stumble,pop,chug chug.....

JYoung

Member
Apr 18, 2005
12
0
HOWDY! :)
I've been having some "issues" with my 95 Disco and I need some guidance. First off, replaced fuel filter last year, along with new fuel pump. A few months ago I started loosing power in the middle of the powerband. The check engine light has always been on...can anyone tell me how to read the codes? Autozone is clueless... I'm getting a loud rapid popping type backfire that sounds like it's coming from the airbox when the engine is placed under load. A few days ago I started to experience a weak start situation, turn the key and engine starts but sounds like its stumbling then catches up and runs normal. Since then it failed to start twice, engines turning over like normal but not starting. After a few trys it starts up like nothing is wrong. Before I replaced the fuel pump last year, it was acting similier with the no start situation but with the popping and loss of power could it be something else this time? Thanks for the help!
 

jsonova99

Well-known member
Apr 14, 2005
1,683
0
47
Snow Hill, MD
JYoung said:
HOWDY! :)
I've been having some "issues" with my 95 Disco and I need some guidance. First off, replaced fuel filter last year, along with new fuel pump. A few months ago I started loosing power in the middle of the powerband. The check engine light has always been on...can anyone tell me how to read the codes? Autozone is clueless... I'm getting a loud rapid popping type backfire that sounds like it's coming from the airbox when the engine is placed under load. A few days ago I started to experience a weak start situation, turn the key and engine starts but sounds like its stumbling then catches up and runs normal. Since then it failed to start twice, engines turning over like normal but not starting. After a few trys it starts up like nothing is wrong. Before I replaced the fuel pump last year, it was acting similier with the no start situation but with the popping and loss of power could it be something else this time? Thanks for the help!

I'm not realy sure what your problem is, but I'm wondering if this is realted to the carbon buildup issue in the heads, I'm curious to see what others have to say. I've gotten paranoid about this problem after reading a bunch of posts about it.
 

JYoung

Member
Apr 18, 2005
12
0
Hopefully someone will have some good advice. I'd hate to just start replacing things to see what is not working properly. I'd love to see what codes it's throwing so someone please let me know how to read them.
 

Robbie

Well-known member
Apr 20, 2004
1,463
1
NOVA
a '95 is OBDI. you have a code reader under your passenger seat. little black box that has red leds to show the code. once you check the code, compare to here: http://www.fourfold.org/LR_FAQ/RR/FAQ.Engines.Fault.Codes.html

when was the last time for tune-up? plugs, wires, cap, rotor? been through any water recently? have you checked fuel pressure at the schraeder valve on the fuel rail?
 

warner0188

Well-known member
Jun 1, 2004
46
0
48
Concord, NC (Near Charlotte)
I have virtually the same symptoms. I have a 1996 Disco 4.0. Your popping sounds like what mine does after I spray the engine at the car wash. I sprayed under the hood (which is kind of stupid anyway) it barely started and when did it was sputtering for about 20 minutes. I had to sit at the car wash and wait until it dried out.
My main problem is that I have trouble at times under acceleration. It will get around 3-4k RPMs and just flatten out. If I floor it it just stops accelerating and the tach stays right there. When I let off and the RPMs drop back it continues on unless I get the RPMs back into the 3k range. When I go to start the truck, most of the time it takes several seconds of the engine turning over for it to start up. I used to smell raw gas at this time which was kind of scary. I got the fuel tank replacement the other week and the raw gas smell has gone away but it still stumbles and is hard to start. What is wierd is that neither of these symptoms are always present. Sometimes, it will crank right up and I can drive it and it will run perfect. Then if I stop at the store, try to start it and the symptoms are back. I have also replaced the plugs, wires, catalytic converters, fuel filter, oxygen sensors. I did Seafoam twice in the gas tank and once through the vacuum line and once in the crankcase to try to clean out and carbon deposits. I replaced the battery and some other things I can't recall right now.
I took it into the shop yesterday and my mechanic told me there was a cam or crank shaft position sensor code, a random misfire code and some sort of ignition module code. He is leaning towad the position sensor. I can't remember if he said cam or crank (sorry). I'll let you know if we get it figured out. It may help you.
 

