Severe Engine/Compression Issue - Next Steps?

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@Rifleman I've driven it around the block, I didn't want to get out and drive if something isn't just right but i might go for it. I did check the compression on #1 and it's 180psi, so that should rule out a valve issue correct? I didn't remove my shims from my buckets and they all went back on the same valves they came off of.
 
Lack of fuel - Swap injector 1 and 2 to see if the problem follows the injector.
Vacuum leak - are there any vacuum ports on the #1 intake runner?
Bad spark plug - I've managed to internally damage new plugs, might be worth while to swap plugs between #1 and #2 to see if the issue follows the plug.
Valves seem good with that kind of compression.
 
I recall someone else here having the RPM "hunting" thing going on. It was either the temperature sensor (there are 2) or the knock sensors (there are 2). Not uncommon to miss or break one of the plugs on the knock sensors under the intake manifold.

Otherwise, congratulations for getting it running again! I understand how anti-climactic it is when it sputters and coughs and is not what you've been dreaming of for the last month of rebuilding!

Good Luck!
 
@JeepinPete I tried a different spark plug, still didn't make a difference.

By difference, I don't get any tangible result from unplugging the spark plug wire from the distributor while she's running like I do with the other five. I've gone through my back he minds a couple of times, and don't think I have anything disconnected; I replaced most of them so I wouldn't have dry rot issues.

Any idea whether this could be related to the fuel pressure regulator? She seems to idle up a bit when I disconnect the vacuum line. I'm searching now to try to find test steps for the fuel pressure regulator, it seems like that might be the issue since it sits right on top of injector number one??

@BILT4ME I replaced both of my knock sensors and their connectors because the wires were melted; in the past when I got the knock sensor issue it threw a code. I'll see if I can test the temperature sensors, but the smoking gun is definitely something with #1 missing since it's plug looked strange and it doesn't seem to be contributing anything.

It feels great to have it running again, just want to enjoy it now and not be troubleshooting gremlins!!
 
Have you ohm'd the #1 spark plug wire?
 
@GeoRoss I tried a spare older wire and plug.
 
sounds to me like a clogged injector.

first verify spark by plugging a spare plug into the #1 wire - lay the plug on the engine and start it up to observe the spark on the spare plug. I doubt it is the issue since you changed out the wire, but it the the easiest to check first.

I wouldn't expect it to be the pressure regulator or knock sensors etc as the other 5 cylinders are running fine.

Assuming there is nothing physically blocking the intake for #1 (no rag left in the intake tube when installing the manifold) then the only thing left is the injector...
 
@Mark WV the spark is getting to the plug, and tried 2 different plugs and wires.

I pulled off the fuel pressure regulator and ran some seafoam through it as well as soaked some into the injector while providing 12v to the injector pins rapidly(it clicks open appropriately).

My plan is to remove the throttle body and try to loosen the fuel rail with the manifold still in place, then swap injectors 1 and 2 and see if the issue moves. If so, I'll find some new injectors(may as well do all of them if I have to take the rail off yet again). Anything I might be missing???
 
dcbthr33 said:
@Mark WV the spark is getting to the plug, and tried 2 different plugs and wires.

I pulled off the fuel pressure regulator and ran some seafoam through it as well as soaked some into the injector while providing 12v to the injector pins rapidly(it clicks open appropriately).

My plan is to remove the throttle body and try to loosen the fuel rail with the manifold still in place, then swap injectors 1 and 2 and see if the issue moves. If so, I'll find some new injectors(may as well do all of them if I have to take the rail off yet again). Anything I might be missing???
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Reading back through this thread the injectors are the only thing you did not test/address. Since you know you have spark to cylinder #1 (now) then it only leaves two possibilities (assuming all the rest are working):

1. Injector
2. Low/No Compression in that cylinder.

Personally, I wouldn't bother 'swapping' the two injectors. Just get a new one and put it in that spot. You can ohm the old one (should be 12-14 ohms), but short of hooking it up and doing a spray test you really can't tell much. Just because its 'clicking' doesn't mean its working correctly. Make double darn sure you are getting voltage through that injector harness and connector. I use a small dab of dielectric grease on those connectors just to be sure.
 
you stated the injector was clicking while the engine was running, so the wiring to the injector can probably be ruled out.
I would guess the injector ingested a piece of old seal during disassembly / reassembly.
when you have it out to move it from 1 to 2, tap it upside down on a tabletop to see if anything dislodges.

