XJNKY

Hello everybody.
Just to get a few things out of the way, this is my first post. I did in fact create an account just to ask this question. And I have searched extensively across the internet for answers, including here. I've found a couple similar situations, but never a conclusion.

So, here's my story. 1988 Pickup, 4x4, 22re, 5 speed. Rusted out crap pile revived from the dead. Bought it with rod knocking, 323K on the clock, and supposedly the 3rd engine in it. Bought it to tech my nephew how to work on cars, with the intent of giving/selling it to him when it was fixed. He was 16. He had zero interest, so I decided to fix it and just sell it. I'm coming up on 2 years into it, and still not driveable.

Short version, I bought a parts truck that was supposed to have a good 22r. It might have until they left the hood off and the carb uncovered. So I built an engine out of 2 bad ones.

It has KB +1.0mm 9.7:1 pistons
Moly rings
Bored 1.0mm over
Engnbldr 268 Torker cam
Doug Thorley header
Port matched intake
2.25" exhaust, all the way back, no Cat, Thrush welded
New Fuel pump/ strainer/bracket/filter/fuel line.
Taylor 8mm wires and Accel Supercoil. (bosch distributor cap and rotor)

Now, here's the problem. It wont restart hot (by hot, I mean at operating temperature). Will usually sit and idle until it's out of gas at operating temp. Revs like a chainsaw. But once you shut it off, it simply will not restart until it cools back down.

• It did great when I first got it running. But then on a test drive around the neighborhood, I parked it outside the garage, and it wouldn't restart to pull in. 30 minutes later, starts fine. Seemed like an odd anomaly. Tested it again the next day and it restarted fine hot.
• Couple weeks later (still a project, not really being driven), I drive it to the gas station down the street. Won't restart at the pump. Walk home, get truck and trailer. Go to retrieve it, and it starts fine. Tow it home.
• Do a bunch of reading, many opinions, no answers.Check codes. None. Read about VSS to the FPR being a potential cause. I drive it 15 miles out to my farm. Shut it off to check trail cameras and whatever. Go to restart. Won't fire. Pop the hood, pull vacuum line from VSV and bypass it, plumbing FPR straight to intake manifold. Fires right up. Problem solved!
• Just kidding. Does it again when I get home, with VSV still bypassed. I rehooked it after that.
• Check for spark when it's cranking but not firing. It's getting spark, but it's dull yellow. Replace coil with Accel Super Coil. Didn't help (but did give it more power when it is running). Definitely a bright blue spark now.
• Am given the suggestion that the Coolant temperature sensor may be bad, or that the cold start timing switch may be bad and flooding it by firing CSI when hot. Had checked a spark plug, was not fouled. And I broke the temp sensor on engine install and replaced it with a new one from Autozone.
• So I check codes, again, and now there's a 22. Bad coolant temperature sensor? Buy a new one from Oreilly's, install, unhook battery, rehook, start, code goes away.
• Try again the next day after work, won't restart hot. Grr...
• Try again the next day after work, but unhook the cold start injector after it has started to eliminate that as a possibility. It has no effect. Still won't start hot. Pull out the can of starting fluid, and it will start on it, and then sort of run after it runs out of it. It will rev fine, but won't idle very well. Give up for that day.
• Quit messing with engine for about a week and change bench seat out for buckets from a Scion TC. They're comfortable, but too tall, just FYI.
• Try to tackle engine again after that, starts cold, but idles like crap. Sounds like it has a nasty cam, and is dumping raw fuel. Check codes. Oops! I accidentally unhooked O2 sensor in the seat install. Easy fix. back to "normal"
• Do a lot of reading and asking in Facebook groups. No good ideas. Even tried leaving the gas cap loose because someone was convinced it was vapor locking.
• Confirm that fuel pump is coming on during no start. Even try it with Fp and B+ crossed to ensure it's on.
• I've now decided that it is simply not pulsing the injectors when trying to restart hot. (Injectors were not replaced, but were soaked and cleaned with carb cleaner and the 9v battery trick during engine build.) So I try to test that theory, but I only have a cheap autozone multimeter. Neither of my test lights flicker on the injector, but the meter shows the voltage dancing around when cold, and doing almost nothing when hot. (I assume the pule is so quick the light flickers too fast for me to see and the multimeter is just barely picking it up.
• So, what controls the injector pulse and spark? I measure air gap and resistance across distributor pickup coil. Air gap is in spec. Resistance is 540 Ohms. Spec is 140-180.
• Theory: The pickup coil is just on the ragged edge of still working. It's right behind the cooling fan. Resistance goes up with heat. Cooling fan keeps it just inside a functional level. As soon as I shut it off, it heat soaks, it goes outside range and won't provide signal. Why does it spark then? IDK, but it's out of spec so I replace it. Also replace EFI relay, just for giggles.
• New pickup coil from Rock Auto. Install. Set air gap at 0.010". Start it. Idles rough... very rough. Shut it off, measure new pickup coil. 0.2 ohms. Check again. 0.2 Ohms. WTF??? It's out of spec the other way. Drive around block. Feels like it's missing power. CEL flickers a bunch, but doesn't stay on. Pull in driveway. Letting it idle... roughly... and it start spewing steam. Shut off. I have coolant pooling on lower plenum. Source still TBD. Pull codes. 22. bad temperature sensor. How? Bad wiring?

