re-cap: 1990 302

new plugs
new wires
new filters
.....failed air-care
engine hunts and stalls at idle. If I put it in neutral when I come to a stop, it won't stall, but still hunts. If I turn the steering wheel when idling, it usually stalls. ANY load at idle will stall it. Checked and reset the timing, no help. Was advised to change MAP Senser ($110!!!!!), no improvement.

Took it to a garage, mechanic put code reader on it and it wouldn't work. Gave a message "If no response in 60 seconds, see Ford Manual blah blah blah".

Mechanic said intake manifold is leaking, AND fuel is running too rich (black smoke) WTF?????? If air is getting through the intake manifold gasket, how could the fuel be rich? Too much air is lean is it not?

So I re-checked PCV, it's fine, but on the other side, the hose from the valve cover to the air filter box is sucking really hard. Should there be a ton of vacuum through this hose? I have no clue anymore. I'm losing my mind over EFI (I think, no wait, whatever.....)

So is this big sucking through the valve cover on the driver side causing black smoke and hunting/stalling?

This engine ran fantastically before I changed the plugs, wires, and filters.

HELP???????????

 

Before you do anything else, I would recommend you take a look at this site www.fordfuelinjection.com . The vehicle should be spitting out codes, your mechanic is either trying to rip you off, or doesn't know what he is doing. All you need to check the codes yourself is a paperclip, thats not a joke. The web site I directed you to explains the details of how to retrieve the codes, once you get those, someone on here will help you interperate them. I would also recommend you read through the descriptions of the various sensors that make up the EFI system that they have on there. That will help you understand how it works and to better diagnose the problem(s).


You absolutley cannot just go trying guess what the problem is on an EFI motor, of you do you will waste alot of money and probably never fix it. The ECU is there to tell you what the problem is, so best to use it.

 

It was a transmission shop, I know them well. I thought my tranny was dragging my engine down, I asked them to service the tranny and replace my drippy rear main seal ($350, not bad?). He did the seal and told me the tranny was fine but needed (and got) a good thorough flush.

So I asked him why the hunting and smoke. His code reader gave the aforementioned message (...........60 seconds.....blah blah blah.....). He suggested the air leak in the intake manifold (which doesn't explain the smoke) and suggested a new MAP senser, which I did (OUCH) myself.

So before I make a novel out of this, thanks for the link to the injecter site, I've read a lot there and this place reads like they know their stuff.

I'll try the code reading, but still don't understand why it ran so well BEFORE I changed the plugs and filters, and now it's so crappy???????

Last air-care (1 year ago) was a snap.

Maybe the Bardahl No-Smoke/Stop Leak I put in to appease my GF (she was getting pissed at the drops in the driveway) has plugged or stuck something?

Thanks for your quick reply, gotta go get a paper clip.........

 

double check how you routed the plug wires. make sure 7 & 8 plug wires are not touching at all. also make sure you didnt plug the wrong wire into the wrong plug. what brand spark plugs and what did you gap them to. when you checked the timing what was it set at and did you remove the spout connector? make sure the motor is at full op temp before retrieving codes.

a vacum leak can cause a rich conditon because the computer is trying to compensate for more air. fixing this leak should be a priority before replacing any sensor.

 

Like Kemical burns says, look for the vacuum leaks. I dont remember how the plug wires are routed around the engine bay on a 302, but I would look to see if you broke a vacuum line or knocked a line off a port when running the wires. It is not easy to get to alot of the plugs and there are vacuum lines running all over the engine bay. So it would be easy to hit a line just right with a knuckle, elbow, or forearm trying to loosen spark plugs.

 

If there is alot of black smoke comming out the rear just tell everyone you put a diesel in it.

 

Can't find the spout connecter, 'cause I don't know what it is. The timing is supposed to be 10' BTDC. Thats where it is. 7 & 8 wires are touching, but they are routed together through the harness (I'll change that). I have looked for a break or crack in the vacuum hoses, but can't find anything obvious. I first installed NGK's as recommended at .045. I switched to Bosch (same gap) as I was blaming it on the NGK's....no difference.

The engine runs smooth and well above 1000rpm. below that it hunts. When I rev it (in neutral) or when I boot it (to pass or climb a hill) there is smoke. That is not normal. When its cold, no problem, once it's warmed up, that's when it's crappy. I agree it must be a vacuum problem (timing/ignition issues don't generally create smoke, fuel/air mixtures do). Aside from the vacuum hoses attached to the MAP senser and manifold, how many more should there be?

Thanks for your response, my left leg is getting worn out.

 

Sounds like the IAC (idle air control valve) to me.

 

The spout connector is on the distributor. It is a little grey connector on the front(two wires). all it is is a disconnect. I would say the engine is running rich at idle and when you get on it it spews the build up associated with running rich out the tail pipes. Rich=excessive Carbon, carbon=Black smoke. I would check for a vacuum leak on the intake manifold. Take a can of carb cleaner and spray it on the manifold where it seals to the head and plenum. If the engine idles up you have found your problem. Also if it turns out ot be intake manifold related don't use the cork gasket that goes over the plenum, use RTV instead. Also once you do get it running right I would suggest using a can of seafoam on it and hot soaking it.

 

the smoke could be caused by a out of whack tps (throttle posistion sensor) if it thinks your giving it alot more throttle than you are, it will be overfueling hence the black smoke. just a thought.

 

I've read a lot here about seafoam, some good and some bad. I've never heard of "hot soaking". What would that entail? Rich at idle sounds bang-on, but why would it only start immediately after changing plugs, filters, etc? When I swapped out the NGK's that I thought were the problem, they were all black and carboned up bad. BUT it ran great with no problems prior to the "tune-up".

I appreciate all the insight here, my week-end is now booked solid...............

 

A hot soak is a term we use in The BMW world. Don't know if it comes into the ford world. what you do is bring the vehicle to normal operating temp and once at temp use a vacuum line to suck 1/3 of the pint of seafoam. Once it gets sucked in turn the engine off and let it sit for 15-20 mins, hence the term hot-soak. Once it has sat for 20 or so mins start it up and run it, drive it. It will smoke badly, but once you are finished the engine will run like a whole other engine. Also if the plugs are fouled out that is another sign of too much gasoline, and not a good combustion. Again could be a number of things. TPS is one of them. I would check the TPS for resitence and reset it, or if it falls out of accepted values you've found your problem. Also check the wires at night and see if they are arcing anywhere. I have seen faulty plug wires right out of the box. Since it happened after you installed them.

 

try pulling the codes yourself first. check for vacum leaks as mentioned above.
http://www.supermotors.net/getfile/1...connectors.jpg this link should show what the spout looks like, its the black connector hanging there. this part is important to the ecu working properly.

check fuel pressure at the shrader valve and pull vac line off of Fuel pressure regulator with engine running to see if gas comes out of that vac port. if so then that is also part of your issue. does the motor warm up all the way? when was the Tstat changed last. also those bosch plugs are the cheap copper ones right

 

USE A VACUUM?.... how do I do that? through the valve cover? And after the "smoke badly" period, do I need to change the oil? AND... what is TPS? I have done the "dark" check of the wires, thats how I originally found the broken plug. AND the Bosch plugs are NOT the cheap ones.

thanks a heap

 

Thanks for the link, the name "spout" threw me off, I expected something connected to the fuel line (duhhh?). And no, they are not the cheap plugs.