And also I wasn't completely kidding about the rag in the intake - Wouldn't be the first time I have seen it happen....
 
I agree with Flintknapper - if it is that much trouble to get to the injector, just install a new one on #1 and don't bother switching.
 
Mark WV said:
you stated the injector was clicking while the engine was running, so the wiring to the injector can probably be ruled out.
I would guess the injector ingested a piece of old seal during disassembly / reassembly.
when you have it out to move it from 1 to 2, tap it upside down on a tabletop to see if anything dislodges.

And also I wasn't completely kidding about the rag in the intake - Wouldn't be the first time I have seen it happen....
Click to expand...

Yes, it DOES happen!

I had an uncle that bought a Combine (agricultural implement) fairly cheap from a guy. He said the darn thing never ran right and no one could figure it out. He took it into the shop to have the injectors changed (it was a diesel) and they pulled the intake plenum and found two full-sized beer cans stuffed in the intake with an expiration date about the time the Combine was made. Someone in the factory was drinking on the line and needed a place to hide the empties. It was that way for at least 10 years before it was discovered.
 
Back to basics, you need air, fuel, and spark, to make power in each cylinder. Since you've confirmed the health of that cylinder with a compression reading of 180 PSI we can rule out valve problems. You said that you checked not only one, but two spark plugs, and wires, so we can rule out spark as your problem. So that leaves fuel, i know you said something about the pressure regulator, but if it was a problem with the regulator it would effect all your injectors, not just one. So that leaves you with the injector for that cylinder, along with it's plug and wiring harness. Pull the injector and check the plug and wiring harness per the FSM, if that checks out then go ahead and look at the injector. When you pull the injectors, look for crud blocking the fuel inlet on the top of that injector, next blow out the fuel rail with compressed air. If all that stuff checks out go ahead and replace the injector, or take it to a shop and have it cleaned.
 
Alright, i just ordered 6 remanufactured injectors that have good reviews. I figured that with 250k on them, who knows how long they've got and i dont want to take this thing off ever again if i can help it. They should be here Monday; lets hope that fixes everything!
 
dcbthr33 said:
Alright, i just ordered 6 remanufactured injectors that have good reviews. I figured that with 250k on them, who knows how long they've got and i dont want to take this thing off ever again if i can help it. They should be here Monday; lets hope that fixes everything!
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^^^^^^ Good move.

Too much trouble to pull/loosen the fuel rail to 'swap' a part, only to have to pull/loosen it again to replace the part. Since all of your injectors are old...chances are excellent you will benefit (easier starting, better power, slightly better mpg) from having injectors that have a proper spray pattern. So....basically you are replacing parts that might have been needed anyway.

I would argue with those who claim an injector "is either good or not good", so would those companies who clean them.

So even if this doesn't solve your problem, we will at least know it isn't your injector(s) and we can look elsewhere. You also will have improved your engines operation when we do find the problem.

Be sure and ohm all the 'new' injectors BEFORE you install them. Compare them to the ones you pulled off.
 
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@flintknapper everything you said is exactly what I was thinking. I'll be sure to meter the new ones! Thanks all for your help, I'll update on Monday.
 
