gonzvj
Member
Nope, it start with no black smoke.
When the ambient temp is above 45 degrees it starts at the first time.
No more Bosch fuel pumps produced. What is the next best?
- Thread starter garagecouple
- Start date
When the ambient temp is above 45 degrees it starts at the first time.
I'm sure this was already covered but I'm being too lazy to search the thread. Will it start right up if you prime the fuel system (cycle the key on and off without starting) a few times?
Maybe you could temporarily splice in a check valve (as close to the tank as possible) to either isolate or eliminate the one in the pump assembly? this would add a redundancy and would tell you for sure if fuel is draining back into the tank...and its cheaper and less labor than replacing the unit (again).
Example link
Although, because this only happens when its cold is making me think there is something else too it. the fuel would drain in hot weather also.
Example link
Although, because this only happens when its cold is making me think there is something else too it. the fuel would drain in hot weather also.
gonzvj
Member
The colder it gets, it needs more tries to start. After the engine warms up it start at first try every time.
gonzvj
Member
Sorry I forgot to add this info, I did install a check valve before the tank. I made a hose with the check valve and quick connectors. And I agree with you about happening only on cold weather.
Sounds like a choke...but fuel injected engines don't have a choke. Which sensor tells the engine that's its cold and needs the "choke to be closed"? Air charge temp sensor? Maybe the computer thinks its warmer out than it actually is...
I absolutely hate throwing parts at a fix (shotgun maintenance), but some sensors are not "bad" enough to throw a code...and they are relatively cheap at under $20.
rubber hoses get hard when it's cold. Wonder if you have a tiny leak at a hose clamp somewhere that's just big enough to bleed off some pressure and only when it's cold out.
gonzvj
Member
gonzvj
Member
A mention of that probably would have headed off all the pump assembly leaking talk and saved you a few bucks...oops
. I think the focus should be on electrical/sensor, something is telling the engine "not to start" in cold weather. Something that resets after the first attempt, kind of like the fast idle step in a carburetor, once you hit the gas it drops down to a lower idle and will run rough or die when cold.I keep using carburetor references because they are a simpler version of what the fuel injected engines do.
I'd R2 the coolant temp sensor first because it flagged. Then maybe look into the IAT sensor if still an issue.
Or do a good check of all those connectors first, maybe clean them up with electric component cleaner.
gonzvj
Member
After it starts it stayed running, no rough idle nor die. like if everything is OK. If I turned it off when it still cold, it will not start right away. but if it reach normal temp it will start right away.A mention of that probably would have headed off all the pump assembly leaking talk and saved you a few bucks...oops
I keep using carburetor references because they are a simpler version of what the fuel injected engines do.
gonzvj
Member
Right now is 27° outside.
ODBII Shows 35.6° on the coolant and 33.8° on the intake. But I found something funny, look at the video when I turn the key to the on position gauges won't move and jeep won't start. Second time gauges move a little and won't start. Third time gauges move where they suppose to be and it almost started. Fourth time it started right up.
Wow, that's discouraging.Well, I am giving up on this. Replaced fuel pump with Bosh, Mopar FPR, Fuel injectors, and the issue continued,
I have replaced the Crankshaft sensor, distributor pick up, distributor cap and rotor, ignition coil, spark plugs, also the battery was week so i replaced too, but, the issue persist.
Attached is a video of the no start with good fuel pressure at 35 Degrees temp. i can crank it all day and it will not start at first try, but second try usually works. today we are in the mid 20's and it took a little longer to start. The picture is all the parts I have replaced ( I get good discount at Napa). Good thing is, I have a lot of good spare parts.
What else is there to look at?
PLEASE HELP!!!!
View attachment 225639
The video you added is only showing up as an audio file.
gonzvj
Member
Let me try it again
I guess is to big to uploaded here but here is a Google photo link.
https://photos.app.goo.gl/AaHmHQipXPBueKAe8
It's rare for temp sensors to actually fail. Since your air temp is reading wrong (unless you're in a heated garage or something?) and you're getting sporadic readings, I would check PCM grounds and any other grounds related to your IAT sensor.
If that checks out OK, maybe your clock spring is on the way out and causing intermittent signal during key cycles?
If that checks out OK, maybe your clock spring is on the way out and causing intermittent signal during key cycles?
Sorry, I had a brain fart.
I meant to say ignition switch. Wondering if that could be causing the erratic signals during start cycles. I'd check the PCM and sensor grounds first though.
I was starting to think ignition switch or ignition relay. Something that gets "gummed up" when it gets cold or takes a few tries to get to engage. I remember working on a vehicle where the ignition cylinder had a linkage that went to a box, this was where the actual ignition switch was. It was all gummed up with dirty grease (in this case the truck kept cranking). I'm not familiar with whether or not the TJ has a remote ignition switch though.