Problem with my GTS (feels like she missing spark/fuel)

jdeft1

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Maybe not a fuel issue but a faulty ignition coilpack... or loose connection? Not sure about the viper but I've seen then go in and out before failing completely....
 

RTTTTed

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anything under 50 psi is wrong. Have you called JonB (PartsRack.com - Home) for a fuel pump? Walbro is cheap and a better pump.

Draing your fuel tank probably would have left some water/contaminents at the bottom of the tank, but then you could add fresh fuel and gas line antifreeze to dissolve the small amount of water in the bottom. I agree that removing the pump from the top and cleaning the tank is good and is the best solution, but that's a good idea for everybody with the Gen 2s, expecially the cars that get parked without fuel stabilizer for years at a time. Because it is a time consuming job, it seldom gets done. If you've got a half day - siphon etc it always the best solution, even if that's not the problem.

Ted
 

RTTTTed

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I peeled the rear carpet out of the back of my GTS and drilled out the pump access cover (top, middle). Easy enough to do and that gives you access to the pump. The cover plate rivets are 'special' and difficult to find. I used RTV and ordinary screws to re-attach the pump cover plate. If you use ordinary screws make sure that no sharp points that could punture the fuel tank in case of accident.

Ted
 

dave6666

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I have a 98 gts that has the same problem.
I did a fuel pressure test and it bounces from 40 to 80 when the motor runs like crap.i ordered a pump off a parts website but its the wrong one. going to Dodge tomorrow to order the right one. VCA member get a discount so its only 730.00

I picked up a barely used used one from Roe for like $30. Just to have as a spare. I just can't pass up good parts cheap. I have not made it past step one. I will not admit my problem.
 
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Dom426h

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*****UPDATE*****

Last weekend:
70mile trip running Fine,
25mile trip running Fine,
25mile trip running Fine,
30mile trip Fine EXCEPT for about 5-10 min she ran rough(with the original symptoms)
25mile trip ran Fine
70mile trip ran Fine
Previously when she ran bad it would be Fine after parking and shutting down. This got me to thinking that it might be something electronic resetting. WRONG. This time when she started acting up to test the theory i immediately cut the engine while still moving, then started her back up and was still running bad, then pulled over and shut down for about 5min. Restarted and she still ran bad for the next few minutes until clearing up and running Fine for the rest of the day.

This weekend:
Road her around between 1/2&1/4 tank aggressively on a very twisty backroad and even slalomed on the straights to try to mix up the tank and replicate the problem if it was fuel related. No go, she ran Fine.

Reset the ECU/ECM to have it start from square1 with fresh parameters/clearmomory. Drove Two 15min trips running fine.
Took her out sunday mornin and she started acting up after about 10min of driving. She was breakingup/hesitating for about 3-4 min before clearing up and running Fine for the rest of the day.

Another thing i forgot to mention: When this happens i can push the clutch in and rev it up no problem (aka no load - no problem). Also, when this happens its intermittent within itself meaning that pushing down on the throttle it will eventually "catch" and i can pull hard up to redline But once i shift down to lower rpm's she continues to stutter until eventually clearing up.
 

99 R/T 10

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I have a 98 gts that has the same problem.
I did a fuel pressure test and it bounces from 40 to 80 when the motor runs like crap.i ordered a pump off a parts website but its the wrong one. going to Dodge tomorrow to order the right one. VCA member get a discount so its only 730.00


Call Chuck Tator, 914-763-3136 :2tu:
 

Dan Cragin

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If you have a 96-97 GTS, check this first, Pull the fuel pump relay (in the back left rear storage area) and see if it shows signs of getting hot. Look at the fuse box plug connections and see if they are burnt. Sounds like a fuel delivery problem.
 
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Dom426h

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I've talked with chuck a few times. He recommended starting with resetting the ECU. Also since there is no CEL or pending code and the problem is So intermittent we agreed that having a scantool ready in the viper while it is out on the road would be benificial as i could record a datalog when the issue occures (every 100-200miles or so) and later analize it to see what is happening with all of the sensors. I have one picked out but i think for now im going to hold out for alittle and continue to troubleshoot with my brain:confused: (AND all of yours!:))

The fuelpump relay looked fine when i pulled it to do the fuelfilter. i'll check again though. -Thanks DC
 

sdaddy

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If the battery is four years old, I would replace it. A low charge will cause all kinds of electrical glitches that can come and go. I burnt both of my side sills from an engine missing due to inconsistent power flow to the ECM. Caused the engine to run rich and overheated both cats.