No idea what to do here. Out of ideas. Plan to check continuity of sensor wiring, somehow, after I get the upper plenum off to find the coolant leak. Thought about replacing ignitor, but it's expensive and I don't want to just keep throwing parts at it. And I'm struggling to understand exactly how this system works in these trucks.

All relevant opinions and well educated guesses welcome.

Thank you.

XJNKY

And, just for giggles, the rest of the truck info.

• Engine also has Aisin oil pump, head shaved 0.012", premium everything. Cloyes HD timing set, new timing cover, crank turned, premium bearings.... I didn't cut any corners, mechanically.
• Trans, T case and rear end are from donor truck with 142K. Trans has new input bearing and seal. Clutch is a LUK supposedly HD. (Engine makes enough torque to slip it with 35's)
• Chevy 63 springs with Ruff Stuff kit, 6" shackles. Frame shortened 4". Wheelbase still stock
• Stock 4.10' gears, for now. Custom tube rear diff guard. Lock Right in rear. Shocks relocated on top of axle.
• Full custom tube/diamond plate bed, styled after All Pro bed. Used original rusty tailgate to skin a tube tailgate, with gate latches to hold it in place.
• Fugly but functional chase rack over the cab. It's a bit short on cargo room...
• LED trailer lights for tail lights
• Trail Gear winch plate in front with custom stinger bumper built around it. Reinforced mounts and D rings. Badlands 9K winch. Diamond plate fill-ins for bumper. Trailer light turn signals and 4"x6" LED pods.
• Custom tube flat fenders in front, plated with diamond plate and accented with LED trailer marker lights. Tied into slider bars that connect bed to fenders.
• Custom Ammo can gas door mounted under bed.
• AR grip a a shift knob
• Lots of patina, left by choice. (planning on shop truck decals on doors when done)
• IFS still, but 2" balljoint spacers and Pro Comp shocks in front. (looking to SAS if I ever get it to run right)
• Diamond plate floorboard (guess why...)
• Interco 35x12.50 LTB's that rub body at full turn, brand spankin new with the hairs still on them. Trailmaster cheapo D windows, 15x8, 3.75bs.
  
  I've got about $7800 worth of receipts in this TuRD.

scope103

Uh, thanks uncle X.


it sure sounds like vapor lock. Once the engine (actually, the fuel line) cools down the bubbles collapse and the pump can get the fuel to the rail. And vapor lock is what the fuel pressure-up is designed to address. By connecting the FPR to atmospheric (instead of engine vacuum) when the ECT reads high, it raises the pressure to the rail and pushes the fuel through. When you bypassed it, you lost that pressure increase. I suspect that it started then only because it took just enough time to cool off the fuel line.

I don't know a lot about the 22re, and even less about the 1988 models, but here's the '93 manual on that system: http://web.archive.org/web/201501160...ne/41fuelp.pdf

The next time you have a no-start situation, you might try just quickly disconnecting the vacuum line to the FPR. If it starts, you'll need to put the line back on (or it should flood).

