budgetbuilder

keep us posted if you find the problem. I have something very similiar going on with my 87 4runner also. Been chasing the problem for the last 4 months +

Replaced tons of parts already bout to throw in the towel and have it towed in.

What is your fuel pressure at idle?
does your truck idle fine at 750rpm?

Nickka

Did anyone figure this out? It is happening to me now...

87 OR Coast Runner

Yeah, ditto here. I am at about wits end now. Haven't done a compression check yet....... because I'm afraid that it WILL be the valves.

Was there any solutions to Y'all's problems???

thefishguy77

iTrader: (1)

The compression check will tell you more with less work than just about anything else. Its really easy and cost very little 20-40 bucks at most. Besides it may let you know that you don't have to touch the head gasket.
Good luck.

Edit. Have the last 2 posters before me checked to see if you are throwing codes. Many symptoms can overlap different problems.

87 OR Coast Runner

Yuppers, I did. This runner ALWAYS throws a code 11 (FSM doesn't even tell you what THAT is). No other codes throughout this (rapidly) progressive decline in performance, until recently. I can't remember what system or unit I checked, but after I did, it threw a code 28. Code 28 isn't even listed in the FSM. Keep in mind, the FSM is for a 1988 RE. Mine is a 1897 RE and probably a CALI vehicle as well (fuel filter is different). I'm told there is no such think as a 1987 FSM.

Thanks for responding and helping.

Finally4running

Sounds like the effects of ethanol fuel to me. I can tell an obvious difference in performance between the two in my 88 22re and have seen several ruined fuel pumps, sludged tanks, etc. in various makes of vehicles. The owners manual flat says No ethanol fuel

thefishguy77

iTrader: (1)

Funny that thought crossed my mind as well

harleycharkey

Try pinching off your return hose from the fuel regulator while it is running. This will pressurize the fuel system. Smell and look for leaks. If it pressurizes you know you are getting fuel to the injectors. If you find leaks, take care of them. Depending on the location of the leak it could contribute to a miss or stumble. Possibly at the top of an injector creating a different type of vacuum leak or air bubble in the fuel injector itself. Put in all new injector seals lubing each one and take your time doing it. Next when you re-install your plenum to intake use a sealer on both surfaces and a gasket. I use Indian Head shellac. There my be other ways to go but it works on heads too. Mine I am happy to say is running great. 20+mpg on my first full tank since. I only spent $21 on injector seals on this fix (I had the sealer from past builds) Cheapest fix I can remember I a great while. You probably know the cost of the infinite parts you can replace. I Have rebuilt this engine , new head from previous owner who used stop leak to cover the head gasket problem that turned out to be 3 cracks in head between valve seats. Anyway I love my truck and especially since this find. Good luck to you and I hope this may help. Charley from Newport,NC

87 OR Coast Runner

Thanks, Finally. I don't know if our fuel has ethanol or not. I thought all fuels DID these days. But, my tank and pump are squeaky clean and I replaced the fuel filter just to be sure.

I did a compression check. Respectively, 1 - 4 are at: 171, 167, 175 & 156. That number 4 is a bit low. Threw some oil in there and it didn't change. Since that means it's not valves I don't think the difference is contributing to the performance issue.

My next step is to replace the spark plugs, even though all 4 look great. Cheap insurance before I go diving into the injectors and plenum. Anyone know much about the fuel rail??? The FSM says nothing (that I found) about anything between the pressure regulator and the injectors.

Thanks All !

harleycharkey

My note was to give you a trick that would tell you you have a working fuel system for an easy check. Pinch the return hose to discover 1. Does it run better with more fuel pressure? 2. Is there any leaks in the fuel system? especially before the injectors. This would mean an air leak that would definitely relate to fuel system problems and missing and lack of response. This is simple and cheap. It cost nothing to prove you have no leaks in your fuel system. If you do then possibly $21.00 for 4 sets of injector seals. Of course you should start with a matched set of injectors but chances are they are working but to what degree. ? I purchase a set from LCE and no worries. Not a bad price for a balanced set and you can retain your old ones for other build/repair projects.
As for the sealing of the plenum to intake that will be in case you do injector seals. Start with the return hose pinch. That may lead you to your answer or it may not. This is not in a manual. This is something I discovered after many other things I tried from the manual and ran out of things to try. Good luck.

