1991 F150XLT, 5.0, E4OD....Should the EFI system bump up the idle speed when the AC system is operating to compensate for the compressor load? Obviously I'm asking because mine sure doesn't. With AC on, the idle speed will drop to around 300rpm in Drive, like when sitting at a red light for example. Surely this isn't normal operation...is it?
View 4 RepliesI just bought a 1991 F150 with a 302 (5.0). It idles at around 2600-2800 RPMs. The previous owners replaced the TPS and IAC, but it still idles fast. Ford dealership told them it was a vacuum leak. Are all the vacuum lines close to each other? How easy is it to locate/fix the problem?
View 2 RepliesI picked up a 90 f150 with the 302. it wont idle without a little throttle, so after a quick look under the hood i noticed alot of broken torn and missing vacuum lines. Where I can get some sort of diagram for routing?
View 1 RepliesI have a 1984 Ford F-150 with an I6 engine and a motorcraft carburetor. The truck absolutely will not idle. So I got to looking at the carburetor, and found this red hose going from the carb to a metal pipe, the pipe was just dangling there not connected to anything, and the end it rusted off. I'm pretty sure I know where the other end is supposed to go to, I just don't know how to get there as obviously I am missing some parts and I can't find them so they must have been lost on the road somewhere.
Here's how it looks:
The end of the pipe:
Where it is supposed to end (I think)???
I have an ambient temp switch connected to the vac port on my throttle emissions control solenoid for my 2150 carburetor. It's a 78 F-150 with a 5.0L 302, automatic 2WD. Would a bad ambient temp switch screw up my idle? I've disconnected the vac hose and it won't idle at all, and it does the same thing when I disconnect the two wires from the ambient temp switch. If I leave everything alone, I can get the idle down to around 1800rpm, but any lower than that and it stalls.
Is it possible to swap out this throttle emissions control solenoid with another type? I've looked everywhere and can't find an exact replacement, and I have no instructions on how to tune it.
I just bought another 1991 Ford. This one is a 1/2 ton XLT Lariet with the 302 and for the first time I own a short bed. I also have a 1991 F-250 XLT with a 460 and a 8' bed.
Here is the problem, ( I think) it will not run or at least not for long. The fuel pump, which I am guessing is in the rear tank will not stop running. On the F-250 the pump stops running after a few seconds after I turn on the key.
Where should I start to find out my problem with the fuel system?
My vehicle:
1976 F150 2wd Extended cab
390 4bbl
c6 transmission
4BBL Edlebrock Carb
Dual fuel tanks, only rear main tank connected
My problem: For the first year I owned the truck, everything ran fine and it started up really quickly even after it sat for a few days or a few weeks. I have since, for about the last year or so, had to crank it for 30-45 seconds to get it to start. This all started around the time my fuel pump went out. I replaced it with an Airtex fuel pump from Autozone. I also installed a glass in line filter before the carb in front of the distributor.
I noticed that after about 4-6 hours, the fuel had drained out of the filter and that's when I would have to crank it forever to get it going. It also seems like there is no fuel in the carb as it doesn't even try to start when it first gets cranked. I thought this was a bad pump, so I bought a new one last week and tried it again. Sure enough after about 4-6 hours, everything is empty again and it takes forever to start it. So it's not a bad pump, or so I think.
The other day I backed it into my driveway and left it, something I never do. I checked about 4 days later and there was still fuel in the filter. This makes me think that gravity is making it drain back to the tank.
Is there something that would cause this? Also I have found a one way fuel check valve online that is supposed to remedy this type of problem. Do they work for this situation? Or is there something else I should be doing to fix this? It has taken a bit of a toll on my starting system having to crank so long all the time. I have so far had to replace my starter, starter solenoid, and all the battery cables, starter cable, terminals, etc. due to excessive wear.
The valve I found is here : [URL] .....
I've got a 01 f150 yesterday stopped running (like it ran out of gas). Has half a tank. Fuel pressure at rails good but truck will not turn over. Fuel pump and filter less than year old.
View 1 RepliesI've had a fuel leak near the pump of my 79 F150 with a 400 for some time. I didn't know exactly where it was coiming from, but fuel was being sprayed on to the oil filter from something near the pump. I assumed it was the steel line, and that it had rusted through or cracked, and was going to replace it when I had a chance. I was poking around today though, and realized that the fuel was not leaking from the line, but from a hole in the side of the mechanical pump.
For someone who knows what these pumps look like, there is a horizontal cylindrical bump out near the top of the pump, on the side of the pump that is away from the engine. The fuel is spraying in a mist out of one side of that. To me, it always seemed to be a screw channel, but I didn't think the pump was 2 halves put together? Need to know more about my pump, what that bumped out section is, or why/how fuel could be spraying out of it.
1993 F150 302. What does the fuel canister purge solenoid/vac play in the furl/emissions arena?
View 5 Repliescant figur this out have no signal to injectors and no power at fuel pump 88 f150 5-0
View 2 RepliesWhy the frame mounted fuel pump might run after the key is turned off? Then when you turn the key on it may or not run. If it does run it keeps running. shouldn't this shut off after pressurizing the line? is their a pressure switch in the pump that's failing? This has the 3 pump system...
View 4 Repliesfor the past week we have been trying to figure out what is wrong with our truck. We recently bought it and it ran fine. Then got in a minor accident just a fender bender and it started acting up so I got towed to garage. First it would run when cold, but when hot fuel pressure would drop to 28 psi.
