crank-crank-crank-crank-cra... [wait...] crank-crank-START!

[iBran]

Problem: '94 Cherokee has trouble with cold starts.

* It will crank and crank and crank if you just get in and turn the key. It sounds like it wants to start, but just can't.

* If I let it crank a few times, turn the key back to "run", and then to "start",
-OR-
* If I give it some gas while it's cranking,
it'll start up, but idle really rough, and I have to give it gas to keep it running. After a few revs with the pedal, it's fine.

* If I just turn the key to "run" and leave it there for ~20 seconds before turning it to "start", it usually starts up just fine.

Another clue: This all started after my Jeep was involved in a (minor) rear-end accident. The tank area wasn't damaged; only the driver's-side corner of the rear bumper was hit at ~20 MPH by a Honda Civic as I was slowing down to make a right turn.

I think it's the fuel pump. Maybe things back there got shaken up just enough to cause the pump to go bad? My friend says it could be the regulator and/or filter as well.

Anyways, first question: Where's the regulator?
Question B: Wouldn't the pump make some whining/squealing noise if it were going bad?
III: What else could be wrong? CPS?

 

[footdale]

Problem: '94 Cherokee has trouble with cold starts.

* It will crank and crank and crank if you just get in and turn the key. It sounds like it wants to start, but just can't.

* If I let it crank a few times, turn the key back to "run", and then to "start",
-OR-
* If I give it some gas while it's cranking,
it'll start up, but idle really rough, and I have to give it gas to keep it running. After a few revs with the pedal, it's fine.

* If I just turn the key to "run" and leave it there for ~20 seconds before turning it to "start", it usually starts up just fine.

Another clue: This all started after my Jeep was involved in a (minor) rear-end accident. The tank area wasn't damaged; only the driver's-side corner of the rear bumper was hit at ~20 MPH by a Honda Civic as I was slowing down to make a right turn.

I think it's the fuel pump. Maybe things back there got shaken up just enough to cause the pump to go bad? My friend says it could be the regulator and/or filter as well.

Anyways, first question: Where's the regulator?
Question B: Wouldn't the pump make some whining/squealing noise if it were going bad?
III: What else could be wrong? CPS?

I have similar symptoms off and on. I think that it can be classified as a "Jeep thing." The fuel line lose the pressure when it is off, so (as you mention above) leave the ignition in the "run" position until the fuel pump turns off (you'll hear it). I replaced the CPS about a year ago and it still happens to me, maybe less frequent than it used to. I wouldn't worry about it unless it fails to start.

 

[XgeekstarX]

that twenty seconds before it starts is your fuel pump building up pressure. with my xj when you cut the key on you can hear it buzz for a second or two as it builds up. yours is probably just shot and is taking a long time to build up pressure to the injectors.

i'd put a new fuel pump in it and while you're under there might as well put a new fuel filter in too.

 

[dizzymac]

sounds like normal Jeep thing, try turning key to "run" twice then try starting, I NEVER use my gas pedal while cranking. These turn a few revs. b-4 staring anyway, normal.

 

[Toph]

Sounds like a fuel pump on it's way out to me.

Just my .02

 

[MAP]

You need to get a fuel pressure gauge and check the pressure when you experience the symptoms.

Old spark plugs will also give you similar symptoms.
But if this started right after your accident, then the fuel pump does seem like a possibility.

MAP

 

[rickoregon]

Having been into the fuel tank on our '89 XJ recently I've seen how the 2" transfer hose could easily become dislodged by your 20mph quarter corner impact. Especially if it's getting old.. Or the screen "sock" filter that connects to the fuel pump inside the tank may have become dislodged allowing junk from the tank (and the outside of the sock filter) to go inside your pump, partially plugging the pump and/or fuel filter. Of course, this possibility assumes the fuel system on your '94 is the same as on my '89, and that I don't know.. The pressure test that MAP suggested would give you a clue. Hope this helps. Later, Rick

--
Rick & Kate Johnson
Venice Ranch, Burns, Oregon 97720
http://home.centurytel.net/venice/

 

[Matthew Currie]

Sounds like a fuel pump on it's way out to me.

Just my .02

Could be, but not necessarily. The check valve can go long before the pump itself. Mine has been doing it for the last 100 thousand miles or so (245k on the original pump). I just wait before I crank. My other car is a diesel, so I'm in the habit anyway.

 

[jlex]

On my '98 there's a check valve on the fuel pump & on the filter/regulator. Someone posted that if they go bad, you can get an in-line check valve to keep the pressure in the line for the next startup. May want to search check valve. I think they said they used a BMW in line check valve.
jlex.

