Fuel Pump?

[5-90]

This is really annoying. OK so exactly how do I Press the fuel pressure release valve on a 97 I6? I dont have the FSM but Chiltons guide says I need a guage to check pressure and that the TBI system releases fuel pressure when the system is off? I was hoping to find the valve somewhere. Am I confused that it doesnt have one? And yes i havnt looked as its the middle of the night and im happy sitting here and will check and look around in the morning but thought i would put that out there.
This last time it happened it was sitting in the driveway and had been driven 2 days before with no problems. Although come to think of it i came out to a nearly dead battery and nothing was left on [new optima yellow top] trickle charged it and now it holds the charge fine but i can only turn it over. so maybe if i can check the fuel relay? maybe it fried itself on or something and drained the battery? Well now im talking out loud about something I dont know is possible so sorry if thats horribly NEWB... HELP!

For starters, you don't have "TBI" (Throttle Body Injection) - you're a lot closer to "PFI" under one of its various monikers ("Port Fuel Injection" - with one injector for each cylinder.) So, ignore the TBI section of the manual, it don't apply.

Check the fuel rail feeding the injectors - opposite the injector bungs, there will probably be a Schrader-type valve with a cap on it. That is the fuel pressure test port, and that is where you'll connect the pressure test gage. On RENIX, it's toward the front of the fuel rail (but I'm not sure where it is on HO, offhand.) A decent fuel pressure test gage should run you $30-40 - I think the K&D I picked up years ago ran me about $30. Whatever you do, make sure it's FUEL RATED!

I don't have my FSMs to hand at the moment (damn moving...) but I'm sure someone will have one in your year if you haven't, and can help you identify components and get some tests ginned up.

 

[aroncull]

OK i think that i have seen said schrader valve, its covered with a black screw on cap, on the fuel rail. Is there a pressure release valve for my "PFI" system. im hoping to do a quick test to see if the pump is working at all. then maybe i could save the $30 and spend it on the pump if i have to.

Thanks

 

[5-90]

OK i think that i have seen said schrader valve, its covered with a black screw on cap, on the fuel rail. Is there a pressure release valve for my "PFI" system. im hoping to do a quick test to see if the pump is working at all. then maybe i could save the $30 and spend it on the pump if i have to.

Thanks

The pressure test port can also double as a pressure release valve - make sure to use plenty of rags, and use a small screwdriver to push the pin.

 

[aroncull]

Awesome Jon thanks..

Good night..

 

[aroncull]

Ok guys, getting plenty of gas it would seem. I released the gas at the fuel rail through the release valve. 1st i emptied it and then i had a friend push in the valve while priming and starting/ plenty of gas came out but i only needed 4 paper towels or so to catch it as it came out. Then we switched it out and i caaught the gas that time. same results. i checekd all connections..
Recap

I have a new battery, with [currently] plenty of charge. i have it trickle charging just to keep it at level.
I have plugs less then a year old [bosch] gapped at i think 40 something.
I have accel super stock Coil [most recent addition at 6 months or so ago]
Accel 8MM SS wires put in the same time as the plugs.
Accel SS Rotor and Cap about 9 months ago.
I have All new battery harness wires [ Thanx 5-90 ].
I checked and rechecked the connections all seem fine , unless there is a hidden cut or frayed wire].
Just put in a new CPS [but i realized that i had reconnected the battery before i connected the sensor, but in the chiltons it specifically doesnt say you have disconnect the battery...yeah right]

Also have new TPS

Symptoms.

Jeep turns over with no problem but never catches. have about a 1/4 of a tank of gas.
Not sure how much gas should be coming out of the pressure valve on the fuel rail, but as i mentioned above i get about 3 to 4 paper towels worth.

Is there a Relay i should check?
Also next on my list is to check for spark, sound right?
Any other ideas?
Is there another sensor i should check?
trying to catch this gremlin instead of the local NAPA shop.

-Aaron

 

[aroncull]

Well i borrowed a spark plug tester from my nieghbor.

I see no spark.

I assumed that i was sopposed to SEE the spark at the end [looks like a cone sorta] it was properly grounded as i tried a few different spots and plug wires including the one off of the coil itself. I assume that that was the correct way to test the spark, i have not done it before.

OK so assuming its the lack of spark now i will attempt to search that subject, any advice is welcome [DUH!]

Thanks guys!!

Aaron:bawl:

 

[5-90]

Turn the key on, and see if you have +12VDC at the coil primary. The spark "fires" when the coil primary is "turned off" (the magnetic field collapses, inducing a current in the secondary windings, firing the spark, ...)

Since you did not get spark directly from the coil, that's where I'd go next. Just work your way backwards along the circuit.

