Fuel injectors have low than spec resistance

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C

cold

10 Year
Joined
Feb 2, 2014
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5
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I'm restoring LX 450. 1997. It has 530k miles on its clock. The engine was almost dead - worn out rings, etc. It was smoking as a steamer. Big plus - not rusty.

Now the engine has new short block, head, camshafts, valves, all other running parts. All what is above the head cover, including fuel injectors, wires, most of the sensors migrated from the old engine. After all parts were installed, the engine turned on with first several cranks.

Then came a big disappointment. It constantly emits whitish smock even after it reaches its normal working temperature. Smells nasty, but there is no sweet or burnt oil in it. The closest would be - smells like when one drives behind a sh*tty old motorcycle.

I pulled out plugs (they are new, FSM recommended maker) - they smell gasoline, a bit wet between the plug and its washer. Must add, I'm diesel only guy in my whole previous life, so like a blind puppy with a gas engine. Probably, important detail, the gas tank still has gas inherited from PO. Can guess, the content is more than a year old.

The injectors have 12.4 ohms resistance v/s 13.4 - 14.2 ohms recommended by FSM. The injectors have been inspected by specialized shop. The verdict was 'good to go'. But FSM says 'replace injectors with resistance below 13.4.

Any opinion how strict are FSM's requirement in this case?
 
Where the injector clips replaced? Running good besides the smoke? Lots of power?
 
OEM new injectors?
 
The engine runs smoothly, almost purring. But aurally, there are barely noticeable interruptions. I haven’t driven it yet, the front axle is waiting for spare parts to arrive. I connected the scanner, not a single error code, but the engine ran for no more than 40 minutes. Then the stench became unbearable.

The wires were inherited from the old engine; the connectors on the injectors were not changed. I looked at the report on the maintenance of injectors - 5 injectors 13.9 ohms, 1 - 14.0.

Perhaps my $40 tester is lying, but my measurements are exactly the same for all 6 injectors. The injector tester will arrive tomorrow. At least I'll visually check how they work.

OEM new injectors ~ 1200. Can't justify so far.
 
cold said:
The engine runs smoothly, almost purring. But aurally, there are barely noticeable interruptions. I haven’t driven it yet, the front axle is waiting for spare parts to arrive. I connected the scanner, not a single error code, but the engine ran for no more than 40 minutes. Then the stench became unbearable.

The wires were inherited from the old engine; the connectors on the injectors were not changed. I looked at the report on the maintenance of injectors - 5 injectors 13.9 ohms, 1 - 14.0.

Perhaps my $40 tester is lying, but my measurements are exactly the same for all 6 injectors. The injector tester will arrive tomorrow. At least I'll visually check how they work.

OEM new injectors ~ 1200. Can't justify so far.
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Cheap multi-meters aren't particularly accurate down in low ohms ranges like that. I would trust the shop before I trusted a cheap meter.
 
Marvelicious said:
Cheap multi-meters aren't particularly accurate down in low ohms ranges like that. I would trust the shop before I trusted a cheap meter.
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Thought so about my multi-m. I will phase out injector version after I run tests on them. And see for sure they are not leaking.

My plan is to check up sensors installed to the head (by FSM). Should have done it while the engine was out, but..
 
Dug the forum for similar cases yesterday. Found several, but people obviously loose interest to their own topic after the issue has resolved, or do they send their unfortunate TLCs to the scrap-yard after loosing hope to fix the issue?
 
cold said:
Dug the forum for similar cases yesterday. Found several, but people obviously loose interest to their own topic after the issue has resolved, or do they send their unfortunate TLCs to the scrap-yard after loosing hope to fix the issue?
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Honestly, I think you'd be hard pressed to find a vehicle this old with a higher percentage of vehicles still driving around.

It's still worth checking, especially since you have a tester on the way, but I'm guessing your injectors are fine. It sounds like you say the plugs were ALL wet? Seems extremely unlikely that all the injectors would be sticking or leaking after the shop said they tested okay. I think you're probably looking at something else.

Ah, just saw your update. Faulty MAF certainly could do it!

Also, you might want to eliminate that old gas as a factor before you get super critical.
 
There is a slight learning that needs to happen after some drive cycles. I have never seen or heard of a bad MAF from a 95-97 might just need cleaned. If your clips didn’t break on the injectors I see no reason to replace those. Might just need to be driven??
 
Stop Sniffing it and take it out for a Good Drive then Report back here. I have an Inclination the Truck is Good.
You can check the Coolant for Free with Autozone Kit.
You can Check the Oil for $45 from Blackstone.
 
I suspect that MAF has been already replaced. It has several hand-written white marker numbers on it. Obviously - a used one. I will try to use some carb cleaner on its coils. But is there a hope it will help in a case of broken connection?
 
cold said:
I suspect that MAF has been already replaced. It has several hand-written white marker numbers on it. Obviously - a used one. I will try to use some carb cleaner on its coils. But is there a hope it will help in a case of broken connection?
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Are you getting error codes?
Did you follow the FSM for checking the MAF?
What "coils" are you referring to?

With regards to the injector resistance values, you're reading across a coil. Coils can open or short. They don't slightly change resistance.
As previously stated, inexpensive meters are typically not accurate when reading low resistances.
In any case, I wouldn't be concerned with those injectors. You can always send them out to Injector Masters for rebuilding and flow testing.
injectormasters.com
 
A half of carb cleaner can says: "Still zero resistance between THA and E2 terminals of MAF".
 
FWIW it's probably safer to use MAF cleaner (Hexane) to clean the wires of a MAF, Carb cleaner has much stronger solvents (Toluene, Acetone, ---)

If your MAF is dead you could find a used part in the Classified section (Parts and Parting out) on this Form. More likely it's still good versus an unknown part from a Salvage yard.
 
Kernal said:
you could find a used part in the Classified section (Parts and Parting out) on this Form. More likely it's still good versus an unknown part from a Salvage yard.
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Bummer, bought used from ebay already. Upd: did not find any in the Classified.
 
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Fleabay is a big kerapp shoot. There's always someone parting out their 80 or swapping engines on MUD, maybe go back and read through
a bunch of for sale and parting threads ie: it might not say MAF for sale in the title.

Someone listed a MAF just a couple of weeks ago, in TN IIRC.
 
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