XJNKY

Scope,

Thanks for the thoughts. I guess I should have said, after the VSV bypass failed to work again, I hooked it back up like I *think* it's supposed to be. But, I'll try the full disconnect and see if that helps. I've been chasing

I don't understand much about vapor lock. But I'm skeptical for a couple reasons. Maybe they're unfounded. When I shut it off, if I hit the key in the next 2-3 seconds it will cough back to life. Any longer than that, and it's a 30-40 minute wait. Can it really happen that quickly? Or is that even more evidence of a vapor lock theory? And does it not happen when running simply because the fuel is flowing fast enough to not have a chance to heat up?

Also, how does that synch with what appears to be a lack of injector pulse? I guess that's still a little iffy since I can't 100% confirm that to be the case.

Another thing is... The vacuum system is my best guess. It was pieced together from 2 engines, and the engine it came with was... well, it wasn't right. It was supposedly already the 3rd engine the truck had had in it. It was all kinds of jacked up. So I tried to rebuild it as best I could from diagrams and disassembly pictures, but by hard brackets don't match the diagram under the hood, and... well, it's a best guess.

Thanks again for your thoughts. I'll try your suggestion. What's that line from War Games? Something about urinating on a spark plug...

XJNKY

*Also... Nephew X was too lazy to get off the couch, and was pretty adamant about his disinterest in any part of the process. Just said his first car was going to be a Mustang GT, that he was apparently going to pay for with hopes and dreams. So, since the truck *looks* so cool now, there is a very real desire to go rub it in his lazy teenage face... if I could just get it to run...

scope103

Here's an article on Toyota Fuel systems, that discusses the pressure-up system: http://www.cygnusx1.net/Media/Supra/...taTech/h42.pdf

But like I said, what you describe sounds like vapor lock. It doesn't lock with the pump running (and air flowing over the fuel lines) because it doesn't get the chance to heat the fuel. And, it takes a few seconds for the now-heat-soaking engine to warm up the fuel lines and cause the bubbles to appear. If you crank the engine quickly, the fuel sitting in the lines is still cool.

It doesn't. The ECU suppresses the injector pulse when it doesn't receive the IGF signal from the igniter, but it waits a few revolutions so I wouldn't look at that for a no-start case. Of course, you could have a wonky IC in your ECU that just doesn't like heat, but that's not only unlikely, but just about impossible to confirm. If messing with the rail pressure doesn't get you anywhere, you can either invest in a set of " 'noid" lights, or carefully build one with an LED and 1K ohm resistor, to test for injector pulse. A multimeter is just doing it the hard way.

XJNKY

Sweet. Thank you again, for the thoughts and article. (Why can't I find these things? Google fu must be weak)

I had to google what a noid light was, but seems simple enough. I might even be able to sneak out into our electronics lab at work and piece one together.

One other question. If I jump the terminals to power the fuel pump... wouldn't that shove the hot fuel back towards the tank via the return line and mitigate a vapor lock condition? Because I've tried that, and it didn't help.

Also, I've been sitting here looking at injectors. I've had problems on a late model Jeep 4.0 with the injectors heat soaking before. So, even though they were getting pulse, they were barely letting fuel through. Of all the new parts I threw on this engine, the injectors are, to my knowledge, still 30 years old and 300K+ miles. (I put new O-rings on them at least...). I was just already way over budget.

Think there's any reason to bite that bullet when I have the plenum off? Apparently 1988 is a PITA because it's a 1 year part. So they cost about double what other years do.

scope103

I commend you for trying to be systematic in your search. Vapor lock was supposed to be "old-hat" 50 years ago (along with gas-line freeze), and yet some smart engineers in Japan were still dealing with in the mid-90s. The fuel pump runs as long as the key is to start, and yet that wasn't thought to be enough. Perhaps the fuel bubbles are sitting on top of the injectors, and won't squeeze through unless the rail pressure is raised. I have no idea, but it's not a hard hypothesis to check. Unlike most of your other concerns.

Injectors can be tested; I wouldn't replace one without putting it on a jig and seeing it fail. You're missing a lot of gas; I doubt a single bad injector would do it.

If you make your own 'noid light, remember that these injectors have one lead to 12v with key-on, and the injector is opened when the other lead is grounded. So don't get to excited when you find constant 12v on an injector lead. I think you have the low-impedance injectors with the big resistor bolted to the apron. I don't know much about the 1988, but there are others here who do.

