Replaced engine, no spark

I have a 1998 Toyota Tacoma with a 2.4L 4 cyl engine. Last weekend my truck died on me. My neighbor told me that if I found a new engine, he would help me replace it. Well, i found a complete engine at a junk yard that gives a 90 day warranty. We have the engine swapped out, everything reinstalled/reconnected, but it won't start. The engine turns over, but there appears to be no spark. I pulled plug #1 out and held to the engine, no spark. We swapped plugs, plug cables, the 2 boxes that the plug wires go into and still no spark. I'm at a loss. He's very good with mechanical issues but when it comes to the electrical side he isn't so good. I was hoping someone would have an idea for me, other than take it to toyota :)

Thanks! chrisw669 (at) gmail (dot) com

Reply to
chrisw669
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First off, why did the old engine die? You don't say why.

If it threw a rod through the block, that's one thing. But if it just quit running on you and you can't point to a cause, that's a different story entirely - you may have a problem that had nothing to do with the part you replaced, IE the engine.

If you reused the old distributor, coil and ignitor, plug wires, wiring harnessers, injectors, etc. it could be a failure on the car. Bad electric fuel pump, bad fuel pressure regulator shunting it all back to the tank, even an ignition switch or computer/sensor failure.

You need fuel, air, compression and spark, each at the right times, or nothing happens.

To eliminate fuel give it a /SMALL/ shot of Starting Fluid (Ether) or Propane (from a hand torch) down the air intake, and see if it tries to start - if it sputters and tries to run, you have a fuel related problem.

A timing light will show if you're getting spark at roughly the right time. If there's no compression the cranking will be way too fast and sound all wrong.

You might have to get a pro to take a look - paying for an hour's help getting it running is much better than tearing your hair out for a week, and changing a bunch of perfectly good parts by guessing at the problem.

Oh, and even if you have a "new" R-motor, if the new old engine is high miles check the timing set on it - 100K and up (usually around

200K) the chain tensioner goes bad, and the slack timing chain chews through the timing cover and dumps all the coolant into the engine oil. This is not good...

Good news is that the timing chain will rattle and bang a lot as it goes slack, it gives you a lot of warning if you listen for it.

Avoid that 'early failure', and the engine can be good for 300K to

500K, though you might need head and valve work before the bottom end dies of old age.

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Reply to
Bruce L. Bergman

engine die? You don't say why.

Sorry, it threw a rod, I guess "died" was a little vague. We tried the propane down the air intake and nothing happened. I don't have a timing light, but i thought that you could hold the spark plug to the block (where's theres a good ground) and when you turn the engine over you will see a spark (timed or not). I'll try to get my hands on a timing light to see for sure.

Could it possibly be the crankshaft or camshaft sensors? I read where they both have an effect on the spark.

My last resort i guess will be a pro, i appreciate their experience but when your short on cash, you do what you have to... :)

Reply to
chrisw669

What would cause such a young engine to throw a rod?

Reply to
JoeSpareBedroom

messagenews: snipped-for-privacy@4ax.com...

a young engine to throw a rod?

It had 290k miles on it.

Reply to
chrisw669

OK. Even so, what caused a thrown rod?

Reply to
JoeSpareBedroom

messagenews: snipped-for-privacy@a75g2000cwd.googlegroups.com...

I honestly don't know. I didn't bother getting anyone to give me a good diagnostic, the mechanic at the shop i originally had it towed to told me i'd be better of getting the engine replaced. That's when my neighbor said he could help me for much less.

I did a bit more troubleshooting: I unplugged the harness from one of the coils, checked for voltage in the left most wire with the key on which it had, then i connected a light probe to the positive battery terminal, plugged the light probe in the second to the left wire (it lit very dimly), tried cranking the engine (the light is supposed to blink) and nothing happened. The light probe stayed lit very dimly. I checked the voltage with a meter and it read about 6volts. This goes against what i've been able to find on how it's supposed to work.

Reply to
chrisw669

Is the engine yourve installed exactly the same? I came unstuck installing a different year motor into a car and found that they had a series change and teh wireing harness was slightly different, cost me $200 for the auto sparky to find the reason why the damn thing wouldnt rev normally. Two wires transposed in a plug set and it was fixed. Not that Mazda wouldve told us that eh.

Reply to
Scotty

Well, it's the same engine, but from the numbers on the top, i would say that it's a different series. Almost looks like the engine is a little older than the one that was original to the truck.

Reply to
chrisw669

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