Injector(s) vs. Wiring vs. ECU vs. ??

[timsrv]

I could be wrong here, but I don't think there is any difference between CA vans and those sold in the other 49 states. As for getting your van on the road, something is certainly missing here, but At this point I have absolutely no clue what it is. FYI, without hands on, the only things anybody can offer you is going to be speculation and guesses . Sorry this hasn't been enough for you. I'm sure you will find the the problem soon, and when you do, please report back with your findings and the solution. Tim

[llamavan]

I know the ECUs for California vans are different starting in 1986. Word of mouth is that the differences are strictly to do with the emissions system, but I've not had occasion to stumble on the specifics yet (only have one CA van that I work on ... so far).

Looking back to your very first post, you mention "an odd elec. type smell the morning it started misfiring" ... so testing the ECU (just to rule that out) and then inspecting and testing the wiring, particularly between ECU and the injectors (starting with anything that looks weird, and especially anything that sits next to hot engine parts) might be a good next step. Or vice-versa, since the code 51 is pre-existing and, as Tim mentioned earlier, it's really rare for an ECU to go bad (much more common for people to blame them). I worry enough about accidentally mangling 20+ year-old wiring myself; I shudder to think what a non-van-familiar mechanic might do. Flaky (damaged) wiring to the injectors would have a similar effect as bad injectors. I've also known people to mistake a really toasted TPS for "needs injector work", and you are getting that code 51.

Before you remove the intake manifold, order in the appropriate gasket(s) for as far as you think you might be going in. Toyota P/N 17176-73011 (the gasket between the two halves of the intake manifold) would be a must-have; a gasket for the EGR valve (Toyota P/N 25627-31020) might be good to have on hand since you mentioned a hissing sound (not normal on my vans). Also some vacuum hose; if you don't use it now, you will eventually.

Gwen

[Harbilly]

I'm interested in that gas smell after stopping. Not only do injector connectors fail but the things start leaking too. I was able to slide under the van and confirm a leaky injector after stopping the engine before I ripped it all apart. All my cylinders were still running, though, despite the leak.
I think vans that sit have more issues than vans that run - I know I have one of each.

[freeb]

Thanks for the help so far. Anything anybody throws out there is really appreciated. I'm learning hands on a lot of the basics with my Van and then some. So on one hand I'm enjoying the diagnosis but of course on the other its frustrating as #$*%!

I ordered an ECU off ebay. I dunno, just need to rule that out. Wishful thinking I guess. I did the resistance test at the ECU wire connectors according to the manual and got negative ohm readings. I honestly don't know if that points toward a problem with the ECU or something else but I guess I'll find out.

If that doesn't correct the problem I'll be pulling off the upper intake to check the injectors. Thanks for gasket references llamavan. I haven't been able to locate any fuel leaks but it may be worth taking another look at that. One thing that has been on my mind is the possibility that the injector wires got fried when I came close to overheating.

I'll let you all know what I find.

[freeb]

Some Updates:

Plugged in the ECU I bought off Ebay. No change. Finally pulled the upper half of the intake plenum off. I'm not really positive what I want to do next.

The first thing I noticed right away was a reddish brown color that dripped from the gas line when I disconnected it from the injector rail. I'm assuming it was rust. Probably not good.

Next thing was that the short and thin rubber hose that attaches to a fitting on the bottom right (firewall side) of the injector rail was not connected. I see that one end attaches to a thin metal line which loops around to the other side of the engine block and a rubber hose feeds into something with a red wire connection near the oil filter. I don't know what this is. Does anybody know?? Hope I'm not being to vague.

The EGR Valve had a really old gasket. May have been the reason I heard a vacuum leak in that area. Haven't been able to disconnect it from its pipe yet. Sprayed with some PB Blaster

The intake runners for #1 and #2 cylinders is really carbon and gunked up.

3 of the nuts for the chamber were loose!!

Does anybody know how the fuel delivery system works as far as getting the fuel to the injectors? Is it possible that it's not actually the injectors which are clogged? Could the fuel not be even making it to the #3 and 4 injectors for some reason?

The injectors wiring look okay. Didn't look like I have any leakage at the injectors. There was a lot of gunk around there and it seems that it would have been at least partially dissolved if they're leaking.

Time to tend to some bloody knuckles......

[llamavan]

Without even seeing it, I'm 99.999999% positive it's a vacuum hose. You'd have to have no sense of smell or vision to miss a gas or coolant leak, and those are the only other things that run around inside rubber hoses. So that's probably the source of your hissing noise. It could also be the source of the burning smell if it ended up resting on something hot.

There's a vacuum diagram pasted on the floor pan, driver's side (lift the seat to find it), but it's more of a reminder for those who already know what things look like. If you post a photo of the other end and the dangling end, I might be able to figure out where it's supposed to go (but hopefully someone else with hands-on experience will jump in — I'd just be deducing from diagrams).

I'm going to let someone with hands-on knowledge answer the fuel delivery (direction) question (and I hope someone does, so I can learn, too).

