Engine 850: B5252S/2.4/10v: MAFF Senser ?

[stevepcar]

Been working on trying to fix my project 850 T5 & then my everyday car 1995 850 10V B5252S 164,000 miles that has never let me down in 10 years & 45,000 miles refused to start. The engine turns over sweetly, I can smell fuel & there is a good spark to no 5 spark plug. I ran the codes & got 1:2:2, on the Fenix 5.2 system this means Intake air temperature sensor signal absent or faulty. Can this cause the car not to start? I have located it in the air intake cover & it is similar in appearance to a MAFF sensor, as fitted to the T5, only much smaller. Anybody any ideas?

[stevepcar]

Ref this post can I clear the air temp intake sensor with MAFF cleaner?

[Clan]

Originally Posted by stevepcar

Ref this post can I clear the air temp intake sensor with MAFF cleaner?

Yes , safe to clean an air intake temperature sensor , but it won't be dirty being fed with clean filtered air , even if it was caked with dirt it will still measure temperature , there may be a few seconds before the correct temperature soaks through though .

[stevepcar]

Thanks I will try cleaning it. I have tried to start it several times and it does fire a couple of times once I release the key. Does that ring a bell with anybody?

[Clan]

Originally Posted by stevepcar

Thanks I will try cleaning it. I have tried to start it several times and it does fire a couple of times once I release the key. Does that ring a bell with anybody?

low fuel pressure ?

[stevepcar]

Well I cleaned the Air Intake Temp Sensor, ran a bench check to see if it was behaving as it should & it did, ie the resistance fell as I heated it up with a hair dryer. So put it back in car ran codes & got 1:1:1 so all ok . But car still would not start. So looked at distributor and rotor arm: all a bit worn, but serviceable so ordered new parts as a it needs them. Decided to swap coil from my 850 T5
while I was waiting for parts. It didn't make any difference, but the car did try to start once I had released the key. It ran on a few times & white smoke (smelled like exhaust) came out from the front of the engine near the intake manifold at the end furthest from the dist.
I have no idea what is causing smoke to belch from the front of the engine. It seems serious though. I ran codes and still nothing showing up.
The car is blocking my driveway at the moment so I could really do with some advice on what to look for. Hope someone can help.

[stevepcar]

Further to this post, could the white smoke be coming from the PCV box? Would a clogged/ split one cause a non-start?

[Clan]

Originally Posted by stevepcar

Further to this post, could the white smoke be coming from the PCV box? Would a clogged/ split one cause a non-start?

No it wont affect starting , have you got spark at the plugs ?

I did once have a strange case like yours on an 850 many years ago , to cut a long story short it was the routing of the main battery cable from battery to starter past the throttle . It was causing a magnetic field interfering with the flywheel sensor signal . just moving the cable 2 inches to one side fixed it .

[stevepcar]

Yes I do have spark at the plugs and just in case it was not strong enough, I swapped the colis from my T5 & it still wouldn't fire up, although it did try & belched white exhaust smelling smoke from the front of the engine.
I am testing the fuel pump & relay today, in case I am not getting enough fuel.

[stevepcar]

Well are't I dumb. No problem with fuel system, but re-gapping the spark plugs & replacing the HT lead from the Coil to distributor & the old beast fired up. Just goes to show that I should've check the easy & obvious things first!!! Just cos' I got a spark doesn't mean it was adequate to start the car.
I do need to do the PCV system though, its already made the crankshaft oil seal leak, leaked oil under the spark plug cover & the glove fills up when held over the oil filler.