Kiroshu

No-Spark...

Does the engine crank over faster than normal...?

Possible damaged/broken timing belt not allowing distributor to rotate thus... "No spark" condition.

Remove Distributor Cap and crank engine if distributor rotor does not rotate you have found your cause of "no spark."

Its possible for distributors them selves to break... but very rare.

SpoiledAdoptedLab

Thank you all for sharing your knowledge...

I, too, thought that maybe the reason it won't start is due to the fact that it isn't getting fuel because the fuel pump is dead, but what do I know...however, my husband thought I was crazy and said there is absolutely no way the bad fuel pump is causing it to not start. At this point, he thinks that it is the ignition...any knowledge regarding replacing the ignition would be greatly appreciated!

scope103

Sigh ... You're not going to "replace the ignition." Why don't you have your "husband" tell us why he thinks that it is the ignition. I'm sure he can type. Did he, oh, put a timing light on each plug wire and find none of them were firing?

The manual http://personal.utulsa.edu/~nathan-b.../ignition.html tells us everything we know about testing ignition circuits.

j2the-e

It seems unlikely that multiple problems all happened at the same time.
Did you check for fuel using the above tests by jumping fp and b+?
Does the check engine light turn on momentarily when the key is turned on?
Are there currently any codes?
Does the engine sound normal while cranking? -smooth and consistent, no flat spots?

d.ammons11

Thanks for the clarification on this Scope103. That was my Bronco that would prime the fuel system. Yes jumping the B+ and FP terminals in the diagnostic plug is the best way to test the fuel pump. But if there's still no spark then that should be fixed first. Has your husband tested every plug for spark will holding it against the engine for a good ground. I've never had this problem before so I don't know exactly how to test it, but I'm guessing as others have suggested using a timing light is going to be necessary instead of blindly replacing ignition parts.

Capt B

Check the large 30 amp fuse in the fuse panel under the hood. This happened to my son's 91 Runner. Would crank no fire or fuel. I think the fuse is pink in colour. had it running for a bit then blew 15 amp EFI fuse. We suspect fuel pump is grounding out now.

SpoiledAdoptedLab

UPDATE...Frustration won - we loaded the damn thing on the trailer and took it to a reputable Toyota mechanic. It's cost us $100 and they still have no idea why the damn thing won't start! It won't throw any codes because the check engine light is not on, so they say. Any ideas?????

This is a strange question...is it possible for a mechanic that knows quite a bit about vehicles, to do something to my truck to make it not start? Something that another mechanic wouldn't think to check because whatever the person did to it was something that wouldn't have broken on it's own. Like loosened a wire, removed a small part, etc. The reason I ask is because our daughters boyfriend has worked on my truck for the last 4 years and has never came across anything that he couldn't fix. This boyfriend is now disgruntled with us because we told our daughter things about him that he didn't want her to know...I'm very suspicious about him. Could this be possible?

PLEASE HELP!!!! THANK YOU!!!

j2the-e

You said no check engine light. Does that mean no codes, or no light at all?

bbrideau

If the light doesn't come on at all it either means. wiring to ecu is shorted out or your ecu itself has given up the ghost so to speak.

RSR

Barring a hidden kill switch you weren't aware of, it's doubtful. Kill switches would likely go to starter, spark, fuel, or ECM and your mechanic would probably find if looking at them closerly -- seeing wire loom opened/retaped especially... Relatively simple electrical on these rigs w/ so much being controlled by vacuum.

Any chance of failed security alarm on the rig?

One thing to consider on this truck is stock wiring has a couple of fusible links that go if voltage runs too high. Essentially, they burn up and need replaced. Not a tampering issue but one to consider.

Was the distributor ever removed during your troubleshoot process? If so, it being 180* off could be the cause of a failed starter too. Or a removing distributor cap and rotor and fiddling w/ the wiring/sensors might cause this problem but I'm not sure. Oh, and don't forget the plunger thing on the cap -- relatively easy to dislodge taht if not careful on the install, which will affect your spark.

Failure to start at all is likely a fuel or spark issue IMO.

scope103

No. (Well anything is possible; let's just call this incredibly unlikely.)

Mechanics (including you) don't find problems by "looking in the usual places." They start at the end and work backwards. Hidden kill switch? You start by checking if there is spark. Disconnected injector wire? Check to see if you have a wet plug. Rotated cam shaft? Check for compression first.

All gasoline engines need fuel, air, spark. That's where we start.

SpoiledAdoptedLab

Well, the repair shop finally got codes of 22, 24 and 31...the shop replaced the EFI coolant temperature sensor, it started right up and we put it on the trailer and brought it home. As per the shop mechanics instructions, my husband replaced the mass air flow sensor. Now it starts and runs fine with two exceptions, it will not shift into overdrive - you hit 50-55mph and the tachometer stays at 3000 rpm's, and the temperature gauge barely goes up at all even when the truck is totally warmed up. I'm just thrilled that it finally starts and that the acceleration problem is resolved!

Checked for codes again and got 24, 25, 31, 41, 42 and 43...while trying to clear the computer before running the code check, the OD and CEL would flash on the instrument panel, as well as, make a blue light on the remote starter device attached to the front windshield flash.

Any clues on what to address first? Could code 41-throttle position sensor, or code 42-vehicle speed sensor signal have anything to do with the shifting issue? I believe code 43-starter signal, has something to do with why the blue light flashes when starting the truck.

Any insight would be greatly appreciated!

RSR

First guess is bad thermostat... Or it could be they drained all the coolant and you have an air pocket at the thermostat that's not allowing it to open... Some tricks on here if you search.

j2the-e

Both TPS and VSS affect shift points

scope103

Do you have heat? You can't get overdrive with a cold engine, and if the temp gauge is not moving I'm with RSR. (The ECT and gauge and transmission all have their own sensors, so they're probably telling the truth and the coolant is staying cold.)

TPS? You're in luck! Since you have the A340H you can test the TPS right from the diagnostic connector. http://personal.utulsa.edu/~nathan-b...34electron.pdf (p. 128) None of this screwing around with feeler gauges.

SpoiledAdoptedLab

I do have heat, but barely...my husband changed the thermostat before it went to the shop for repairs...could the new thermostat have been defective? We'll start checking the throttle position sensor and the vehicle speed sensor. I'll update when we know more.

Does anyone know how difficult/easy it is to change either of these two sensors? I just checked out the price of these two sensors on ebay - would it be unwise to get either of these sensors from a 1993 4runner from the scrap yard?

Thanks again for all your help out there!!!

scope103

Before you do any of that, re-check the installation of the VAF (you have a VAF, not an MAF, that's nit-picking but they work differently). Both 24 and 31 (temp and VAF signal) come from the VAF assembly; something as simple as an electrical connector could cause those.

You have two speed sensors; the code refers (so far as I know) to VSS1, which also gives you speedometer (and odo and cruise). Did you lose those too? VSS1 is easy to replace, but not so easy to buy (about $250 at RockAuto).