Sounds like taking the top of the air chamber off was the right move since you're finding lots of stuff that needs to be addressed.

Gwen

[timsrv]

That short rubber hose is most likely the vacuum line for the FPR (Fuel Pressure Regulator). Not having it hooked up would do 2 things: 1. Create a vacuum leak. & 2. Increase your fuel pressure. Since you have the manifold off, now would be a very good time to replace your FPR. These fail and are a PITA to replace with the manifold on, so now is a very good time to replace (consider it preventive maintenance).

The vacuum leak part of having that line disconnected is not good, but wouldn't create a problem to the degree you are having (you might not even notice). The increased fuel pressure is actually good (would make your van more resistant to vapor lock or "hot soak" issues). The "gunk" in these two runners, along with the wet plugs you reported earlier suggests you may have a blow-by issue (bad piston rings) or perhaps a leaking cold start injector. At any rate, since you have it mostly apart, take all the injectors into a shop to have them ultrasonically cleaned and tested. If there is a problem with any of them they will be able to tell you. I'm not sure what this costs in your area, but last time I had it done it cost me about $50. You will also need to replace all the rubber o-rings and rubber insulators that are used to mount each and every injector. Note: make sure that all the old parts are removed from your injectors AND the manifold before re-assembly (one sure way to screw things up is to re-assemble with both an old and a new o-ring or insulator stuck in there).

To find a place that can clean and check your injectors, just call your local Toyota service center and ask them where they take their injectors to have this done. There's usually at least one or 2 places that do this in every major city, and any reputable shop will know who it is.

Also, before you put the manifold back together, make sure to get it clean. Carbon and "gunk" in this area create problems. Make sure the big vacuum ports are clear of debris and gunk as well. If you can't get it clean, an automotive machine shop should have a washing machine that would do a nice job. Just call one and ask how much $$$. Good luck. Tim

[trestlehed]

Some Updates:
The first thing I noticed right away was a reddish brown color that dripped from the gas line when I disconnected it from the injector rail. I'm assuming it was rust. Probably not good.

You might have a rusted out gas tank. Back in the early '90's I bought a 1977 Toyota Chinook pop-top camper. It ran rough/power loss/stalling. I had the carb rebuilt as well as replacing everything such as wires, plugs, distributor, cap & rotor, etc.

I finally took it to a reputable independent Toyota mechanic who immediately found that my gas tank was full of rust and gunk. When I bought my 86 van, that was one of the first things I had checked out.

Remember how old these vans are... Original gas tanks 25 years old or so.

[freeb]

thanks for the replies. I agree that I probably had numerous vacuum leaks. Numerous.
I am bringing the injectors to be cleaned at Napa tomorrow. I'll be getting new O-rings also.
I think my EGR valve is still good. Diaphragm still moves up and down.
I'm a little uncomfortable going too crazy cleaning the inside of the intake chamber. Seems like if a bristle from a wire brush were left inside, I'd have problems.

The gas line that the reddish brown gas came from was the line that leads to the cold start injector. Wonder if rusty gas is left in this line still. Starts up easily when cold so the cold start injector should be good??

Hey trestlehead, I'm not sure what to do about this issue with the possibility of a rusty tank. I read that gas can also become gel like over time. I don't know why I didn't take the time to drain the tank. The old gas would be thru it by now but I'm not sure what to do about the tank itself now.

Just found out that the pictures I took of all my hoses prior to disassembly were lost from camera's memory. Fun.

[Sean]

I can't reccomend enough just taking in parts to a machine shop with a washer.... In doing my project I spent countless hours cleaning when I could have been more productive by taking them into the machine shop. The guy charged me about 20 bucks for a load of stuff and it got everything neat and clean. Well worth it to me.

you should definitely look into it and at least find out if it's worth it for you.

Sean

[skyflyer9]

I'd have to agree on taking the manifold to a shop to be run through the cleaner...

I must have spent four hours with brushes, rags, carb-cleaner, etc. trying to get my intake manifold clean. It was a complete mess, and you can't really get into the inner chambers all that well.

I finally took it in to a local shop, picked it up the next morning, and it was like night and day - what a difference!

Granted, my intake manifold was VERY dirty (340K miles on it at that point), but I should have just taken it to the shop in the first place...

[freeb]

I hadn't actually removed the fuel rail and injectors yet. Did that today. Caked in rust in the end of the 2 dead cylinder's injectors. A fine powder of rust came pouring out of the rail like an hour glass.

Had the 4 injectors cleaned and some o-rings etc. replaced for $135 at Napa. One injector tested 10 cc. over spec. They said it would still work but I wanted to see if anybody had any thoughts on that.

I'm gonna look into the intake manifold cleaning. How does it get so gummed up???

[timsrv]

Considering the PITA it is to remove these, I wouldn't install one that tests out of spec. If you're on a budget, get one at a salvage yard and have that one cleaned and tested. Re-assemble only after you have 4 confirmed good ones.

