Fuel pump not priming

jdsgallops

Registered User
Ok vacation has started so it time to get the SC running and put of the garage. For those that have forgotten or nog followed my other threads . I will review.

About a year and a half ago the car just died trying to merge onto the interstate. It was towed home. When I finally had time to look at it all indicators were crank sensor. It was replaced. Still no go found so ble in the balancer so it was replaced. Still wobbled. Upon engine removal the crank was found to be broken. The engine was rebuilt and reinstalled. It would not fire. Upon David N's suggestion I reinstalled the cam sensor correctly. It was also pointed out to make sure I had the ground for the computer near the battery connected. Before I reinstalled the cam sensor I could get the car to back fire starting it with cam sensor unplugged. I have gotten nothing since reinstall.

The general consensus has been a bad ground. So this morning I ran a jumper cable from the starter to the negative side of the battery. Same slow turn over. My next step was to chec k for power at the computer. This is when I noticed the fuel pump not priming Not a peep. Brake booster did prime.

I have a new ignition switch on the way. The door locks still buzz when trying to start. Starter was replaced along with a 1/0 solenoid to starter cable. With all of the things going on does it sound like a computer issue? The fuel pump looks to be original but worked fine before the car died. It is on the replacement list once it is running. I am terrible at wiring so I am unsure where to go from here. Anybinput is appreciated!
 
could be the pump relay, not the pump, need to check that you are getting power to the pump. Another quick thing to try is to have someone else cycle the key on/off a few times while you are under the car and take a rubber mallet and bang the bottom of the tank while they are doing it. That will sometimes "free up" a pump that has been sitting awhile.

Adam
 
IMHO:
You should try to keep the diagnosis in one thread. You don't even mention what year it is in this one.
I went back to your crank/cam thread and doing this is like starting over again from scratch, unless that's what you want :confused: That just seems like more work.

If from sitting overnight you go out and turn the key to "ON" and can't hear the fuel pump that is a problem.

If the engine is cranking slow, that is a problem as the starter might be sucking in so much electricity you don't have enough for the electronics to prime and or fire the engine.

The aftermarket alarm system, another possible problem.

The locks buzzing while you're trying to start and the seat belts not functioning properly another problem or two.

You need to pull the fuse(s) to those systems until you figure out the starting issue or fix the problems and then start on the engines problems.
Maybe you should pull everything that isn't necessary for the fuel, ignition and cranking and see what happens to the starters cranking speed ??
Have you had the battery tested yet to make sure it's good. Not that you think it is but tested with a load and know it's good ??

You should also make sure "we" know if the problem was there before the engine broke and was repaired or if the problem is something new since the rebuild and install. If it's something new it's likely related to the starting issue.
 
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I had a somewhat similar problem my sc died and I tried a million different things and I finally figured out that the IRCM (the computer by the air filter for my 89) was pulling a ground from my injectors and that screwed a whole bunch of crap up including fuel pump priming and showed the signs of a bad ICM and crank sensors but I've since got it working fine with all the old parts. What I did was I acquired a wiring diagram packet that showed what all the wires in the car did and there colors and so on. So I solved the problem by running a constant ground into the IRCM ground wire from the frame. I just soldered it in a T shape all sloppy like and after I reconnected the batter it fired right up. I can't believe it worked but it did.
 
Deff start with the relay I've two go bad due to water coming in from bad trunk seals even if its been in a garage water could have been in it this whole time mine was in storage for a year pulled it out and found water in the relay
 
IMHO:
You should try to keep the diagnosis in one thread. You don't even mention what year it is in this one.
I went back to your crank/cam thread and doing this is like starting over again from scratch, unless that's what you want :confused: That just seems like more work.

I don't see how reviving a thread a couple of months old and goes in several different directions helps me get an answer. All it means is any one interested in helping me needs to read the entire thread to know what has been done. If it was kept fresh every day I may agree with you.


If from sitting overnight you go out and turn the key to "ON" and can't hear the fuel pump that is a problem.

It didn't happen overnight. Before I reinstalled the cam sensor and added the ground at the radiator core support from the battery the car would pop through the exhaust with the cam sensor unplugged. I could also smell fuel when trying to start it. It has not popped through the exhaust since then with cam sensor plugged or unplugged. Therefore something that has been done along the way has affected it. My gut is telling me the computer became a ground and has been blown.

If the engine is cranking slow, that is a problem as the starter might be sucking in so much electricity you don't have enough for the electronics to prime and or fire the engine.

The aftermarket alarm system, another possible problem.

The locks buzzing while you're trying to start and the seat belts not functioning properly another problem or two.

You need to pull the fuse(s) to those systems until you figure out the starting issue or fix the problems and then start on the engines problems.
Maybe you should pull everything that isn't necessary for the fuel, ignition and cranking and see what happens to the starters cranking speed ??
Have you had the battery tested yet to make sure it's good. Not that you think it is but tested with a load and know it's good ??

Except all these issues are electrical issues and all of the showed up after engine reinstall. The car was a daily driver until it quit coming home from work one day. The only major flaw was a vibration that I still hadn't found. It had gone from being almost undriveable to what I felt was as good as it was going to get from the age of the car and inherent nature of the v6. After finding the broken crank I am hoping it was the cause of said vibration I could not find. The battery has tested bad. Moot point though as when using the battery out of my daily driver it presents the same problems. I see no need to buy a battery for testing purposes until the car is running. All it will do is shorten the life of the battery. Using the 50amp booster setting on the battery charger also results in the same symptoms.

You should also make sure "we" know if the problem was there before the engine broke and was repaired or if the problem is something new since the rebuild and install. If it's something new it's likely related to the starting issue.

It is a 1990 SC. I will double check but I am pretty sure the inertia switch was reset.
 
To show just how preoccupied I am these days I have found the problem. Seems on one of my last diagnoising outings I was playing with the computer trying to get it out. With the time between openings for me to work on this thing I had forgotten that is where I had left off. In doing so I had left 2 connectors by the computer unplugged. Plug them in and the cam sensor and hit the key. She came to life and for the min or two it ran worked perfectly. Unfortunately my time was cut short by a leak coming from the coolant hose under the air intake. Looks to be coming from the cap I put on when deleting the coolant hose coming from the throttle body. At least that is an easy fix!
 
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