages/pdf/Throttle%20Position%20Sensor%20Adjustment.pdf

[toyoboy]

you have to readjust the timing after adjusting basically anything else

[Carolina82 [OP]]

Verified timing, its dead nuts per FSM.  Guess I'll have to live with it until it gets worse. 

[Carolina82 [OP]]

Update:    So I've been driving it a lot more and i'm still having the hard start issue, but i've narrowed it down. If the engine is cold it starts fine.  If I drive it to operating temp, and start it back up at operating temp it starts fine.   The issue occurs when I drive it to operating temp and let it sit until it cools off a bit but not to ambient air temp (temp hand is roughly half way between cold and operating temp).


*called 22re performance and he is saying check the fuel pressure regulator*  Will keep updated.

[Carolina82 [OP]]

Installed a LCE fuel pressure gauge, roughly 35psi at idle.  As soon as I switched the engine off the fuel pressure dropped to 0psi.   Installed a new fuel pressure regulator (OEM Part # 23280-35030) and now it holds at 35psi with the engine off.  Truck is fixed, no more hard start issues!           The truck does run a little smoother with the fuel pressure regulator vacuum hose disconnected and blocked off though.    Gonna peep at the hose routing tomorrow and make sure everything is routed properly.

Hopefully this could help someone in the future.