Fuel system problems ?

Ok,
I have a 1999 classic 4 dr with 120,000 miles on it that is my daily driver. Last year the TPS and both O2 sensors where replaced. I has some problems that are progressively getting worse. When I try to start the thing it will turn over about 16 times before it will finally start. This I beleive is a fuel pressure leak some where in the system. Because if I cycle the ignition 2 or 3 times before trying to start, it will prime the system and start right up. I don't know where to start with finding this leak, if that infact is whats going on. The next problem is... When I go to accelorate the engine boggs down as if it's not getting fuel for about 5 seconds and then it will regain power sometimes with a small pop of back pressure out of the intake. This useually happens when I first take off , but it dose sometimes do it after it has been driven for a while. The final problem is the belt squeeling. It is loud and lasts a long time. It is alot worse and more prone to do it if the AC is on or the defrost. My question is where should I start with fixing these problems??? Any help would be awsome.
Thanx, Mike :banghead:

You should connect a fuel pressure gauge to the fuel rail. The fuel rail should be pressurized at all times. Or you could just check to see if there is any pressure by pressing the relief valve at the end of the fuel rail. Do this with the engine off. Be aware of spraying fuel. There should be fuel spraying out, if the pump and valves are ok.

Regards Torfinn

Mike, we missed you in Moab......guess this is why? The squealing belt could be lack of proper tension, defective idler pulley, or bad belt itself. Are the alternator, PS, AC, waterpump all working properly?

As for the hard start, could be the CPS signal.....but I had this problem years ago with my 89 and it wound up being the pickup in the distributor was out of sync.......the pop or backfire through the intake usually indicates a timing problem, which could be CPS related as well. Wish I had a solid answer, I can recommend a good mechanic though. Hepworth Automotive on 12st below Wall in Ogden, tell Roger that I sent you over.
Jeff

I'm not sure about the middle one (though I'd look for vacuum leaks first), but for the first, the leak is likely in the fuel pump itself, where there is supposed to be a check valve. It's your choice whether or not to fix it, because it shouldn't affect running once you start. My 95 is similar, and I just wait a few seconds after turning on the ignition before I crank. I believe some people have had good luck adding a check valve in the line. You might do a search of the forum for this, because I think there's a BMW valve that has been used with success.

For your belt, the first thing to do is investigate carefully to see if the pulleys are all right. Check especially the idler, which can wear out, and watch the crankshaft pulley as it rotates to see if it wobbles. The rubber in this pulley/vibration damper sometimes deteriorates. If all the pulleys look good and the belt looks good, check for tightness. As a quick check, try twisting the belt (at the top span where there's a long unsupported length). It should be just possible to twist it 90 degrees. If it's fairly easy to twist farther, it's too loose. Ideally, you should use a tension gauge. NAPA sells something called the KRIKIT II, though you might have to inveigle your local napa guy to look in the catalogue to convince him it exists. It's fairly cheap, under 20 bucks last I knew. Tension for a used (more than 15 minutes old) belt is 140-160 lbs. This is quite tight, and if you're not used to serpentine belts, you'll be surprised how tight it is. A loose belt can be troublesome. My old 87 never squealed, but when it wasn't tight enough, it developed power steering "pump catch" which was very scary in an emergency maneuver.

wow...i have the exact same problems with my '90 4L....except the belt squeak...
i've been waiting to post a question with my problems though until i tried a few mroe possible remedies.....i've got a tick in my injectors and it's probly time for new ones anyways (this jeep was trashed beyond recognition when i got it last summer).....but, new fuel filter didn't help...old one was terrible....i wanna look into the pump....possible clog or somethin not right...but haven't had a chance....
about the only way i've found to avoid bogging down on acceleration is to punch the accelerator...if i keep the RPMs over 3k it doesn't seem to bog....
if anyone else has any possible solutions i would love it as well....

as for my input on the squeaking belt...on my old XJ, (1989 4L 2wd stock) the belt squeak it gain years back was actually something with the crank pully....causing the belt or the pully to rub the front of the engine block without showing any signs of rub wear on the belt. i don't remember exactly what it was because my dad found it and fixed it, after the year or two of exsessive squeakiness.....but maybe that'll help you some...??

Break down and pickup a new belt and new idler pulleys from the dealer. The only PIA part is loosening the idler adjuster pulley, you need a 15MM long kind of offset wrench for that one. One of my friends gave me a snap-on one thats about 2ft long and does 4 different sizes. You can also remove the aux fan and get a socket in there too but thats why I hunted around for that pulley wrench. Careful of the fan connector, it has TWO locks on it then just lift it out of the way. Remove the old pulley and install the new one then install the new belt. Use the krikit II to set the tension. New belt gets cranked up to 180-190lbs and man that puppy is TIGHT. The krikit looks like a gadget and has a pen clip for your pocket, play with it for a while till you figure out where to put your fingers to get it to give you a good reading.
As for the hesitation when mine does that it's telling me it's time for a FI cleaning which includes a good off the manifold throttle body cleaning on the work bench or a good spray down. I just found a new TB cleaner from Gumout called 'Air intake & throttle body cleaner' it is in a grey can/black lid. It says it won't remove protective coatings but warns against spraying across MAP sensors. I used half the can and it did a good job of cleaning the carbon out of the TB and at the bottom of the intake manifold. I also use Chevron Techron and once a year I use the 3M injector cleaning kit that plugs into the fuel rail and has it's own cleaner/fuel can.
I got a much closer look at the fuel pump area on top of the tank today while the auburn was going in. There is no way that fuel pump can be changed on the 97+ w/o dropping the tank at least not with a 20gallon tank. Mine also has started doing the 4 second crank before firing so I did the 'turn to on and wait 15 seconds' then it fires right up so I guess my drainback valve in there is going. May end up replacing it which should fix the problem and as an added benefit my fuel gauge may actually work again instead of waving at me... I think that with mine at ~195,000 mi it's time to do the O2 sensors too...

I had a long crank time on my 91 XJ. Found a service bulletin at Alldata. It said to change the hose and clamp from the pump to the tank outlet. It gave part # but the dealer here had no record of it. I changed the hose and put a new clamp on and it was a lot better, although it seems to have got a little worse now. Wish I had double clamped it. Its not to bad a job to pull the pump.