Alright, fuel injectors came, and she is running WAY better. I metered the old ones and the new ones and they were all 14 ohms, so I'm guessing that #1 was leaking and making a too rich to fire condition. The miss is now gone and the idle is perfect. Only one problem remains – the pulsing idle issue. It will, on a half second interval, jump between 600 RPM down to 200 RPM and stall. It does not do it all the time; when it's not doing it, it idles perfectly. It seems to do it worse from a cold start, and in gear. If I unplug the TPS, it does not seem to do it either but then it idles close to 1000rpm and wont downshift. I adjusted the TPS a little bit which made it idle slightly higher, around 900 RPM, and it is better but it is still definitely there. As soon as I accelerate and it gets up to 1000 RPMs, the issue goes away. Is this symptomatic of a TPS issue? I also readjusted my throttle cables since I installed a new throttle cable, and they are moving freely and not putting any tension on the throttlebody at idle. It's completely drivable now, except that when you start it the idle bounces until you give it a little bit of pedal at which point it will probably idle cleanly, and it may stall all when coming to a complete stop in gear(stop light, etc). Any ideas?
 
dcbthr33 said:
Alright, fuel injectors came, and she is running WAY better. I metered the old ones and the new ones and they were all 14 ohms, so I'm guessing that #1 was leaking and making a too rich to fire condition.

Yes, the reason we ohm the injectors is to establish that the winding in the injectors solenoid coils are good. Meaning....the solenoid is 'capable' of operating, BUT...that doesn't mean there are no other physical/mechanical issues with an injector. A 'spray' test is the ONLY way to conclusively verify an injector is working properly. I've said time and time again....'Just because it clicks, doesn't mean it is working properly'.

The miss is now gone and the idle is perfect.

So you can likely conclude there was injector problems. You made the right move replacing them.

Only one problem remains – the pulsing idle issue. It will, on a half second interval, jump between 600 RPM down to 200 RPM and stall. It does not do it all the time; when it's not doing it, it idles perfectly. It seems to do it worse from a cold start, and in gear. If I unplug the TPS, it does not seem to do it either but then it idles close to 1000rpm and wont downshift. I adjusted the TPS a little bit which made it idle slightly higher, around 900 RPM, and it is better but it is still definitely there. As soon as I accelerate and it gets up to 1000 RPMs, the issue goes away. Is this symptomatic of a TPS issue? I also readjusted my throttle cables since I installed a new throttle cable, and they are moving freely and not putting any tension on the throttlebody at idle. It's completely drivable now, except that when you start it the idle bounces until you give it a little bit of pedal at which point it will probably idle cleanly, and it may stall all when coming to a complete stop in gear(stop light, etc). Any ideas?

I'd be looking at the TPS and its circuit. Also your Idle Air Control. IMO...this would be the next logical step, although there are other reasons for the symptoms you are experiencing. Be patient and don't become discouraged, you'll get this figured out.
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^^^^^ expand for reply
 
Update - it was the air flow meter. When I got the truck, it had a 22250-65010 on it, and when my whole saga started I noticed it wasn't the correct part for my truck(size mismatch at air box cover mount) so I thought this might be the issue and I got a "refurbished" correct one off of eBay(only plac si could find it). I had some trepidation about it since it looked like they spray painted it and the flapper wasn't super smooth, but since it didn't fix my problem and I went all in on this rebuild I didn't even think about it being bad. Swapped back to the old one just to try elimination and it's wayyyyyy better. Next question- can I leave the 22250-65010 ( from a 4Runner maybe?)on there, or is that a long term issue? It was on the truck when I got it and I ran it like that for 6 months since I didn't realize it wasn't correct. Any idea where I can get a correct one if it's not advisable to run that one? I'm taking a 500 mile trip tomorrow so I'm glad I found it - hopefully she runs like a top! Going down to Cape Lookout which is an off-road dream - I'll get some pictures!
 
I read this on a used parts web site, but i don't know if their information is correct or not. They said that the air flow meter, P/N 22250-74220 used on the 1/1990, to 6/1995 Toyota MR2, will work as a replacement for the air flow meter, P/N 22250 66010 used on the 8/1992, to 1/1995 Land Cruiser. Maybe Beno, or CDan will chime in letting us know if this is true or not.
 
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