Defender Source Forum banner

1 - 17 of 17 Posts

·
Premium Member
1994 D90 ST
Joined
·
866 Posts
Discussion Starter · #1 ·
New fuel pump, new injectors, pressure regulator holds a vacuum. What else could be bleeding off fuel pressure while it sits?
 

·
Premium Member
Joined
·
1,490 Posts
I guess I can. Not sure how though.
use a set of hose pinch pliers on the rubber return line right after the regulator, connect pressure tester, build pressure on fuel line by priming fuel pump. monitor static pressure. this will help diagnose if fuel pressure regulator leaks or fuel rail leaks including new injectors.
if all pressures remain steady, inspect steel return line for leaks (even wetness over rust is a leak repair as needed).

if all is well so far, suspect defective new fuel pump check valve.

PS do not use needle nose vise grips, they always allow leak. use proper hose pinchers.
 

·
Premium Member
Joined
·
1,490 Posts
I get this same problem on my 1977 2.25 with a weber 34ICH.
There is no return line on these, any ideas?
totally different animals and set up, a 77 2.25 carbureted versus a 94 fuel injected V8. too many variables on your vehicle to offer a simple solution. Campbel has been chasing this issue for a while on the forum.

defective fuel pump, dirty fuel filter, improper fuel bowl level, improper timing, worn out or improperly gapped ignition points , fouled spark plugs, dirty cap and rotor, worn out/low compression engine. are some concerns which need to be researched in order to make your engine a well tuned machine.
even then a cold carbureted engine needs choke and priming on a first start, fuel injection uses high pressure electric fuel pump and pressure regulator to build and maintain proper constant fuel pressure. ECU's to control injector pulse air meter throtle position etc. again very different animals.
 
  • Like
Reactions: [email protected]

·
Premium Member
1994 D90 ST
Joined
·
866 Posts
Discussion Starter · #9 ·
Reviving this. Still having hard to start problems but it isnt fuel pressure.

I did notice that the ground wire to the battery gets hot when cranking. So I am guessing poor ground causing resistance in the wire.

My question is how would that affect starting? My starter still sounds fine and cranks away. Does a poor battery ground cause issues with getting enough sparks to kick off the engine?
 

·
Premium Member
Joined
·
1,490 Posts
poor connection demands high amperage, this in turn draws voltage from other accessories (hence turn off lights when winching or jumpstarting). ignition system requires 12 volts, same with fuel injection system and your starter is drawing all it can thru a bad connection. you're correct on resistance.
clean all terminals, to the battery, power and ground to body, chassis and drive train, make sure your battery is well charged (12.6 volts) and try again. also check your coolant temp sensor, it acts the role of a choke and could cause hard starts.
 

·
Premium Member
Joined
·
103 Posts
Was there a resolution to this problem?

My wife's 1997 D 90 has had a similar problem for the past 4 years. 2,3 and 4 years ago the issue miraculously cured itself after a short time. She didn't have the problem for about 18 months. However, since February of this year it has been prevalent.

Early on she would just try starting it several times until it finally started.

The starter cranks strong.

This year I had her wait to hear the fuel pump kick on before continuing on with starting. Sometimes it would take 6 tries before you hear the pump kick on then it starts and runs just fine.

New Battery and fuel pump last month. The shop says there is power through the system to the pump and the grounds are good but the problem persists.

Anyone else have this problem or ideas of what is causing the hard start and the delay of the fuel pump kicking on?

Thanks
 

·
Premium Member
1994 D90 ST
Joined
·
866 Posts
Discussion Starter · #13 ·
No I am still having the issue. I am pretty sure it is spark related but I am not really sure where to go from here. I have run new grounds and cleaned up the contacts and it doesnt seem to make any difference.

I can hear my pump kick on right away and it does it every time. This is also an issue hot or cold, so I am kind of at a loss.
 

·
Premium Member
Joined
·
1,490 Posts
No I am still having the issue. I am pretty sure it is spark related but I am not really sure where to go from here. I have run new grounds and cleaned up the contacts and it doesnt seem to make any difference.

I can hear my pump kick on right away and it does it every time. This is also an issue hot or cold, so I am kind of at a loss.
Bill, I was under impression this issue had been solved, my 95 classic left me stranded about 1/2 dozen times and returned on tow truck another 3 times, all of these because of lack of spark or weak spark. I always thought my fuel pump would have been the culprit.
I replaced everything but the actual dizzy more than once and issues would disguise only to rear again. finally decided to replace distributor with upgraded aftermarket unit, the prices were not convincing enough while still relying on same old technology of many rotating parts, cap rotor and curve adjustments.
while researching ignition systems I came across Triggerwheels.com I liked what I read at 2/3 the cost of a new dizzy, no more caps, rotors, timing lights, vacuum advance, timing curves, dwell angles, etc. read about it and it piques your interest, ask away, I am happy with the outcome. I used the remaining funds to upgrade wires and coils.
read and get back to me with questions.
 

·
Premium Member
1994 D90 ST
Joined
·
866 Posts
Discussion Starter · #15 ·
I appreciate it but I just put a new dizzy in it which also had the remote ignition module. I am gonna look at the coil next. I currently have two problems. One is the hard start, cold or warm. Second is after about 25mins I throw an O2 sensor check engine. Gonna try to work on both of those this weekend. I do appreciate your help though and will check out the link regardless.
 

·
Premium Member
Joined
·
1,490 Posts
how are you diagnosing engine, rovergauge? let me know what the sensors are doing, they are consumable items just like spark plugs. replace at about 80k miles. once engine is a normal operating temp they switch between minus and plus when working correctly.
it is a fairly fast switch thus if switching is slow or not occurring at all or possible freezing, the sensor is bad and the engine soon light comes on. replace them as a pair.
other possible reasons for sensor code, false air aka unmetered air or air the maf is not reading. meaning a vacuum leak. intake bolts work themselves loose, plenum loose, intake boot leak, unlikely but possible over-fueling.
 

·
Premium Member
1994 D90 ST
Joined
·
866 Posts
Discussion Starter · #17 ·
Well I throw a code and it was either 44 or 45 I believe. Engine seems to run great until then. The O2 sensors only have about 6k on them, so I was hoping it was just one bad one. I am going to run them until they throw a code and then switch them and run again until the code throws and see if the code switches to the other side. I do have rovergauge though too.
 
1 - 17 of 17 Posts
Top