Trans Sport :: 1996 3.4L Van - No Start Intermittently / Fuel Pump Relay Chattering
I have a 1996 Pontiac Trans Sport 3.4L (without Passkey anti-theft) which on occasion won't start after being parked. The fault only happens when the vehicle has been sitting, it does not die while being driven (so far). The engine cranks normally but does not fire. The peculiar and significant thing about the fault is that the fuel pump relay (driven directly by the PCM), chatters at about a 10 Hz rate. Instead of receiving a steady 12VDC to keep it energized, it is receiving a pulse stream from the PCM.
The first few times this occurred, I heard the relay "chattering " under the hood , and was able to start the van by unplugging the relay and shorting the connector terminals for the contacts together with a wire jumper ( these terminals connect "hot at all times" 12VDC from the PCM fuse (orange wire) through the relay contacts to the fuel pump +ve). The electric pump would run and I could start the engine easily. By the time I arrived at my destination, the fuel pump relay 'drive' would be normal and I could plug the relay back in and continue normal operation.
The last few times this problem occurred, the van would not fire -- no spark as long as the relay drive was pulsing. When it would finally go back to normal operation of the relay, the engine would start OK.
Last Spring in cold weather I had the van towed 2 blocks to a Pontiac dealer with this problem. The problem resolved before they inspected it; however after the Technician's inspection the Service Advisor said there was no fuel pressure at the test port and that the pump must be deffective (shorted), overloading the relay causing it to chatter. That diagnosis made no sense to me. They wanted to replace the fuel pump as the solution ($600). I got past the Service Advisor and asked the mechanic to show me the fuel pressure -- the car started on the hoist when I tried it, and fuel pressure was normal (>30psi). I left with just the relay changed, as they thought the original would have burned -up contacts from excessive current to the pump. (I cut it open later and found its' contacts to be perfect). While at the dealership I asked the S.A. if he knew of any TSBs, or other incidences of this problem; he said he had not heard of this problem before.
I had the same problem one week later, but not again all summer until this Fall's cold and wet weather. I had to have the vehicle towed home and it still wouldn't start the next day. As soon as I accessed the PCM behind the glove box and jiggled it the relay chattering stopped and car could start. However, later the same day, still in the driveway, the fault was back and no amount of jiggling or other manipulations had any effect. Later still I went out to test for spark, and the fault was gone. (Cold, wet weather all day).
Vibration seems to have little effect. I have checked the PCM connectors' security and pulled, twisted and wiggled the wires coming from it, as mentioned above, to no effect. I suspect the fault is inside the PCM and is thermally induced by cold weather. The next time it happens I will try a warm hair dryer on the aluminum housing of the PCM. I wonder if there is a fix for this (repair a cracked solder joint, etc.) other than replacing the PCM. I work in electronics, and will open the PCM up and inspect it before forking out for a new one.
Dodge - Gasoline - Pump - Relay - Dart :: 1971 - Fuel Pump Not Working?
ok, i just became the proud owner of a 71 dodge dart.. fuel pump was not working, and am converting to an electric (airtex e8016s) and am told i need a relay. airtex doesn't seem to have one, is there another i can use? fairly new at this sort of thing, but have fixed a 72 honda motorbike, so not afraid of engines or whatnot.
View 19 RepliesFord Fuel System :: F250 Not Getting Voltage To Fuel Pump Relay
My F250 heavy duty isnt getting voltage to the fuel pump relay.....
View 2 RepliesFord 6.7L Power Stroke Diesel :: Aux Fuel Gauge And Fuel Pump Both Quit
I have my aux fuel tank pump hooked to upfitter 3. It has worked perfectly until this week. I started to transfer fuel and the aux fuel gauge and fuel pump both quit. The led on upfitter switch 3 still illuminates, but no fuel pump. I found fuse 9 on passengers kick panel is for upfitter 3. The fuse was good. Is there another fuse somewhere for the circuit I've missed? I can trouble shoot the wiring if necessary, but it's tough to do all behind the left side underbed box and not easy to get to. I've missed something simple before I go further????
