Exhaust repair dilemmas

[bigeo]

After posting frequently for awhile on that other TV website as a new van owner with lots of questions, I have a spent the last few years with few repairs and the experience to handle those that cropped up. Now, I am facing a bigger "project" again and not sure how to handle it. The background: I took my 87 (4wd, LE auto with almost 150k) in for a new muffler last spring and was told by the shop that the pipe between the muffler and the cat was rusted out and the cat was partially plugged. They quoted me on replacing both, but, since the van is exempt from further emissions testing where I live, I decided to lose the cat (wish it was that easy with the furry ones we got). The guy at the shop assured me that there would be no detrimental effects and it might enhance performance a bit. The van ran fine after the work was done and I felt that it was a good call.
When summer finally arrived in W. Washington and I was driving with the front windows down, there was a strong exhaust smell that I hadn't experienced before. Crawling underneath, I couldn't feel or hear a leak. I asked at the shop that did the work and the guy said that back pressure due to the plugged cat had likely caused a leak in the exhaust manifold gasket. Based on that, and the fact that there is at least one missing stud on the manifold, I decided that was the likely source of the exhaust smell in the cabin. I drove all summer with the windows up, intending to do the repair when I had time and could spare the van for a week. In the mean time, I have been doing some research which has caused my repair strategy to evolve.
Originally, I was just going to pull the manifold and just replace the gasket unless the manifold was cracked. After reading threads on the process of doing the work and realizing what was involved and also finding that a new ex. man. wasn't that expensive, I ordered one from 1st Toyota. Although at least one owner has managed to replace the exhaust manifold w/o removing the head, it seemed that my fat hands might not be up to the task and I started contemplating the possibility that I would be doing a head gasket as well. I did a HG on my 86 years ago, so I know what's involved and that got me thinking about things that should be done at the same time. Consequently, I ordered the "valve grind gasket kit" and new fuel pressure regulator (replacing the one on my 86 helped with "hot soak") and, When I found them for $35 each on Rock Auto, rebuilt injectors.
Since I am within a week or two of actually starting the work, I have been doing more research and it has made me wonder about a couple of things. First, how likely is it that I would be able to replace the exhaust manifold w/o pulling the head, and is it even worth it to try considering that would mean having to remove at least one broken stud and probably more "in the field"? Second, should I use the rebuilt injectors I bought? I forgot that when I did the HG on my 86 that I had the injectors cleaned and tested and reinstalled them and that worked out fine. I saw in a thread here that Tim recommends that route and expresses some skepticism about rebuilt injectors. I'm also wondering about a good source for the injector connectors. I should mention that the van runs great as it is although the exhaust leak has become quite audible.
It's good to be posting again. I had forgotten how cathartic it is to share one's worries with the tribe.

[timsrv]

Hey Einar! Welcome to TVT! I'm glad you found us .

I normally don't recommend doing head gaskets unless they are bad, but I can understand the desire to "do it once, do it right". Since you're in that far, and since blowing head gaskets ARE the Achilles heel of the van, it's probably not a bad idea. There are several threads here on TVT where all of your above questions have been addressed in great detail. Here's a good one with lots of links to related information: http://www.toyotavantech.com/forum/s...ng-Head-Gasket . Please take some pics and keep us up to date . I look forward to monitoring your progress & would be happy to help with any questions you might have. Tim

[bigeo]

Thanks for your response Tim and for this great site. The thread you linked is actually what got me thinking about some of these issues. So , if it was your van, would you use the rebuilt injectors from Rock Auto, or return them and send the originals to The Dr. ? I did a search here for exhaust manifold and didn't come up with anything that addressed the issue of replacing one w/o pulling the head. There is a thread on the other site with a write-up by a guy who has done it in which he mentions the need for small, double jointed hands, which I definitely don't have. So, I'm wondering, how tough is it to pull the exhaust manifold with the head still attached and drill out the broken studs on the vehicle? Even though I have purchased the parts to do it, I'm not committed to the idea of doing a HG on a vehicle that is running fine if the repair I need to do doesn't require it. Also, you mentioned in the thread about injectors that the Bosch style connectors that should fit my 87 are available, but you didn't mention a source. I'm sure I could track them down, but where do you get yours?

