Riddle me this...won't start

[dynomatt]

A couple of mates run a small workshop and have a 95 in that won't run.

The story goes that it was driving along fine, then just up and died.

Has sat at one small time mechanic since October last year with no joy (and no indication of what they did...if anything).

It was towed to my mates who diagnosed a dead fuel pump. Have replaced it, but now it won't go.

I checked the codes this morning and there are none...none at all. It now starts briefly (like 1-2 seconds) then dies and can't be started again until the next day. This all sounds like it's flooded to me.

So, they are pulling out the plugs to replace them all, but I'm wondering if any of you have had this problem before?

Matt

[sperry]

I wonder about the MAF sensor.

My car did some goofy stuff when the MAF went bad. Slapped a new one on there and life was good immediately. 'Course, my car would run great, then randomly die, then start back up after a few tries... not die for a day at a time.

But it's food for thought. You might want to hit the MAF with some cleaner and see if it improves the situation.

[log1call]

They should check that the ecu is getting (and keeping),power to all the places it is meant to.

The main relay can give symptoms like that. they get burnt contacts and run untill the resistance causes more heat and then they die out till they cool off again... and it sets no trouble codes. Some times they start within seconds, sometimes they start bucking as the power turns on and off again, and sometimes it takes hours before they will start again..

[dynomatt]

Thanks guys...I have a spare MAF and also I think a main relay.

Wasn't aware that the main relay was temperamental.

[oab_au]

Originally Posted by dynomatt

A couple of mates run a small workshop and have a 95 in that won't run.

The story goes that it was driving along fine, then just up and died.

Has sat at one small time mechanic since October last year with no joy (and no indication of what they did...if anything).

It was towed to my mates who diagnosed a dead fuel pump. Have replaced it, but now it won't go.

I checked the codes this morning and there are none...none at all. It now starts briefly (like 1-2 seconds) then dies and can't be started again until the next day. This all sounds like it's flooded to me.

So, they are pulling out the plugs to replace them all, but I'm wondering if any of you have had this problem before?

Matt

This isn't your 95, is it?.

I don't think it would be flooded Matt, you would smell it in a small shop, and twice as bad, when it did run for a couple of seconds.

As it runs, it must have fuel and spark for a while, so it has to be running out of one of them.
It sounds like it is running out of fuel. The plugs will tell, but I would check that there is pressure up at the injector rails. The regulator may be bleeding the pressure off, or there may be a mud wasp nest in the line.

Harvey.

[dynomatt]

Not mine Harvey...a nice green one.

Running out of fuel was my initial thoughts.

I hardwired the pump temporarily, but wonder if it had since been flooded.

How would it run out of spark? Cranks sensors? surely they would spit out a code.

Matt

[TomsSVX]

floor it. See if she fires with the accelerator on the floor pan. This is typical of a bad CTS.

Otherwise I would check MAF, CAS1, cam angle 2... You have a scope at your disposal??

Tom

[oab_au]

Originally Posted by dynomatt

Not mine Harvey...a nice green one.

Running out of fuel was my initial thoughts.

I hardwired the pump temporarily, but wonder if it had since been flooded.

How would it run out of spark? Cranks sensors? surely they would spit out a code.

Matt

Yes mate thats why I think it is fuel. The pump may be working, but there may be no pressure. If it was standing for a while, it could have a wasp nest mud, sticking the regulator.

Harvey.

[dynomatt]

Thanks guys,

Tom...CTS? Yes they have a scope. Wouldn't sensors throw a code though?

Harvey, as far as I know, it hasn't been standing. Has been a daily driver for some time. That's not to say it hasn't gunked up from something else.

Cheers,
matt

[TomsSVX]

CTS= Coolant temp sensor

If the CTS is bad it reads subzero temps in the ECU. On warm & hot days it adds too much fuel for the amount of air. So, crack the throttle plates... Might fire for you. Also make sure the fuel lines are not mixed up on the fuel pump

Tom

[oab_au]

Originally Posted by dynomatt

Thanks guys,

Tom...CTS? Yes they have a scope. Wouldn't sensors throw a code though?

Harvey, as far as I know, it hasn't been standing. Has been a daily driver for some time. That's not to say it hasn't gunked up from something else.

Cheers,
matt

I guess Tom thinks it's cold there in Canberra.

OK lets know what you find.

Harvey.

[TomsSVX]

Originally Posted by dynomatt

Thanks guys,

Tom...CTS? Yes they have a scope. Wouldn't sensors throw a code though?

Harvey, as far as I know, it hasn't been standing. Has been a daily driver for some time. That's not to say it hasn't gunked up from something else.

Cheers,
matt

Originally Posted by TomsSVX

CTS= Coolant temp sensor

If the CTS is bad it reads subzero temps in the ECU. On warm & hot days it adds too much fuel for the amount of air. So, crack the throttle plates... Might fire for you. Also make sure the fuel lines are not mixed up on the fuel pump

Tom

Originally Posted by oab_au

I guess Tom thinks it's cold there in Canberra.

OK lets know what you find.

Harvey.

Reading is good mmmkay?

Tom

[dynomatt]

Hi guys,

Thanks...CTS will be checked. We checked the fuel pump lines...when disconnected, (and the pump is running) it pours out the correct line (eg with the filter)...so hopefully that's correct.

What does the ECU use to keep the pump running? I assume it finds a CAS reading and says the engine is running? Keep pumping?

Matt

[TomsSVX]

Yes. But the coils will not fire without a CAS signal.

Tom

[svxfiles]

Also remove the O2 sensors.
Let them stay electricly connected, but let them hang there.
YT and Harvey know why!