View 14 RepliesPrius (Gen 2) :: Loss Of Fuel Economy After Electric Water Pump Replacement
After my electric water pump was replaced under the recall my mileage went from 45 mpg to about 30 mpg. Part of this might be due to new tires and cold snowy weather (CT !) but I have never seen such a drastic drop in performance (2005 Prius).
View 12 RepliesAurora :: 95 - Lost All Power To The Fuel Pump And At Relay
My 95 aurora 4.0 lost all power to the fuel pump and at relay. what could be my problem. Is there a fuel shut off ?
View 2 RepliesLumina :: 95 - Fuel Pump Relay Clicks Without Key In Ignition
Without key even in ignition, fuel pump relay clicks constantly every 8 seconds with the gauge lights illuminating during this 8 seconds. The only lights that function are the gauge lights. Upon turning on the headlight switch only the gauge lights illumin8. Absolutely no headlights, dome light or brake lights. No fuel pump sense/pulse. No radio, key on or in accessories.
Multi-function switch was not the issue. How would I troubleshoot this one?
Chevrolet - S-10 :: 1997 - Fuel Pump Relay Location
I am looking for the location of the fuel pump relay on a 1997 Chevy S10. There is a bank of relays on the firewall on the passenger side, but I do not have any info on which relay is for the fuel pump.
I briefly looked at this vehicle where they had it towed to after it had stalled on the road and they couldn't get it to start.I had no tools at the time, but not hearing the hum of the pump, and no fuel at the test port on the rail, all pointed to a fuel problem. The owners boyfriend took over from there and replaced the pump this past Saturday and still no pump.
I suggested that he find the right relay and test it, but he skipped that part. Which of those realy are for the pump??????
Ford 7.3L Power Stroke (1999-2003) :: Electric Fuel Pump Conversion
I was wondering if it is possible, due to budget, to perform the electric fuel pump conversion in steps. By that I mean could I remove the mechanical pump and install the electric pump on the frame, but retain the stock filter housing and regulator? I would use high pressure hose and run from the stock pump supply line on top of the engine to the fuel bowl inlet and then use high pressure to run to a three way fitting, and a bit more hose to join the fitting to the stock lines running to the head. later as budget allow I will replace the filter assembly and regulator and then the lines to the heads.
View 2 RepliesFord Wiring/Electrical :: 1967 - Installation Of External Electric Fuel Pump?
I have a fuel pump I want to install I want to hook this thing up on a switch inside the cabin to be used as kind of a security device, but I am hoping I can wire it into the ignition as well.... I want the pump to activate when the ignition is turned on but only if the (hidden from view) switch is in the "on" position. Not sure if all this is possible.
I have heard I ought to utilize a relay to avoid voltage loss at the pump. I have never hooked up a relay to anything before although I have heard of them being used. This system is being installed on a 1967 F250.
Ford Fuel System :: 1987 F250 - Swapping Out Mechanical Pump For Electric?
I just purchased an 87 f250 w/ a carb'd 460. I purchased it with the mech fuel pump swapped out to an electric. The previous owner states that they gave him the wrong electric pump and I should exchange it for a different one. The reason for him putting it on was to get it running for me to hear it run.
My question: Is this even recommended? I wouldn't mind staying with an electric pump up front. If it is recommended, what would be a suitable pump to replace it with, as in flow/feeding characteristics?
Also, it only feeds from the rear tank, which also has a bad fuel pump. I'd like to get both tanks functioning again. I'd rather not deal with the tank switching valve due to what I've read about them. Has anyone ever hooked up a manual valve and just switched tanks that way? I've searched this site extensively and couldn't find anything. I know I'm not the first to have thought about it.
Volvo - 940 :: Fuel Pump Replaced Now Fuel Gauge Not Working Right?
Fuel pump in my Volvo 940 has been replaced twice. Since then, my fuel gauge has not worked right and I have had to pump gas about every 120 miles so that the fuel pump would work right. I would fill the tank, and 120 miles (about 5 gallons) later the fuel gauge would indicate about 1/4 tank of gas left. That's when the fuel pump begins to mis-behave. If I make a sharp turn, it would stopped pumping for about 2-3 seconds. If I continue to drive at that level of gas. I can avoid all these problems by keeping the tank at least "half-full", that is, by pumping every 120 miles. The car was totaled by a hail storm and I bought it back for $84. I like to operate the vehicle for as long as I can, one day at a time.