[timsrv]

I'm not qualified to know anything about the rebuilt rockauto injectors as I've never used them.........they are probably fine. Based on experience I am confident in old OEM injectors (after cleaning/testing) so I've never felt the need to spend money on anything else. Once I had a factory injector that would intermittently fire after long periods of inactivity, so I went to the salvage yard and got one to replace it. The injectors I'm currently running in my freshly rebuilt engine have over 250k miles on them and have only been cleaned & tested. Same thing for injector connectors. I know there are places that make these things new, but I am skeptical of the quality plastic they use. They are probably fine but I worry about how long they will hold up. To date I have only used connectors from the salvage yard. Whether Subaru, Toyota, or whatever I figure OEM quality is top notch. Of course I avoid taking used injector connectors from Toyota vans due to the extreme environment they have lived in. I take them with about 3 or more inches of wire then solder/shrink tube them into the van harness. On my rebuilt engine I built a removable injector harness so I could install/remove the engine without splitting the manifold........and yes, all the injector connectors are from Subarus in the salvage yard. Note: Since my van is an 89, it uses the Inverted Denso connectors (used in 88-89). All other years of van used the Bosch style. Here's a few pictures of my custom harness:







As for your broken stud question, there is a thread for that that's linked to the head gasket thread (linked to in my previous post). It's a bit time consuming but it works. I'm sure there are other ways, but that's the way I do it. BTW, unless you have a custom injector harness (like above), you need to remove the top half of the intake manifold to disconnect the engine wire harness from the injectors (this needs to be done before the head can be pulled). Once you've gotten that far removing the other manifolds isn't that big of deal. The worst part of pulling manifolds is dealing with the small fasteners and tubing on the back side of the manifold. If you cut an access hole for the "hose of death" then that makes it easier. FWIW, I've removed manifolds in the salvage yard before with only my basic "carry-in" tool kit. That job is always a little aggrevating, but I've never run into anything that was unsurmountable. Tim

[bigeo]

Thanks Tim for your thorough reply and for the great pics. That oil and dirt free engine compartment is an inspiration. I guess I will see how I feel when I get into it before deciding how far to go. I have decided to reuse my injectors (after treatment by The Dr.) Hoping I don't need new connectors, but just in case I want to be sure I understand what I would be looking for. You wrote in the thread referenced above that the "inverted Nippon" style connectors used on the 88/89 vans could be found on subarus. Were the Bosch style connectors used on Subarus as well and do you know off hand which years/models? I'll keep you posted once I get "under the hood."
Oh, and thanks to Endadamak for your reply. Unfortunately, I don't read Polish. If anyone is brave enough to follow that link, please let me know what it's about.

[timsrv]

To my knowledge the inverted Nippon style were only used on the 88-89 vans and a few Subarus (late 80's to early 90's), but still not too hard to find. Bosch (the kind you need) are very common and can be found on a large variety of vehicles. If you go to a pick & pull, I'm guessing you'll find them on at least 2 or 3 vehicles per row. Just look for them on rigs with easy access & good ventilation. Make sure they are in good shape. Also check the wires for stress and verify the conductors inside are clean and corrosion free. Tim

PS: Sorry about the spam. We need to update the forum again. Between me and Gwen we check the the site every few hrs but some still slip through the cracks. Just ignore them, we'll keep nuking them until we have time to address the update issue.

[gushaman]

wow, what a great thread. At work (i work at a toyota forklift dealership as a service tech) we take the heads off of 4yecs with exhaust manifold attached, and they also have the water pump mounted where our vans have the belt idler pulley. I cant remember if this is possible with the vans, but it sure makes all the head disassembly easier.

and great pics, I wish the van Im looking at now was as pretty as all that. but hey 150k 4wd five speed, i wont be able to complain much if/when i buy it.

[bigeo]

So, a mere 6 months later and I finally got around to doing this repair. The van has been "gutted" for about two weeks. The head has been cleaned up, valves ground, new guides and seals. The radiator has been recored. My injectors are on their way back from the good dr. in Gladstone. Still waiting on delivery of a few more parts from Rock Auto and 1st Toyota, but I'm hoping all will be in hand so I can get things back together this weekend. It turns out the rear arm of the exhaust manifold had a crack around 2/3s of its circumference and the leak had become quite audible. I am glad I pulled the head instead of just replacing the manifold. There was evidence of leakage between the two rear cylinders and it provided the opportunity to do a lot more "preventative maintenance". One of the things I did was replace the old injector connectors with salvaged ones from pull-a-part. The wires on the salvaged connectors were, of course, not the same color as those in the van, but I convinced myself that it didn't matter which way they were hooked up. After I did the first one, I started to have doubts about that conclusion, so I hooked up the rest of them with the common color wire to the van connectors (brown) to the common color wire from the "new" connectors (red/black). I asked Wayne (aka Dr. Injector) if there was a +/- to the terminals on the injectors and he said on most there isn't but some do have a "polarity". Since that first replacement connector that I soldered, shrink wrapped and nicely taped up was not done with a particular orientation in mind, I'm wondering if anyone can tell me if that is an issue on toy. vans.
I will post a full report when I get it put back together on what all I did and the results.

