88 4runner 3VZE 6 Cyl - after running on interstate/highway at higher speed, if I stop for gas or food and turn off the engine for several minutes, when I strat it back up the engine idles rough and I have to give it some gas for 15 seconds or so to clear it up. What could be causing this? I have the plenum off now as I'm replacing the valve cover gaskets. Was wondering if it might be something located on the plenum. Also where are the cam seals and how would I know I had a leak?
Country: United StatesMake: ToyotaModel: 1988 Toyota 4RunnerYear: 1988Engine: 3VZE
Removed plenum, replacing PCV valve and valve cover gaskets, and plenum gasket.
When was your last tune up? how old is that fuel filter? has the egr & throttle body been serviced recently?
tune up by auto shop - been several years. I replaced plugs and wires myself last March.
EGR and throttle body haven't been serviced that I know of.
fuel filter - no telling
You have several issues that could be causing your problems, I'd first check the plugs & plan on new NGK or Denso plugs, a new distributor cap & rotor. I would remove & clean the EGR, verify that is works & re-install. Since the plenum is off, use a liberal amount of
O2 sensor safe TB/Air intake cleaner & clean your TB well. It often requires a semi-stiff brush to remove the carbon build up.
I'm not exactly sure what you mean by idles rough, but these things should take care of any misfires or loaded up cylinders.
Yes, it would be a good idea to change that fuel filter. Wear crappy clothes as you will take a gas bath doing so
I think your issue is old spark plugs more than anything, & quite possibly a distributor rotor that is over due for replacement, they'll run almost worn to a nub but not well. I also highly recommend NGK plug wires, they are well worth the extra $20.
Also, I would perform a compression test on that engine.
Your cam seals are behind your cam pulleys on the front of the cylinder heads. You can not see a leaking cam seal unless the majority of the timing components are removed & the rear timing cover removed. Leaking cam seals would result in loss of oil only & lack of oiling to the cams. That may present itself with oil dripping down the engine, however, since your oil filter is there on the left & power steering pump/reservoir is right there on the right, there could be much oil on the engine & not necessarily from leaking cam seals. Those are usually addressed with timing belt changes.
I think you are just in need for another major tune up. Here are a few guidelines that I use. Semi-synthetic oil every 3K, new rotor every oil change, new dist. cap/NGK/Denso plugs every other oil change, new wires every 2 plug changes, new air filter with plugs or as needed, new fuel filter every 50K, EGR & TB service with plug changes.
Additionally, just so you are aware, depressing the gas pedal does not introduce more fuel to the system, but opens up that butterfly that you see in the TB, that in turn brings in more air to intake, that is then assessed by the EFI system in which case it adjusts the ignition timing & regulates the correct amount of fuel going into the plenum, so just pressing the gas pedal does not necessarily bring in fuel but does bring in air & sets off many reactions in the system to compensate for that.
Had same problem before I put new NGK plugs and wires in last March. I'll try the rotor.
where is the fuel filter located, under the truck near the parking brake cable?
What's a TB service?
What maintenance do you do on the EGR? blast with compressed air?
do you have some black smoke after this happens, if so sounds like you have a leaking fuel injector orf several, remove injectors and inspect for nozzle stains, replace as nessasary
no black smoke. and it only happens after running at highway speed for extended time. not affected driving around town.
Although I appreciate Scionking's info, the overpost was unprofessional & un-needed. A leaking injector would foul a plug & not come around. Your issue sounds tune up based, & based on lack thereof I think needs several things addressed and in fact sounds like a stuck egr. Brian40494.6369363079
stuck EGR causing rough idle after highway travel? replace or clean?
Yes, that is possible, in my experience with the 3vze at least. I don't think that is the only issue either. Your tune up schedule is spotty & incomplete at best. Until all the items I mentioned above are known to be non-issues, you can't very well diagnose your hot start issues to any one of them. I'd be interested in what the plugs look like too. As long as the egr moves I see no need to replace it. If it does not move under vacuum pressure than yes it will need replaced. .
plugs are new NGK
What did the old ones look like? or what are these ones starting to look like?
old Denso plugs looked good, not too corroded considering they'd been in for over 5 years
You had plugs in there for 5 years?.. and I'm interested in the coloring of the electrodes after 5 years.. yeah you just need a complete tune up including; cap, rotor, air filter, fuel filter, clean egr, TB service, replace any dried out vac hoses, adjust the valves, and check the catalytic converter for clogs. If after a complete tune up your issues persist, we can then start to diagnose your issues.
ok. how do you clean the egr? what is TB?
TB = throttle body. The egr is easiest cleaned is a parts cleaner, but as long as it is removed spraying it liberally with intake cleaner works well. I often let them soak too.