jsonova99

Well-known member
Apr 14, 2005
1,683
0
47
Snow Hill, MD
warner0188 said:
I have virtually the same symptoms. I have a 1996 Disco 4.0. Your popping sounds like what mine does after I spray the engine at the car wash. I sprayed under the hood (which is kind of stupid anyway) it barely started and when did it was sputtering for about 20 minutes. I had to sit at the car wash and wait until it dried out.
My main problem is that I have trouble at times under acceleration. It will get around 3-4k RPMs and just flatten out. If I floor it it just stops accelerating and the tach stays right there. When I let off and the RPMs drop back it continues on unless I get the RPMs back into the 3k range. When I go to start the truck, most of the time it takes several seconds of the engine turning over for it to start up. I used to smell raw gas at this time which was kind of scary. I got the fuel tank replacement the other week and the raw gas smell has gone away but it still stumbles and is hard to start. What is wierd is that neither of these symptoms are always present. Sometimes, it will crank right up and I can drive it and it will run perfect. Then if I stop at the store, try to start it and the symptoms are back. I have also replaced the plugs, wires, catalytic converters, fuel filter, oxygen sensors. I did Seafoam twice in the gas tank and once through the vacuum line and once in the crankcase to try to clean out and carbon deposits. I replaced the battery and some other things I can't recall right now.
I took it into the shop yesterday and my mechanic told me there was a cam or crank shaft position sensor code, a random misfire code and some sort of ignition module code. He is leaning towad the position sensor. I can't remember if he said cam or crank (sorry). I'll let you know if we get it figured out. It may help you.

sounds expensive, good luck!
 

JYoung

Member
Apr 18, 2005
12
0
New plugs last year, thats it. Thanks for the link to the codes, I will post the results this evening.
 
M

mkronmal

Guest
For Jehremy (SP?)

When was the last time you replaced your ignition wires? Your symptoms sound a heck of a lot like an arcing issue from bad wires. Do you happen to hear a tic-tic-tic when your engine is running, sort of like a stun gun?
 

JYoung

Member
Apr 18, 2005
12
0
Just read the code, #48, stepper Motor. There are no popping noises from the wires like a stun gun. I will have to check the engine compartment when it dark out to see if I can see arcing. What is the normal fix for a code #48?
Thanks!
 

JYoung

Member
Apr 18, 2005
12
0
Just got off the phone with advance auto parts, $199.99 for a new IAC valve, suggestions? Could this cause the intermitant no-start problem and the lack of power?
 

JYoung

Member
Apr 18, 2005
12
0
Ok, just found the stepper, janked it out and cleaned it. Found it to be very gunked up with carbon deposits. The three screws were just hand tight too, might have has an air leak there. Cleared out the code 48, CEL went out and test drove for about ten miles and hasn't came back on yet. After cleaning the stepper, the engine started at 2000 rmp then stepped down to 1500 rpm then 1000 then settled at around 750ish. for some reason the disco seems to have some more power and runs smoother? Mind trick or can this actually help that? I still have the rapid popping noise (backfire) at heavy acceleration at around 2500 rpm. 48 was the only code that was thrown.
 

geoff

Well-known member
Apr 23, 2004
164
1
Austin, TX
Popping sounds can be caused by incorrect timing. The obvious stuff needs to be attended to first - plug wires and distributor cap. Next get a timing gun and check that your timing is 6 deg BTDC at idle. Try and get the timing gun as close to verticle over the crankshaft pulley as possible. The number 1 plug wire can be located using the diagram under your hood or in the owner's manual.

Use a white crayon or chalk to highlight the 6 BEFORE TDC on the crank pulley markings. You can adjust the timing by rotating the distributor after loosening the hold down bolt in the block.

Could also be a plugged fuel filter or bad fuel pump causing a lean condition under load. I know the carburetor on my boat is too lean when same happens.
 
E

EXPetrush

Guest
a good tune up wouldn't hurt.. probably needs it.. plugs, wires, cap, rotor. check for any vacuum leaks. the fuel rail has a tendency to get plugged & rot out. Also might pull an injector & check them out.. chances are they are due for replacement. the clogged stepper motor will cause lots of idle issues, also wouldn't hurt to run an intake cleaner thru .. BG or sea foam products both do a good job & are do it yourself.
 

JYoung

Member
Apr 18, 2005
12
0
Ok, will replace those items and check timing. What is the best source for them? Atlantic British has been good so far, just wondering if there is someplace cheaper. Could the intermittant fail to start be attributed to the cap/router? THanks for the input!
 

JYoung

Member
Apr 18, 2005
12
0
You know, I was checking out the MAF a few months ago and the wire mesh piece looked like it was coming apart. There was a small hole in the screen near the bottom. Could this be part of the problem? I'll have to pull it out and check it again to see if its gotten worse.
 
D

DiscoInferno Tampa

Guest
My 97 also has the rapid 'popping (almost a pinging-type sound)' that sounds like it is coming from near the airbox. I have changed the plugs and wires, replaced the fuel filter, cleaned my MAF, and used fuel injection cleaner to no avail.

I am not throwing any codes at all. Have no idea where to go next. Any ideas?