[timsrv]

Good question on polarity. Does it matter? I would think not, but considering what a PITA it is to access this area I have never taken the chance. I can tell you when I test injectors I never worry about polarity & they fire fine regardless.

One thing worth noting, I have never removed an exhaust manifold from a van with over 150k miles on it that didn't have a crack like you describe or didn't have that rear stud broken off. Toyota makes hardened exhaust manifold studs that are supposed to be better than the ones they used on our vans (they are black instead of shiny silver color). This last time around when I rebuilt my engine I used these studs (Toyota part #90116-10150) as they are supposed to hold up better. Of course it will only take about 20 years and/or ~200k miles before I know for sure . At any rate, I figured they couldn't be any worse. I've often wondered if the manifold only cracks AFTER it loses that stud, or if it will break regardless. If I'm still alive in 20 years and if that stud holds up......... I guess I'll know then . Tim

[bigeo]

Tim thanks for your input on the polarity question. As far as manifold studs go, I ordered enough to replace all of them, just in case, months ago from Rock Auto. The rear one was the only one broken off when I removed the head. I tried to find replacements like you describe (hardened steel) at local auto parts places and specialty hardware stores, because I don't really trust the shiny ones from Rock and they are a little short, but I struck out. I couldn't get the studs out of the flange on the old ex. man. in useable condition so I used the ones from Rock Auto to replace those as well. When I mounted the new manifold, the front stud broke. So now I have those shiny studs in several locations. I sure hope they last.

[bigeo]

It's a done deal! Got my van back together and it runs GREAT. Here is what I replaced or had worked over: new-exhaust manifold, water pump, FPR, fuel filter, air filter, all belts, several hoses, dist. cap, rotor, plug wires, plugs, bvsv. I had the head worked over with a valve grind, new guides and stem seals, the radiator recored, had my injectors cleaned and tested by "The Dr." in Portland and replaced the connectors with ones salvaged from pull-a-part (soldered and shrink wrapped). I would say that this job was less frustrating, but more time consuming than when I did the HG on my 86 about 6 years ago. A recently acquired air-impact tool really helped in a couple of instances. Maybe the message is that patience saves grief. The van started right up (after getting the new plug wires sorted out) and other than a few minor fluid leaks due to clamps not being tight enough there were no issues. I put well over $1k into the project, but hope to recoup the expense in many miles of fahrvergnugen.
interesting side note: The exhaust smell in the cabin while driving with the front windows open, which prompted me to start this process 6 months ago, is still there. I am going to try a tailpipe ext. with a 90 deg. bend next. Anyone have other ideas about possible causes/remedies?

[timsrv]

Congrats! Always nice to hear these type of success stories. The type of exhaust work you have left shouldn't be that expensive. Even if you end up needing a complete system it probably won't break the bank. Just take it in and have them check it for leaks and make a recommendation for repair. Personally I like the privately owned exhaust businesses where the owner works in the shop. Most of those guys are awesome & can work miracles for very reasonable prices.

I don't know if they are still there or if they are still "awesome", but when I lived in your area I would take my custom built rigs into "Airport Welding" in Snohomish (right next to Harvey Field). I had to drive over 1/2 hr to get there but it was always worth it. Tim

[bigeo]

Thanks tim. From your reply I gather that you still suspect that I have a leak in the ex. system. This issue with exhaust in the cabin first appeared after I had the muffler replaced and the cat. removed (see my first post in this thread). As far as I can tell, the shop did a good job and I can't detect any spot where the system is leaking. Can you think of any reason why eliminating the cat would cause this problem? The idea for adding an elbow on the end of the tailpipe came from a post on tvp where someone claimed that this solved their issue with exhaust getting in. I could see that working on the theory that when you open the front windows you create a pressure differential in the cabin that somehow pulls exhaust in around the rear hatch and, if you divert the ex. gas, it isn't there to be pulled in. Just a theory, but a pretty easy/cheap experiment to test it.

[timsrv]

If you just had work done then I'm guessing it's not a leak. Could very well be the random location of the tail pipe termination creating the problem. Yes, next thing to do is extend/or bend the tail pipe to a different location. Here's a picture of the last one I had done.