I think I have a similar spark tester - it has a large crocodile clip for a ground, and a "spark plug terminal" up top - and the air gap can be adjusted, no? I usually just plug it into a wire under test, clip the thing to ground, and then use a bump switch with the key ON to crank and see if it sparks. Not much else to it, really...

 

[aroncull]

Ok will do, Primary you mean the Harness connection end, going into the Coil..i presume.. sorry if its obvious but i learned early on its best to be clear and sure. If the Coil is good what would be your next suggestion. Please

Thanks
Aaron

 

[aroncull]

Well I am getting current at the Coil harness it varies from 2 up to 14 or so.. sorry it had just started to rain and 2 of my boys where going nuts and trying to climb in there with me [6 and 3.5 yrs old] so I didnt write it down. How much current should it get? Is it safe to bet the Coil is bad, It is aftermarket and I have the old one laying around.

Does anyone know.. to test this could I just plug the other coil in and not bolt it to the block.. does the block offer ground? or something else possibly. This is on a 97 where the coil connects to the block through the metal stacked around the outside.. i assume this metal is the field producing coilinator thingy... sorry, had to LOL.

 

[aroncull]

Well I am getting current at the Coil harness it varies from 2 up to 14 or so.. sorry it had just started to rain and 2 of my boys where going nuts and trying to climb in there with me [6 and 3.5 yrs old] so I didnt write it down. How much current should it get? Is it safe to bet the Coil is bad, It is aftermarket and I have the old one laying around.

Does anyone know.. to test this could I just plug the other coil in and not bolt it to the block.. does the block offer ground? or something else possibly. This is on a 97 where the coil connects to the block through the metal stacked around the outside.. i assume this metal is the field producing coilinator thingy... sorry, had to LOL.

Here is my current Coil.. why or how could it die?

http://store.summitracing.com/partdetail.asp?part=ACC-140021&view=2&N=700+

 

[5-90]

Well I am getting current at the Coil harness it varies from 2 up to 14 or so.. sorry it had just started to rain and 2 of my boys where going nuts and trying to climb in there with me [6 and 3.5 yrs old] so I didnt write it down. How much current should it get? Is it safe to bet the Coil is bad, It is aftermarket and I have the old one laying around.

Does anyone know.. to test this could I just plug the other coil in and not bolt it to the block.. does the block offer ground? or something else possibly. This is on a 97 where the coil connects to the block through the metal stacked around the outside.. i assume this metal is the field producing coilinator thingy... sorry, had to LOL.

Correct - "primary" is the low voltage side, and "secondary" is the high voltage side. Primary voltage should be right around "source" voltage - battery (~12.6VDC) with the engine off, and alternator output (~13.5-14.0VDC) with the engine running. However, with the engine running it's "interrupted DC," and better read with an O-scope.

You can fire a single spark from the coil by grounding it to the engine, and using a patch lead to connect the "hot" terminal to the battery + post. Disconnect the "hot" lead to fire the spark - you shouldn't get anything until you remove either end of the lead, but you should be able to get a nice fat spark once you do.

Go ahead and use the coil wire and stick a spark plug in it to check - and just rest the ground strap of the plug against the engine block.

This is a function test of the coil only - you can also check the coil windings with an ohmmeter, but I don't recall the specs. Either test would be valid.

 

[aroncull]

I Got it to WORK!!!

I tested the Accel Coil again and it failed.
I swapped in the old OEM Coil and it fired right up...

Any ideas as to what would cause a Coil failure?
I did come out to a drained new Optima yellow top battery 2 days before this happened. I had not left anything on as i checked..

thanks guys!

Aaron

 

[aroncull]

OK IT STOPPED WORKING AGAIN!!

I get current from the coil but non at the plugs...

Sorry guys I dont know whats going on here.

Swapped the old OEM coil in and it worked great, drove it around a bit a couple of times.

Now it wont start again, just turns over. Battery reads 14.1 and the coil at the rotor/wire side shows 12+. I tried to read the measurment at the wire and plug end and it seemed like nothing was there. Then my clutch fan ate the red wire for the multimeter :gonnablow im tired of this..

Any help appreciated.

-Aaron

 

[aroncull]

BUMP! Help!!

Anyother suggestions? not the coil, not the CPS, not the fuel pump... whats next?

 

[8Mud]

Could be a CPS problem, but just for the heck of it the next time it quits try starting with about 1/8th pedal.
The IAC was sticking in the wifes 96, actually stuck shut. No air no start, eventually it will flood.
It also would occasionally stall at idle.
I spray some sort of spray oil into the IAC *air in* port with the motor running. I use some German stuff that is rust dissolving and oils (lubricates) at the same time. It seems to do the best job, it's made by Henkel so there is likely an American equivalent.
I spray into the IAC port a couple of time a year in both my 88 and 96 and the IAC problems (high idle or stalling) seem to have disappeared on both for the most part.