harleycharkey

A thought on the plugs. Those sucker are probably ok. Pull each plug wire while it is running, notice a change or not in RPM. No change means bad plug , wire or something in that cylinder. go from that point to a fix.
As to the add oil to each cylinder and check the compression. This would indicate bad or good rings. It would not affect a poor valve seal. The oil will end up around the piston in the ring seats. It will help for a few strokes in gaining compression. You should check the valves in that cylinder for possibly being too tight. Could be that or warped or burnt.
I hope any of this can short cut you to a cheap fix, Good Luck. Charley

87 OR Coast Runner

Thanks Charley. Yeah, I was referring to fact that the oil in the cylinder indicating rings, not valves. That's why I wasn't too concerned as I am chasing a rapid performance change, not a slow age thing.

I will do the pinch again. I did it before and found no leaks and the RPM did not change.

Since I don't want to throw money at it, I want to do some no-cost things first. I'm thinking about removing and testing the AFS and the TPS. The only problem..... the throttle position sensor has two screws, top and bottom. That bottom one is impossible to get too. Any thoughts on hwo to do it?

Thanks,
Robert

87 OR Coast Runner

Charley. I forgot to mention.......

I replaced the plugs anyway, yesterday (cheap insurance)...... no change.

I replaced the plug wires and rotor and cap a few days ago (again, nothing wrong with them, but cheap insurance)..... no change.

I also did the propane torch trick, with my free hand covering my ear for the eminent explosion (Gawd that made me nervous)........ no rise in RPM. All though I can't say (with the fear factor) that I did it very thoroughly.

harleycharkey

Robert, I am not aware of the propane torch thing. You can fill me in on that one. As far as the TPS. Been down that road. LC Engineering has a little thing on that. Get Metric theaded allen head bolts. The allen head is 3mm. Not sure of thread dia. Lenght I got I believe was 5/8" Best to do is cary your old hex heads to a hardware and match them with the same thread and lenght with a allen head. Pick up a Ball head allen wrench to fit. Makes it way easy to adjust. LC Engineering Has also the Adjustment Procedure there also. You will find it. They have a nice web site. While your there check out the different 22re engines that I will never have Damit! Sorry just venting. Over on I believe the Crawler website there is a guy frankenyota that has a staight to the point TPS setting that I used the last time or two that seems to say that you don't have to be exact with the settings the way LCE seems to put it. Anyway keep it up I believe it is a simple thing It is just a process and it can be enjoyable and frustrating at the same time. They are good little engines. Charley

harleycharkey

Robert, What area are in. West coast? We seem to be on different schedules. I am East coast NC. It is 6:07 PM now. April Fools Day. Charley

87 OR Coast Runner

Charley. I'm on the west coast. Central Oregon coast, about a 10th of a mile from the rocky shoreline. It's beautiful here. Check out Depoe Bay on Google (note the spelling of Depoe).

On the TPS, my concern is how to get that bottom, stock, Phillips head bolt out. It can't be reached by conventional means! Unless I drain the coolant and take out that water temp system thingy.

Robert

PS I keep strange hours anyway. Sometimes up at 2am, other times sleeping a lot during the day. Wife and my schedules conflict a lot.

Zatara

I had a very similar issue for a year on my 1992 Pickup 22RE. I checked and replaced everything, even cut the harness to see the injector wires which were perfect, but nothing worked. I then replaced the ECU and the problem was gone. If there's a local with the same truck then try swapping it in. I purchased mine on ebay for $125 shipped. Good luck

Fernando

nashulee

So I had this same issue. I chased and chased, and what I found to be the issue was the injector clips were faulty. The guy that had installed them last, broke the clips which is very common, he rigged them up to stay on with zip ties, but after about 30 minutes of driving, I guess they would get hot enough to wiggle loos and cause a huge miss.

One day when I was extremely frustrated , I was staring at the truck having tried everything I could find, and I noticed the back injector plug looked , weird, so I reached back in there and as I moved the wiring around to get to it the thing just fell off. It had barely been on, I got it back on and secured the zip ties, better and tighter and the problem never showed up again.

I ended up ordering more clips and putting them on.

Hope this helps