So I put new fuel pump, it started but still did the same thing hot 28 psi fuel pressure shuts off. So I put regulator on it, then had 0 fuel pressure won't even start. So got a another regulator thinking I got a bad one, still 0. Checked relay, there fine. I'm gonna check lines and see where fuel stops at but everything is new on it.
I have an 87 F150 4x4 4.9L EFI with a single tank. Fuel pumps keep running even when the key is off. I tried swapping relays but the problem still exists. The engine will start and run OK for about 15 secs. then die. I installed a new low pressure pump, high pressure pump seems to be OK. I also installed new fuel filters. I dont want to just throw parts at this truck, where do I go from here?
View 4 Replies1994 150 300 6. parked truck after lunch finished work and it wont start no fuel comes out of the valve. Can't get the pump to work even when jumping the 6 pin. heard the relay click still nothing. Checked the inertia switch it wasn't popped. Took the pump out jumped it straight from the battery pump works . I know there has to be something i am missing...
View 7 RepliesI'm looking at replacing the fuel lines in my 94 F150 and the big question is what to do with hooking up to the fuel lines coming out of the fuel pump hat and the fuel rails? Ford uses a specialized pressure fitting on it's custom fuel lines. I think there may be some third party fittings that would replace these, but I'm not sure. I could use a standard hose and cable clamps, but I just don't trust that kind of connection for a fuel line.
View 5 RepliesI have a 1986 F150 6 cyl, dual tanks, no AC, manual fuel pump. Just recently, I have been having issues with the tanks. At first it seemed like the back tank was siphoning from the front tank. Now I have fuel coming out of my front tank filler neck. When I open the back tank gas cap, there is enough pressure to spray me with gasoline. I am not familiar with the fuel delivery system of my truck ...
View 2 RepliesMy 88 F150 (300 six, 5 speed, dual tanks, 176,000 miles). The truck has the low pressure fuel pumps in the tanks and the high pressure pump on the frame rail setup. Truck starts fine, but cuts out severely under acceleration for the first 30 seconds of driving. After that I only notice the problem when applying a lot of throttle (does not cut out under gradual acceleration) or climbing steeper hills. If I kill it for a few minutes and then take off again the problem is back for the first 30 seconds or so. I have replaced all the tune-up type stuff (all filters, plugs & wires, dist. cap & rotor, ignition coil, o2 sensor, cleaned throttle body, replaced IAC valve, numerous sensors). Timing is dead on at 10 deg. BTDC with SPOUT unplugged. My FPR was bad so I also replaced that. Condition exists regardless of which fuel tank I am using (no problems with tank selector).
Getting no KOEO codes, but getting KOER code 41 and plugs do seem to show a lean condition possibly. I'm still averaging around 16 MPG since this became a real problem about 3 months ago.
I removed the bowl from the reservoir between the tanks and the high pressure pump on the frame. No filter in there, but it was clean with no gunk or sediment found. I removed the line from the inlet side of the high pressure pump and found that while cranking the engine I have fuel flowing freely (same amount of flow regardless of which tank I've switched to). The flow was steady, but not extremely strong. If I understand right the in-tank pumps are not designed to provide much pressure? Below is what I found at the schrader valve:
key on, engine off - high pressure pumps runs for about 1 second, brings gauge up to 48 psi
idle, FPR connected - 40 psi
idle FPR disconnected - 52 psi
revving throttle with FPR connected - 46 psi maximum
Connector, where fuel pump relay plugs in, seems to be clean and not corroded at all.
I have an 87 f150 inline 6 efi. The truck will not rev over 2000 rpm even when idling. It has a new fuel filter. What this could be?
View 2 RepliesWhat to do next. Engine is running on 4 cylinders, #1, 4, 5, 8. Had a mice nest on top of injector #2. Removed mice nest. The mice had chewed through wire for #2 injector and caused bear lead rubbing on the block. One lead rubbed through. Repaired, splised in a wire. Also changed rotor, rotor cap, all sparkplug leads and plugs.
Troubleshooting.
Compression on all 8 cylinders measured to be above 160 psi.
There is spark to all 8 cylinders, including the other 4 cylinders, 2, 3, 6, 7 that is nor developing power.
Fuel rail pressure is 35 psi on idle and spikes to 43 when reving the engine.
The fuel injector resistance all all measured injectors are the same (about 14.8 Ohm). Measured injector # 1, 2, 5, 6, 7, 8. Injector # 3 and 4 is hidden and require too much disassembly. Visual inspection deems wire for #3 and 4 injector to be ok on top of block.
Electric impulse (tested while engine was running) to injector # 1, 5 and 8 are ok, used test lamp to see that there are electric impulse to the injectors. Injector #2, 6 and 7 does not have any electric impulse. Unable to check electric impulse to # 3 and 4. However cylinder #4 develops power. Used moving the sparkplug wire for cylinder #4 to verify that is is developing power.
What would my next step be? Where should i look next?
1. Where is the control module and is it likely to fire to only 4 cylinders
2. Could it be an wire in the pickup element, under the distributor. All wires seem intact.
I have a 1994 f 150 5.8l 4x4 with 215000. Cold starting is fine runs well. After running it will not start after shut down. Wait till motor cools back down will start up and run fine ....
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