Intermittent Starting Issue MAF/VAF? (1 Viewer)

[NNVATXFJ80]

Hi All,

My FJ80 has recently developed an issue where it won't start consistently, especially if sitting for a few days. If I spray some starting fluid, it fires and runs fine. The time switch was replaced a few months ago, so I took it back to the shop just in case it was that, and they said the MAF has gone bad. I just wanted to make sure that made sense to everyone before dropping 650 on replacing it.

 

[NNVATXFJ80]

Also, how complicated is the replacement procedure if I bought a remanufactured unit for $150 and tried to do it myself?

 

[ajax1]

Well if you have a fj80 which is 91 92 years you have a vafm which you can’t buy new to my knowledge, if they undid the two screws where it plugs in then it is damaged more then likely. When mine went truck would stall but start and you would have to keep pedal going to it.
The 95 they 97 have a maf

 

[ajax1]

Fsm tells ya how to test with multi meter

 

[NNVATXFJ80]

How difficult was replacing the VAFM on yours? Any special tools or knowledge needed @ajax1

 

[ppc]

Replacing a VAF is a job. might take 10 minutes with no special tools, just the proper sized wrench or socket and a screw driver or needle nose to remove the clip securing the electrical connection. Do not remove the screws.

That said, what year is your vehicle and exactly how did you spray the starting fluid? Normally positive results with starting fluid indicates that the VAF is not the issue. It's possible the VAF has a fault not allowing the fuel pump to run. Before you spend a lot of money on parts you need to do more diagnosis. In oder to provide help you need to be very specific on what happens when you try to start as does it briefly fire and dies or just cranks.

 

[NNVATXFJ80]

So I just unscrewed the wing nut on the air cleaner and sprayed a shot in there. When it doesn't start, it just turns over but never really seems like it is starting to fire well. It may stumble for half a second, but nothing more. When it does start, it turns over several times and then runs fine. I pulled the cold start injector out and it has pressure at the injector, but it is not spraying. I checked the resistance on it, and it was at 3.8 ohms.

 

[CJF]

whole lot of wasted breath till we know what year it is...

 

[jonheld]

Took the words right out of my mouth...

 

[NNVATXFJ80]

My bad 1991 haha. The PO gave me a can of starting fluid and said use this if it ever doesn't start. 2 years and it started every single time until now.

 

[ppc]

Has there been any recent maintenance? I'm not familiar with "the time switch". Have you verified that there is no cracks on the underside of the intake tube. When was the last time spark plugs, wires, distributor cap and rotor were replaced? Start with the normal maintenance items and the simple things before replacing the high dollar parts without proper diagnostics.

 

[NNVATXFJ80]

So about 6 months ago, this shop replaced spark plugs, the distributor cap, rotor button, cold start injector time switch, coolant temperature sensor, and valve cover gasket.

 

[Technician1985]

Explain what it does in more detail. It has problems starting when cold?

 

[Technician1985]

You can connect both leads of the cold start timer plug to ground and it will think the engine is cold every time, might want to try that to confirm if your cold start switch is working or not.

 

[NNVATXFJ80]

Good call. I'll test that out this weekend.