I am kinda lost at where to start here , I hope someone out there has some suggestions as to where to start . ok first the problem truck starts on a touch of the key , works well until it warms up , then will stall at a stop sign or light ,unless put in neutral and get the revs up , one other symtom that goes along with it is the oil pressure gauge drops right down , after a stall very hard to start and may flood easily and just completely soak plugs , there is new plugs (gapped at 0.44) new wires , new cap and rotar button computer was replaced about 2 years ago. checked over for vacumm leaks , couldn't find any . So here is the question a) could it be a cooling sensor? b) magnetic pick up in distributor? c) coil d) problems with the tranny that when it warms up it drags the engine down due to drag from dirty valves it is a aod I believe 1, drive, and overdrive. Any idea where the best place to start is or is it just a start replacing parts and hope to find it . in addition if truck is let to run it will idle fine , alittle loopy after warming up but oil pressure stays up ANy help on this would be greatly appreciated Thanks :-)

 

Pull the codes.

 

Sounds like your engine is just running too rich. The codes should point you to the culprit. Could be o2 sensor, dirty or defective injectors, or bad pressure regulator.

 

thanks guys , I should have menioned it was already on diagnostics , and no codes came up , said all was fine, that is the cofusing part , which leads me to believe cooling sensor , magnetic pick up , or coil , or god no the tranny , thanks for the ideas though , all ideas are a big help right now

 

The computer monitors everything you mentioned, so it can usually detect significant problems with them, but it's not very intricate and is dependent on the sensors that it's diagnosing. Get a Haynes manual and test each sensor with a multimeter.

 

Hello,
Did you check your TFI module? On the 87s the TFI module is still on the Distributor if I remember correctly. They tend to not like heat. That is why on the later years, the TFI module is on the firewall in a heat sink. Bet that the TFI module works fine when it is cold, then when it gets hot, then it acts up.

Hope this helps,

Tim in Detroit

 

Check you're coolant temp sensor if it's not there it will run like crap after the engine's warm

 

Thanks everyone for your great tips , just went through my haynes book again , absolutly noting about how to get the codes or what the codes are. just to clrify it is an 1987 f150 4x4 5.0L or 302 fuel injected, this truck doesn't have a check engine light or even the socket for it ,so is it done by one of the other gauges? I twas like I said put on a cumputer at a guys shop and apparently didn't show anything, but would like to try and code it myself anyone know some links that might help on this model?

 

The link that Steve83 put up above here will show you how to pull the codes. Just click on the blue "Pull the Codes." You'll have to use a multimeter to pull the codes, because you're right, it does not have a check engine light, only an emissions light. I've got an 87 302 also.

 

I have same year and engine but 2 WD. At about 100k, similar symtoms but I don't recall flooding (how on an EFI?) or oil pressure drop. At the time, I didn't work on it much, so to the shop. They replaced the idle air bypass and it was fine.

 

hi there , well steve as I have found out , this engine fires four cyclinders at a time on the injectors ,how it floods , I am guessing it is figuring it is an all go on start up and just not getting the fire to get rid of the fuel ,have taken plugs out and literally soaked and i mean soaked , near gas dripping off of them , very surprised seeing it myself.on one occasion just prior to computer replacement it locked open 4 injectors, talk about a nasty situation there , but finally found out the hard way now as long as I don't ry to hard when it stalls and hot , it starts right up , just waiting to pull the codes myself , thanks to the guys above , just very cold weather here today or would have been at it -31 windchill , alittle cold to be playing to much

 

Good luck Trooper31 and let us know what codes you come up with if it ever warms up. -31, I don't think I'd play too much in that either!

 

I have an 88 E150 (302 EFI) with the same problems, except the oil pressure dip. Mine does it when I shift into gear (any gear)... seems to go to full rich - black smoke from exhaust before it stalls. Floods so badly that it can flatten the battery before I can catch it just right- have to hold the throttle to the floor to turn the injectors off while cranking, which results in spectacular clouds of smoke before it catch & run. Then I have to wait for ages before I can put it in gear or she'll do it again. Unfortuantly this is an intermittent type fault- if she's idling a little high I have no problems. When she's misbehaving, I can't even shift from Park to Neutral without it flooding out on me, even if I do hold the idle way up (which I abhor doing). The other night I was left blocking a little 2 lane road after backing out a drive, then shifting to go. Took 8 scary minutes before I could get her running again, and another 20 before she'd deign to go into gear without flooding.

I'm also getting horrendous gas mileage - 6mpg

I took the IAC & TPS off & threw them in an ultrasonic cleaner & found the intake manifold covered in about 1/8" of black crud (same on the rear of the throttle butterflies). IAC was black & cruddy, but cleaned up beautifully.

I need to reset my base timing as I timed it by ear, and retarded it a little when I was cleaning it up. I'm going to put in a new TPS this weekend & re-time her. I've been told that 302s run cold, but mine runs really cold, (can't change thermostat as the right-hand crew is a PITA to get at, and the left hand one was breaking my torque wrench which was set at 150 foot/lbs) and I was thinking that the computer might be richening up my mixture as it thinks the motor is cold, but surely not enough to flood it out or give me only 6mpg.

Has new plugs & O2 sensor. I've pulled all the connectors on the engine & checked them for cleanliness & corrosion- none evident.

The only codes I get is a 21 on a KEOR & 11's on KOEO.

Haynes manual has no information in it for my model, so I'm working off my Taurus & Ranger manuals for sensor info etc, which is a pain.

If you get your truck running nicely again, please holler at me & let you know what you found & I'll repost Sunday after I play around some more.

 

wow sure hit it on the head there , unfortunatly still very cold today so I didn't get the chance to pull codes , but I had to take the beast down to the store basically 3 blocks away,worked great on ethe way down and back , tried to back into driveway , got half way back across street and dies ,no warning , bugger to restart (as everyone knows a f150 4x4 with decent muds on takes up a far bit of road ) finally restarts and pulled in no prob , seemed like lots of snort , starting to think now might be the power steering sensor that is a part of the problem , not all but wheels were cut just before it died ,and sounded like the typical flood out it does , but managed to catch it , and lets just say it didn't have a chance to stall again :-) so my best guess at this point is ...I suspect power steering pressure sensor ,but not limited to that , I also suspect cooling sensor . local people keep telling me the magnetic pick up , possible but I find hard to believe when it fires up with half a key turn ,just right there , and sounds so strong , I will know better when I pull the codes myself thanks to the great guys on here, and will certainly pass on the results and hopefully help someone else out down the road on this long nerve racking expierience. all you guys are great and appreciate all your wisdom on this mind boggling situation as I am from a small town , in a small province on the east side of canada ,not too many shops a fella can run to for help . again you guys are GREAT !!!

 

Your oil pressure is dropping from the gasoline thinning it out. That's how I killed my old carb engine in 30Kmi. Bear in mind that the injectors get power whenever the key is on, so a short to ground on the NON-red wire (tan for one bank & gray for the other, I think) will hold them open. Check for chafing on the harness.