If the gunk inside your manifold has a trail that leads to the PCV and valve cover vent ports, then it's due to crank-case ventilation and can be normal. Intake manifolds eventually get fouled up inside due to the PCV (Positive Crankcase Ventilation) and the valve cover vent hose. These 2 larger intake ports suck the oily vapor out of the top your valve cover and recycle it back into the combustion areas. This is good because it helps prevent the formation of sludge and condensation inside the engine. It also keeps the interior of the engine at a slight negative pressure which helps inhibit external oil leaks (reduces the outward pressures on the gaskets and seals). The down side to oily vapor moving through your intake manifold is a gradual build up of oily residue inside. This build-up is very gradual but steady. Another negative aspect to crank case ventilation is over time this build-up problem becomes accelerated (due to normal engine wear). As the piston rings wear they slowly allow more and more combustion pressure/gasses to escape down and around the piston and into the crank case. The combined combustion leaks from multiple cylinders can eventually match or overcome the CFM (Cubic Feet per Minute) of vapor these vent ports can move.........and that creates a positive pressure inside the engine.

Now instead of these vent ports sucking in small amounts of vapor, they become overwhelmed by positive pressure force feeding combustion gasses into them (for a 2nd trip through the engine along with the additional vaporized oil that was picked up along the way).

One of the things you can do to check for blow-by is remove the PCV valve from the valve cover while the engine is running (leave the valve hooked up to the vacuum hose). If you can see and feel vapor puffing out of the valve cover, then you have a blow-by issue. This can be a good indication that it's time for a rebuild or at least a new set of rings.

If the residue trail inside the manifold goes back to the cold start injector, then it's possible this injector has been leaking and the build up is a result of that. Tim

[freeb]

Thanks for that info Tim. My manifold is a bit worse in the first two runners but all four are actually pretty black and gummed up. I will try the PCV valve test once reassembled. I think I remember doing that and getting getting the air coming out. The fuel line to my cold start injector had rusty gas in it so I suppose I should check the injector also.

I can't seem to get the bolt that holds the banjo fitting for the fuel line on the bottom of the fuel filter loose. I can't get a wrench around the part on the filter that would allow you to hold it in place while turning the bolt. Am I missing something or am I just not using the right tool?

[timsrv]

Yeah, that one is always a PITA. At least that bottom line is flexible, so it can moved to a better spot. Take the top line off 1st, then take the mount bracket off the block. Now you can maneuver it around to a better spot and use a back-up wrench. Just be sure to use a socket or a box end on the banjo bolt so you don't bugger it up. Don't ask me why they made that job so unnecessarily difficult. Tim

[freeb]

Glad it wasn't just me in thinking that bottom line on the filter was a PITA. Now that I got the it removed I'm trying to figure out what the best approach to the rust in my tank would be. I did drain it and it was rusty and had some sediment. I think that the injectors clogged when it ran down close to empty on the fuel gauge.

[NEC]

I used to clean my old VW tanks with some water, a heavy chain and some Tide with bleach. I would remove and drain the tank, throw in a section of heavy chain, some water and some laundry soap. Shake it all around for a while, drain, rinse, repeat. This worked well for my old rusty steel tanks on the vws.

[freeb]

Thanks for that idea NEC. I've come across stuff on the internet recommending muriadic acid. I'd like not to have to dump a bunch of acid into the ground though.
Just dropped the gas tank and I have a couple of pictures.
The first is inside the tank. There is a partition built in where the fuel pump goes. Entire tank is rusted but no leaks.



This picture is the fuel pump attached to its very rusted bracket. The fuel sender gauge is also in the picture. I think that's what it is anyway.


I'm not really sure where I should be starting now. I probably can't afford a new tank at this point. Fuel pump and gauge were working. Is it possible to just clean them? I'm thinking that anything at a salvage yard is going to be in the same condition. Appreciate any ideas.
ben

[timsrv]

I've had several van tanks apart and yours is the worst I've seen. I would suspect a salvage yard tank would look nicer than that inside, but who knows. If you can find one in a salvage yard (keep in mind 2wds and 4wds have different tanks), you could always look inside before purchasing.

Since everything was working, you could always clean per NEC's directions and put it back in. FWIW, your tank is rusty because that van sat around with an empty tank. Tanks that get filled regularly don't get rusty like that. Tim

PS: I have a good one I'd sell you for $40 complete with fuel pump. I already have the tank removed and sitting inside the van (I pulled it out of an 89 LE 4wd just like yours). Tim

[freeb]

My van's running strong again! Thanks Tim for the tank, pump and sender. Gauge is working fine. That was a cool trick. Had a couple incidents with fuel lines not being tightened enough and a coolant hose leaking at first start up. The coolant leak had me thinking I had a blown head gasket at first. Just sorta figured that would be next. Only needed to adjust a hose clamp position and leaking issue solved. Only issue I have now is the gas odor seeping into my house every time I open the door to my garage.

Next up is the obnoxious whine from the power steering pump. Hoping that cleaning the screen in the reservoir will fix it. Its leaking as well and the power steering is pretty intermittent.
ben