 

[Mestopin]

Here's the part number

"The BMW fuel check valve part number 16 14 9 068 988

This is the part number I used to purchase the valve from Momentum BMW in Houston. Someone from JU said their BMW delaer couldn't find the part with this number.

Also, I paid $2.67 but I believe the price has gone up some.

Here's the link with some pictures from the JU writeup

http://www.jeepsunlimited.com/forums/showthread.php?t=640146&highlight=long+crank

By the way, it's been almost 4 months now and I still crank almost immediately (1/2-1 second).

Mark
91 XJ 126k

 

[KingA]

I had problems starting my 87 that were similar to that. The distributer needed to be re-indexed. Solved the problem..

 

[kawijames]

replace the fuel pump and regulator as a pair. my 91 had the same issues as you are describing. after checking my FP i found that initially i had 5 psi but after 15-20 seconds the pressure had increased significantly. remember that when your pump is on its way out many times( not always) this puts strain on the diaphragm in the FPR. just helpful advice

 

[iBran]

My buddy is available this Friday to help me replace the pump.
Anyone have some tips/pointers to make this thing go smoothly? I've never done a fuel pump, let alone drop the tank. He's helped somebody put a new pump in a ZJ, which I would assume is the same.

One question:

- Autozone has two pumps available, a "short style" and a "long style".
Anyone know what "style" a 1994 with the 4.0L would have?
I'll probably go to Napa, but just wanna be prepared in case they ask the same question.

And yeah, we'll definitely do the filter and probably the regulator as well.

 

[iBran]

Bump! If nobody has anything else to say, I'm gonna assume this thing is gonna be a piece of cake. Hope so!

 

[Alienspecimen]

Bump! If nobody has anything else to say, I'm gonna assume this thing is gonna be a piece of cake. Hope so!

Wait...:wave:
I have something to say.
I think that your tip about being rearended gave it away and this might stop this nasty "Jeep thing" rumors.
I had longer starting times recently. It started after my hanger on the back, right where the muffler is rusted out and the whole back end of the exhaust was not supported and was vibrating slightly. Fixed it and that fixed my problem.
Apparently loose exhaust system can cause longer starting times.
Boris

 

[iBran]

Wait...:wave:
I have something to say.
I think that your tip about being rearended gave it away and this might stop this nasty "Jeep thing" rumors.
I had longer starting times recently. It started after my hanger on the back, right where the muffler is rusted out and the whole back end of the exhaust was not supported and was vibrating slightly. Fixed it and that fixed my problem.
Apparently loose exhaust system can cause longer starting times.
Boris

No way! I'll have to look at that... I know I have not just one, but TWO broken hangers. I've been meaning to fix those, too, but my priority is the pump. I'll give the exhaust a good lookover while I'm working on the pump.. I know I need a new muffler anyway

 

[muduck18]

Wait...:wave:
I have something to say.
I think that your tip about being rearended gave it away and this might stop this nasty "Jeep thing" rumors.
I had longer starting times recently. It started after my hanger on the back, right where the muffler is rusted out and the whole back end of the exhaust was not supported and was vibrating slightly. Fixed it and that fixed my problem.
Apparently loose exhaust system can cause longer starting times.
Boris

snif snif snif ..... Bull $h1T


so when the jeep is warm it the tail pipe holds still on it's own... or does the trunk monkey come out and grab it for you?

 

[Vertisce]

I had that issue when I first bought my Jeep...thought it might be an electrical issue...bad ground or whatever. Turned out to be a bad starter though.

 

[Alienspecimen]

snif snif snif ..... Bull $h1T


so when the jeep is warm it the tail pipe holds still on it's own... or does the trunk monkey come out and grab it for you?

I looked first for a weather pattern, but did not find any...then noticed that the louder the rattle at start, the longer the starting times. Mounted a new hanger and problem solved. My mechanic tried to give me the scientific explanation, but it went over my head, coz I am still learning RI accent and I did not care that much, anyway...things behave differently when hot.
Boris

 

[muduck18]

I am sorry, No offence, but the muffalar system doesn't swing differntly when it's hot. and yes the jeep will start differntly when its warm.

BUT.....
there is absolutly NO connection between the delayed start so notorius in the 4.0 and the rear tailpipe bracket. There are three other brackets to hold that beast in place...
for two weeks my header went straight out the side of my passenger side of my jeep... no problems starting.

your RI mechanic needs to call me and explain his theory to me before I will change my BS claim on that one...

in the mean time...