View 1 RepliesBonneville :: 1993 SE - Fuel Pump Is Not Working - Check Relay?
My 1993 Bonneville SE; fuel pump is not working. I don't know if it's the relay or not. How can I check and where is the relay. I have relays in horizontal line in center of my firewall. I am disabled and don't have any other transport.
View 1 RepliesGMC - Jimmy :: 1994 - Died While Driving / Fuel Pump Relay?
My jimmy died on me yesterday on my way home from work...i thought the fuel pump went because i couldn't hear it when trying to restart... I had about a quarter tank of regular in there,,,put in 2 gallons of super and it started, but died again about a quarter mile down the road...got it home with a push...after searching for and checking any fuses i could find...swapped relays on firewall and all seemed well....i heard the pump and it fired right up...went walked, just in case) and got another relay, and now i don't hear the pump again,the battery is a bit low now,,,so maybe a jump would give me enough juice? I'm going to jumper the wires/relay...and be sure the pump is working... I'm sure it is.. 94 jimmy 4.3 vortec 140k I gotta pick up my wife from work later and don't want to get stuck again...
View 9 RepliesFord - Ranger :: 1994 - Loose Fuel Pump Relay
A cousin has an old 1994 Ranger. The fuel pump relay, located in the engine compartment fuse box. went bad, so he got a new relay.
Now, it does not plug in securely, so sometimes he has to open the hood and fuse box and wiggle it to make contact.
Ideally, one would probably replace the fuse box, though that would apparently involve a lot of wiring, right?
How to "cob" this up so the contacts will make better? Perhaps something to put in the slots to increase pressure on the blades?
Maybe gently twist the blades so they go in at an angle? Maybe touch the blades with a solder iron and put on a small blob of solder to make the blade bigger? (Though it seems to me that solder is not a good contact material?
Maybe solder to the blades, a very small piece of brass or similar material? Put a piece of aluminum foil over the blades?
Buick - Century :: 1994 - Relay Not Powering The Fuel Pump
1994 Buick Century 3.1
Fuel pump relay is not powering the fuel pump. I was able at one point to jump the orange wire to the gray wire but it will not even do that now. I know the fuel pump works because I can jump from the battery to the gray wire and it will turn on.
I used a multimeter and tested the volts from the orange wire on the relay to the neg post on the battery and it is only reading about 1.3 volts. Is this normal?
Checked the fuel pump 15a fuse and it is ok. I am getting spark. Could it be the crank sensor? How can I test that? (It is above the start I believe). Could it be the ignition control module? How to test? Location? What else can I test with the multimeter and post back with the results to further diagnose?
Chevrolet - 1500 :: 2008 - Fuel Pump Runs Without Relay?
My plan to clean the fuel injectors on my 2008 Silverado LS 4.8L V8 came to an abrupt halt when I was unable to disable the fuel pump relay because it is missing from the spot where it should be located according to the schematic in the owner's manual. Would removing the "fuel system control module" (fuse #21) instead of the fuel pump relay work?
View 7 RepliesFord Ranger / B-Series :: Intermittent Fuel Pump Relay?
My '94 4.0L XLT has hesitated to start a couple times lately. Then, after sitting for a week while we were on vacation, the truck would not start at all today.
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I read about the fuel pump relay, so since I am not made of money, I decided to change that first ($16 vs. $100). After installing the new relay, the truck started! I put the old relay in the box and tossed it into the glove box.
After lunch, and some thought, i decided I wanted to put the old relay back in and see what happened. Guess what! It started with the old relay as well! I also noticed that the humming/buzzing sound the fuel pump makes when the switch is turned on was different with the new relay vs the old one. I put the new relay back in, but now I am unsure where my real problem lies. Intermittent relay, or fuel pump on its way out??
Corolla / Matrix 2009-13 :: 2010 LE - Cannot Find Fuel Pump Relay
Where the fuel pump relay is in Corolla 2010 le?
View 8 Replies