I had this done on a customer's van right after I replaced the engine (and a ton of other stuff). I only drove the van a few miles, but he's been driving it for over a year now & I haven't heard any complaints. Tim

[bigeo]

That's what I'm talking about! I'll give it a try. thanks

[bareskier]

thanks for the responses here. another head has been purchased for a good price and shopped. injectors are also in the shop for cleaning, etc. all known parts have been ordered and are showing up daily. thanks to all who are responsible for inventing the internet thus making the ordering of all these out dated parts a possible task.
i ordered the parts and got them quickly for the injector harness mod shown here somewhere in a past post. what i need now is any pictures or info on choosing the best location where to cut the engine harness for the 4 wire conn.s and how the harness was sealed after the solder/shrink tube task of the delphi plugs was completed.
is the blue tape shown in the pictures something special for heat or regular e tape or something else entirely? how are the ends sealed to/around the plugs and connectors? any pixs or words will be greatly appreciated. so far im on track for a weekend reassembly, i've just got to get all these damned bolts and hoses sorted out first.
getting parts was a time consuming task, even with the numbers in hand.
thanks again for the continued help thru your responses. - mike

[timsrv]

thanks to all who are responsible for inventing the internet thus making the ordering of all these out dated parts a possible task.

Yes, thank you Al Gore for making all this possible

what i need now is any pictures or info on choosing the best location where to cut the engine harness for the 4 wire conn.s and how the harness was sealed after the solder/shrink tube task of the delphi plugs was completed. is the blue tape shown in the pictures something special for heat or regular e tape or something else entirely? how are the ends sealed to/around the plugs and connectors? any pixs or words will be greatly appreciated.

I think the Delphi plugs are good, but they are a bit finicky and time consuming to put together. You also need some good specialty crimpers for these and they are a bit spendy. Due to the time consuming part, the last time I did this I switched over to Weatherpack. Weatherpack connectors are not as compact as the Delphi, but they are still high quality and easier to work with. I couldn't find an 8 position plug made by Weatherpack, so I went with (2) 4 position plugs. You still need a specialty crimper for weatherpack, but it's cheap and works good. Another thing regarding the Weatherpack, the design encourages better pin alignment and grips onto the pins better (at least in my opinion). Here's a quote from a post regarding this mod.

Note 1: Links are embedded into the text below. If you want to know more specific info, just click on the related text.

Note 2: If you want to view the original thread, just click on the little arrow in the top left of the quoted section.

One thing that always annoyed me with the van is the requirement to remove the top half of the intake manifold just to connect/disconnect the engine wire harness to the fuel injectors. The last time I did this I cut the injector part of the harness off & built a removable injector harness (it worked great). This makes it possible to completely assemble the engine before installation. I liked it so much I built a removable harness for this one too (old connectors were shot anyhow). I'm using Standard part #S697 Bosch style injector connectors w/wire and 4 PIN SQ 16-14 AWG Weatherpack connectors. I use 16 AWG automotive primary stranded wire to go from the injector connectors to the Weatherpack connectors. I solder & shrink tube the connections to each injector connector wire, then cover the assembled harness with more shrink tubing. Note: Special crimpers are required for the Weatherpack connectors. If you work with these type connectors (also used on GM) I highly recommend having a Delphi Packard Weatherpack Terminal Release Tool in case you need to pull pins back out. Here is the finished harness:


Male connector positions A&B power injector #1 & positions C&D power injector #2. Female connector positions D&C power injector #3 & positions B&A power injector #4.

If you already purchased the Delphi plug, don't worry, its a great plug. You'll likely need a few extra pins to practice with though as these are easy to mess up when you're learning. If you haven't already got the crimper, then you may want to switch to the Weatherpack as you could buy the Weatherpack connectors and their crimper for less $$$ than the Delphi crimper alone. Both the Delphi and the Weatherpack connectors come with everything you need to seal the wires to the connector. It's all done with soft rubber. The Weatherpack has individual little rubber seals (one for each side of each wire, whereas the Delphi does it with one bigger seal (per side) with multiple holes. As for sealing on the injector side, I didn't worry about it. Mine are sealed as good as the original Toyota ones. On the last harness I built (the Weatherpack one) I was able to stretch the shrink tubing over the edge of the injector connectors and seal them to the harness by shrinking it down. Good luck and have fun with it. I enjoyed taking a break from the garage to do the harness. I commandeered the kitchen table . It was nice to sit down and work in a clean environment for a change. I had all my connector pieces, wire, shrink tubing, strippers, crimpers, and a heat gun all laid out in front of me. Tim