XJNKY

Thank you. I do try to be systematic. I lose that at a certain frustration level. For reference, I've been fighting with this thing since about August. I've ran out of patience several times and had to walk away for a week or so at a time.

Also, excellent point about the likelihood of 4 injectors heat soaking at the same time. I did once have the low beams go out on a 94 Wrangler. I checked fuses, replaced the dimmer switch, chased wires... It finally turned out... both lights had just decided to burn out at the same time. The odds of which are... well, I don't know. But it baffled me.

XJNKY

Still nothing.

TLDR Summary: Vacuum to FPR made no difference. Will start with #1 injector unplugged, but not with it plugged in.


I made a noid light out of an incandescent 194 and socket I had laying around, based on some DIY info I found (fresh out of resistors this weekend, and radio shack has been gone like 5 years). It didn't work. Even with the engine running (on 3 cylinders). If I held either end to the throttle body to ground that end out while the other was plugged in, it would come on, but wouldn't come on just plugged in the socket.

BTW, I can really only get to the #1 injector...

So I got a set from Autozone (they have them in the loan-a-tool for $25, btw. OEM brand part# 127161).

I tried the "Bosch" style with the engine cold. It worked. Not quite what I was expecting. It really didn't flash cranking so much as it just started to glow as the engine started and ran. And it would get brighter if I revved it, but I didn't like doing that because... 3 cylinders... If I unplugged the coil so the engine wouldn't start, it wouldn't glow or blink, but I don't know if that's cause there's no pulse, or because it just isn't cranking fast enough without actually starting. (so in short, maybe the noid lights aren't working right. Videos I've seem have them flashing when cranking but not starting)

So, with that still questionable, I moved on. Started the truck, let it run for 15 minutes, until it finally wouldn't start back. Unplugged the FPR (to atmosphere), no change. Plugged it back to VSS. No change. Pulled injector#1 plug, noid light, crank, and it sputters to life. I think, well, it's had time to cool down (??) so I plug injector back up, crank to start to get it warmed back up again, and it won't start. Unplug injector, plug noid light back in again, and it starts. Plug injector back up, no start.

Thoroughly confused. I slammed the hood and walked away for the night. It is apparently getting a pulse... that the light won't show until it's running I've got to get these things back to Autozone.

Any new thoughts? Why unplugging an injector would make it start, but plugging it in would prevent it?

Also, here's a video of the noid coming to life with the engine, on try # 2:

RAD4Runner

CSI timer gets ground from the mounting threads. Make sure it's cleaned to bare, shiny metal and use no insulating sealant or teflon tape.

coryc85

Just noticed you were from KY, I was born and raised in Owensboro...go Wildcats!

Cleaning the CSI timer as Ray points out is good to do, but I'm skeptical that is the issue here since yours won't start when hot. When the truck does start and run, do you have a proper cold idle that then settles to a warm idle? Do you have an EGR connected? Are there any vacuum lines going to that bi metal switching valve screwed into the intake? Any vac leaks? Are there any stored codes? How is the O2 sensor?

I'm trying to think of things that may vary based on temperature.

XJNKY

I'm skeptical of the CSI or the timer also, as that system appears to be working properly.

I *had* a proper cold idle that turned into a proper warm idle. It is a little less smooth now seems to have degraded when I switched the distributor pickup coil. But, it's also part of a larger pattern of it just seeming to degrade overall, so it's hard to pin it directly on that one part.

EGR is all in place. Vacuum lines are... as mentioned before, best guess. It was pieced together from several engines, and I've seen 4 different vacuum diagrams for this year. So... ???

I don't know what bimetal valve you're referring to. Care to elaborate?

O2 sensor is brand new. Only issue with it is I stepped on the connector, and so, even though it is making solid connection, I have the connection wrapped in electrical tape to keep it together. It did come apart when i was swapping the seats, but it made itself known immediately. Currently working as it should.

Only code to date is a code 22, which is the CTS. And it seems to come and go. Might be looking at a broken wire in that harness(?) because it's the second new sensor I've put in.

Co_94_PU

iTrader: (-1)

"

• Try again the next day after work, but unhook the cold start injector after it has started to eliminate that as a possibility. It has no effect. Still won't start hot. Pull out the can of starting fluid, and it will start on it, and then sort of run after it runs out of it. It will rev fine, but won't idle very well. Give up for that day."

