Well, I've just fitted a new TPS & IAC valve to no avail

I had the battery off so the computer wouldn't still be adapting to the old sensors just in case.

Still chokes out when I shift from Park to Neutral- see black smoke belching out of the tailpipe for a few seconds, then she recovers (sometimes). Apart from that, she idles nicely... better now than she was- doesn't seem to be hunting any more.
When I start her when warm, she seems to try & catch then dies- I have to slowly increase the throttle to start her... unsure what she's like now when cold.

I've cleaned the throttle body & intake manifold, new O2 sensor, plugs, tried another MAP sensor, disconnected the EGR valve.

Obviously I'm missing something & it's driving me mad.

Help! Please!

 

After reading your post and replys I am kind of thinking that you need to check your fuel pressure to see if you have an injector or two sticking open and flooding your cylinders. Attach a pressure gage on your fuel rail and turn on the key and then turn it off, if it drops off immediately, you have a problem there.

 

well well , where do I begin , tried pulling codes today , seems most likely is the egr valve , Question when unplugged should it make a difference in the engine , as it doesn't on mine,had a power sterring sensor code , cleaned up contacts , seemed to have cleared for now , getting a 313 code , thermator air not bypassed ,I really have not idea what that is unless it has to do with egr valve .I also do believe number one injector may be faulty , seemed to get a lot of 1 codes , I am going to start with egr valve an upate on results

 

RE: Knightmayre

Your problem sounds a lot like the one had a few months ago with my "87 302. It turned out to be the fuel presure regulator. I pulled the vacumn hose off of it and gas squirted out.

 

Black874X4 Hey, that is a real good possibility, that is one angle that many don't think to look at.

 

I just ran outside & pulled the vacuum line off the fuel pressure regulator. No gas spurted out, but it didn't seem to make any difference. Vacuum was present.

However I noticed that now, when cold, it started but the Check Engine light came on, and the idle was really really low. About 2 minutes into idle, the light went off & my idle went high again.

I can drive up my road without touching the gas & she'll shift up into 3rd gear about 25 mph. When I initially touch the gas, she bogs out slightly then clears.

Am going to try mantta's idea as soon as I can borrow a pressure guage. Am also going to scope the left bank of injectors to get an idea of the pulse width, but without knowing what it should be it would be fairly meaningless. Pulled the codes again, got 11's (Pass) on KOEO & then 44,21,13... not seen the 44 before (thermactor?).

 

trooper
The thermactor air (smog pump) has nothing to do with the EGR, other than the fact that the systems share the vacuum reservoir on the R wheelwell and are controlled by the 3 vacuum solenoid valves (1 for EGR; 2 for thermactor air).

The EGR sensor is only active at high RPMs, so unplugging it at idle won't affect anything. Same for the EGR vacuum line, unless there's a vacuum leak in the solenoid valve.

Knightmayre
Your FPR vacuum line results are normal.

Did the idle go abnormally high, or just back up to normal (~750) from "really really low"? It sounds like you have IAC problems, or base timing/ignition...

 

Steve:

Abnormally high (35mph on idle?), and IAC is brand new. (see earlier posts in this thread)

Base timing I did by slowly retarding the distributor until it stopped pinking on acceleration- couldn't find timing marks to do it properly. Think it's still too far advanced? That would cause it to flood?

Me baffled!

 

Could be an ECT sensor. If it is bad, or the ECT circuit is open it would tell the computer the coolant temp is -40 and the computer would give the engine a very rich mixture. The sensors are only about $20.

 

I have a 93 F-150.About a year ago the fuel pressure regulator went out.there had been previous drops in oil pressure.i could smell gas in the oil,all you have to do is smell the dipstick. i was told that a bad regulator is the only thing that will cause gas to go in the oil.after replacin it and changin the oil it has been fine ever since

 

The FPR doesn't allow gas into crankcase, but it makes the engine run rich, and THAT causes gasoline to get by the rings into the oil. Anything that makes an engine run rich will do that. Normally, there's a little, but the PCV valve is supposed to remove that small amount.

 

ok,but mine had way more than a little gas in it,ans the FPR was bad,i dont know how it all works,i just somehow ended up with very thin oil .i saw a post somewhere about someones front tank pumop goin out,and them still having a problem,it was the round black thing they said .Do you know the real name for it,cuz i think i need one and i would feel kinda stupid askin at autozone for "The round black thing" lol. hey ,memphis,i was in Southaven for almost a year .

 

...and you escaped?

If you mean the tank select valve inside the L frame rail just ahead of the axle, the technical name is the "dual-function reservoir" on dual-tank systems and "single-function reservoir" on single-tank systems. If you have the latest Haynes (the light blue one), they're on pp.4-14 & 4-15. You might find the same diagrams here.

 

Well, here I am again

Someone else told me that the Air Charge Temperature sensor would be covered in goop, and that would affect the mixture. I pull it out yesterday and et voila, covered in goop! I happily cleaned it all off & the van is still the same.

Couldn't find anyone (even my 3 local garages) with a fuel pressure guage, so I just decided to put a new regulator in there. Rail was still pressurized, so am assuming that I don't have a stuck injector.

Still made no difference. Ended up flooded-out in town, in the middle lane right outside the police station, so I soon had lots of multi-colored strobes flashing all over the place. (and he was nice enough to help me push it to get it rolling down the hill back to work). Is extremely hard to re-start if flooded.

So to repeat, on a cold start the CE illuminates right after start along with a really low idle. As it warms up, the CE light will go out, accompanied by a rise in idle. This only lasts momentarily before the CE light illuminates again & brings the idle really low again. The system seems to "fight" like this for a while, before the CE light goes out & the idle goes high again. When I say high, I mean high enough to now drive at about 40mph on a level road. Also, the van floods out when shifting gear selection. If she doesn't flood out, the idle will skyrocket when shifting gear & take a long time to come down. She also surges when the transmission drops a gear, very noticeable- has spun tires on mud & ice so far doing that, which isn't nice either. Still getting an awful wallet-shredding 6mpg.

Running Codes are still 12,21,44,13. Can't find out what 44 is, & KOEO is still giving me 2 passes.

New FPR, TPS, IAC, O2 sensor & plugs. MAP sensor been swopped with 2 other known good units. TB, inlet manifold & ACT sensor cleaned.

Any other ideas?

 

A code 44 is thermactor air system inoperative on the right side.