Spark, But No Start

[mpgvh]

hey guys, after washing my "88 pathfinder, i washed under the hood just a bit-- truck ran for about 30 seconds, then sputtered & died on the side of the road. after towing to my brothers, I see there is spark going to the plug. I checked codes, & got 3 green blinks, then a long pause, and a red blink-- this is 31, which is Ecm? so, where is the Ecm, & what do i do with it, replace it? thanks for any help, I want my truck back!

[Slick]

the ecm is what we usually call the ECU....... it's your computer that you checked the codes on

[mpgvh]

the ecm is what we usually call the ECU....... it's your computer that you checked the codes on

would this mean the ECM needs replacing?

[GhostPath]

would this mean the ECM needs replacing?

 

More likely that you got water in some sensor or connector and it's making the ECU angry.

 

You'll want to dry out the car before trying to determine anything else - otherwise, replacing the ECU might result in another burned out ECU.

[mpgvh]

More likely that you got water in some sensor or connector and it's making the ECU angry.

 

You'll want to dry out the car before trying to determine anything else - otherwise, replacing the ECU might result in another burned out ECU.

o.k., went to the junkyard & found a pathfinder with a vg30 engine like mine, i could not tell what year, but it was a first. gen. this ECU has a '53' stamped on top, mine has a '10'. connections look dry, so i try to start the truck, & nothing. I try to check codes on this junkyard ECU<, & it doesn't light up at all, it is just totally dead? I put my old one back in, & the same codes-- 3 green flashes, a long puse, & then 1 red flash. So my question is, did i just happen to pick a dead ECU? do the numbers (53 vs. 10) mean anything? also, this truck was an automatic, mine is a stick-- does that matter? sorry for the rambling, but my frustration is rising. thanks again for any input

[unccpathfinder]

IIRC the 53 and 10 dont matter...its the other numbers that matter...sorry to hear about the ECU...the JY will most likely not take it back and say that "you were the result of it not working" this may or may not be true...

 

i do happen to have a good ECU laying around out of an 87 (MT) that I would be willing to sale...its for a Ca pathfinder (which doesnt mean a whole lot just some different fuel maps but if u're in cali thats a plus)

 

 

mine is a:

52

2371042G00

MECS-G200 01 6715

[mpgvh]

IIRC the 53 and 10 dont matter...its the other numbers that matter...sorry to hear about the ECU...the JY will most likely not take it back and say that "you were the result of it not working" this may or may not be true...

 

i do happen to have a good ECU laying around out of an 87 (MT) that I would be willing to sale...its for a Ca pathfinder (which doesnt mean a whole lot just some different fuel maps but if u're in cali thats a plus)

mine is a:

52

2371042G00

MECS-G200 01 6715

apparently i was reading the codes wrong- red lights are 10, & green are one. so, if i get one red blink, & 3 green ones, i get a 13--temperature sensor malfunction? why would this prevent my truck from starting? the truck will backfire (flame out throught the throttle body!) is it possible for the belt to 'jump'? once again, thaks for any input

[GhostPath]

apparently i was reading the codes wrong- red lights are 10, & green are one. so, if i get one red blink, & 3 green ones, i get a 13--temperature sensor malfunction? why would this prevent my truck from starting? the truck will backfire (flame out throught the throttle body!) is it possible for the belt to 'jump'? once again, thaks for any input

 

 

Sounds like you got water in the coolant temperature sensor or connection to same. Common problem. What it does is tell the computer how cold the engine is, so it can calculate how much fuel to give the engine. If radically far off or out of operational range, it won't know how much fuel to inject.

 

It is possible for an old or improperly installed belt to jump time.

[mpgvh]

Sounds like you got water in the coolant temperature sensor or connection to same. Common problem. What it does is tell the computer how cold the engine is, so it can calculate how much fuel to give the engine. If radically far off or out of operational range, it won't know how much fuel to inject.

 

It is possible for an old or improperly installed belt to jump time.

the sensor, is that the one located near the front of the throttle body?

[GhostPath]

the sensor, is that the one located near the front of the throttle body?

 

I do not know where it is on the TBI trucks, but if you wait a minute, I'll post up a pic of where it is on the MPFI truck - I suspect it's probably in the same place.

[GhostPath]

 

 

That's the water outlet. The black sensor screwed into it is the sensor for the gauge. The yellow one (may be another color if it's original) is the EFI coolant temp sensor and the one that we're discussing.

[88pathoffroad]

The CHTS for the VG30i is in a different location, but very close. It's in the middle of the t-belt cover on the front of the engine just to the right and below the thermostat housing. It's tough to get to. I don't know why that would prevent the engine from starting, though. When it's cold it should run in open-loop mode and not use input from the sensors until it warms up.

 

Have you pulled your distributor cap and checked for water inside?

[GhostPath]

The CHTS for the VG30i is in a different location, but very close. It's in the middle of the t-belt cover on the front of the engine just to the right and below the thermostat housing. It's tough to get to. I don't know why that would prevent the engine from starting, though. When it's cold it should run in open-loop mode and not use input from the sensors until it warms up.

 

Have you pulled your distributor cap and checked for water inside?

 

Um.... how do you think the computer tells when the engine has warmed up? That sensor, that's how. That also tells it how much fuel to feed on a cold start.

 

The only sensor it ignores in open loop is the oxygen sensor.

[94extreme]

Sounds like you got water in the coolant temperature sensor or connection to same. Common problem. What it does is tell the computer how cold the engine is, so it can calculate how much fuel to give the engine. If radically far off or out of operational range, it won't know how much fuel to inject.

 

It is possible for an old or improperly installed belt to jump time.

 

 

on it!

 

 

 

 

and it's been 3 days since the original post so, does it run yet?

[unccpathfinder]

Um.... how do you think the computer tells when the engine has warmed up? That sensor, that's how. That also tells it how much fuel to feed on a cold start.

 

The only sensor it ignores in open loop is the oxygen sensor.

 

From my experiences it runs on open loop for a set time not temp range...when i did my swap and didnt have a lot of stuff hooked up it would run for like 3 or 4 mins without any SES lights and then they would come on

[88pathoffroad]

Um.... how do you think the computer tells when the engine has warmed up? That sensor, that's how. That also tells it how much fuel to feed on a cold start.

 

The only sensor it ignores in open loop is the oxygen sensor.

 

Mmhmmmm, interesting. I've been wrong before. *shrug*

[mpgvh]

on it!

and it's been 3 days since the original post so, does it run yet?

o.k., i conceded & had the truck towed to a foreign auto garage. The problem was a bad ground connection on a wiring harness, near the passenger side kickpanel (the man who worked on my car spoke very broken english, i did want to press for what the problem was) & this still doesn't explain the temp sensor code, but the truck does run now ($200, plus $50 for the tow ) on a side note, it seems to have lost a lot of power, not that it was a ferrari before, & I hear on occasional backfire. I guess I should just be grateful the truck runs? thanks you all for the input regardless, & I hope this post may help someone down the line --marty