This says you have a fuel delivery problem. Combined with your hit and miss with the injector pulse. It's likely a bad wire in that main loom, they are known to go bad and it sat neglected so could have rodent damage. You also need to get that CTS signal worked out.

I don't like to recommend it but it might be time to cut that main loom open and see what is going on in there.

XJNKY

It did sit in a field for about a year waiting for me to get to it, after Nephew X refused to have any part of it. I, strangely, never saw any rodent signs, but I suppose that is possible. I'm personally more concerned about 30 year old wires that have suffered at least 3 engine swaps. They get brittle after a while...

As for digging into that harness... I'd just about rather pull a healthy tooth with rusty pliers...
But... maybe that's where I'm at.

I'm still perplexed about it starting on the noid light but not on the injector. I think I saw somewhere that the injector wiring was paired? Didn't fully understand it, but like they shared a ground (?). Could one injector be bad enough that when it gets heat soaked, the resistance goes too high, and thus disables another injector?

Sometimes when it's cranking and won't start, it'll give a little hiccup, but won't catch. Usually it's just nothing though. But it sputters to life on 3 cylinders. I would imagine it would be difficult to do so on 2.

I guess I need to yank the upper plenum, inspect the harness as best I can, and ohm the injectors...

RAD4Runner

Yes, yes, and yes...
There is/are a crimped splice(s) that join all negative sides of the injector together (red lines below). That harness is in very inhospitable environment. If I were to re-wire, I would re-route all wires that do not need to be there (like the 4WD and Back-up Light wiring), and wrap the remaining wires with a silicone insulator or something.

wallytoo

iTrader: (1)

in fact, all four injectors are tied together electrically, and they all fire together, not sequentially. the connector from, say, #1 can be swapped with #2, and the motor will run fine. same with swapping #2 with #3 or #4, etc. this is not theory, it is fact, and i've run mine successfully for thousands of miles with the connectors swapped to "different" injectors. makes no difference, unless you have a wiring problem between the connector and the splice points.

RAD4Runner

YUP. Schematic above shows it, so basically one could splice them all near the injectors where convenient and run one thick wire to the ECU and connect that same wire to both Pins 10 and 20 of the ECU.

O.P.,
If you could post pics of the wires from the injectors to that crimp, we would appreciate it; it would help other owners in the future.

XJNKY

First, thank you immensely for the diagram. And whoever stumbles across this in the future trying to figure this out thank you also.

It's been about 12 years since my last electronics class. I'll admit I struggle a little with wiring diagrams. So please bear with me.

Am I seeing that injector #1&2 are paired, and #3&4 are paired? But they all run to a common ground at #10 (or #20?). So the firing order is 1-3-4-2, right? So, when I have the noid light in #1, and it is closing that circuit, as is evident by the light coming on... it runs. But when I have it on the injector, it is refusing to start. So, hypothetically, could my #1 be suffering increased impedance (or, since these are DC, wouldn't it just be resistance? I always see it listed as impedance...), and basically taking #1 and #2 off line(?). Does that reasoning make sense? And it trying to run on just 2 cylinders... which, actually, the way it hits and misses when it does try to actually start, it like 2 hits in a row followed by 2 dead cranks...

If I could get to any other plugs, I'd throw a noid on them and see, but #1 is the only one I can reach (I have short arms but big hands. Makes it hard to get into tight places).

So, I'm thinking maybe checking resistance across each injector might be a step before cutting open the harness. (I really don't wan't want to do that...)

Another thing I'm not understanding from this diagram. If it pulses the injector by sending one side to ground... but they're paired, and it looks like all the grounds are tied together... how, exactly, does it control each injector individually? Is there a wasted injector pulse in this system? (*edit* maybe that's in the link Scope gave me. I didn't get all the way through it. Been skipping my homework...)

XJNKY

I couldn't keep up with updates. I guess you had answered that before I asked that.

Why would they do that though? So, you've basically got a fuel charge just sitting there waiting for a valve to open and pull it in?

I guess this was the early days... and still a little better atomization than the carb, but... seems crazy primitive.

Anyway, so, then, one dead injector, for instance, wouldn't short them all out.

I'm just still trying to figure out why it will start with one hooked to a noid, but wouldn't as soon as it was hooked back to the injector. Makes it all the more puzzling...