My Viper Tech did all kinds of diagnosis to determine the cause of the overheated cats and found nothing. When I went to pick up the car from him, they had to jump start it (it had been in their shop a month) and it had the same problem. Changed the battery and all rough idle issues cleared up immediately.

Batterys are too cheap not to remove that as a possibility if it is 4 years old.
 
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Dom426h

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Dave,
Actron® 9180
or
CanOBD2 Diagnostic Tool - EQUUS PRODUCTS, INC. 3130

They are basically the same thing...
They do the same thing for the same price(140shipped@Amazon) and both run 180-190 in auto stores.

Daddy,
I here you. but i am reluctant to replace a battery that checks OK. Also, a bad battery typically results in Starting and/or Idle issues which i am Not having. that being said, im not completely rulling it out yet. -thanks
 
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Dom426h

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another thought. If this is a faulty sensor or sensor connection i would like to Eliminate a few and focus on the likely ones. Tomorrow im planning on starting her up and going around the engine with my buddy and jiggling every electrical connection & sensor that we can reach in hope of Triggering the problem.

as i said befor, when the problem occures i can push the clutch in and rev her all the way up. This tells me that the TPS Throttle Position Sensor is working ok., Make sense?
(i will be checking the voltage to see if it is within spec range as a doublecheck)
Im also thinking No on the O2sensors since my very intermittent symptoms dont seem to line up (but i will check the voltage and speed of switching when i plug in a scanner to doublecheck)
 

dave6666

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another thought. If this is a faulty sensor or sensor connection i would like to Eliminate a few and focus on the likely ones. Tomorrow im planning on starting her up and going around the engine with my buddy and jiggling every electrical connection & sensor that we can reach in hope of Triggering the problem.

as i said befor, when the problem occures i can push the clutch in and rev her all the way up. This tells me that the TPS Throttle Position Sensor is working ok., Make sense?
(i will be checking the voltage to see if it is within spec range as a doublecheck)
Im also thinking No on the O2sensors since my very intermittent symptoms dont seem to line up (but i will check the voltage and speed of switching when i plug in a scanner to doublecheck)


On the other hand which sensors have moving parts? Things that can go kinda bad, sometimes bad, but not always bad?

Cam and crank sensors - Probably hall effect and no moving sliding parts.

IAT - Thermistor? No moving parts if so.

MAP sensor - Diaphragm to stress cell or other resistive device? Maybe moving parts.

TPS sensor - Sliding resistive device.

IAC - Moving parts... Yup.

Coolant thermostat - Thermistors

How about a faulty injector or injector connection? Or would that throw a code for sure?
 
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Dom426h

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IAC? nope. i dont have an idle problem. when the prob happens i am at part throttle. Besides, once those butterflies are cracked even only say 10% i doubt the cylinders even care if that IAC has a potato in it:omg:.

No to the faulty injector connection. If one injector was malfunctioning it would feel like i was running on 9cly, but thats not it. i feel like im running on Nothing (like fuel or spark is being intermittently Cut)
 

Tom F&L GoR

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What does the tachometer do during these episodes?

This may have been said, but ensuring grounds, and perhaps not just one being enough.

(Funny story - early in my Texaco days we worked on a multi-fuel engine with a high amp alternating current ignition system. Set one up at a customer lab with their "normal" ground strap and it would hardly run. Install the 3X battery cable size ground and it ran fine. On-off-on with the ground and you could make it run well-poor-well. That ignition system was dangerous to human tissue.)
 

hemibeep

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I had some strange issues.
1. had wiring rub on a screw below ECU, took 8 months to find. (did see trouble codes)
2. Bad gas cap. Not sure what this casues but it was an issue.
3. MY VOTE, replace battery. Big mess for mopars if they have any issues. Had issues with viper with two year old battery, and truck with three year old battery. Any time car acts up, replace battery. try to do this while battery under warranty.....
 

RTTTTed

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Other than mine idles sh_ty when the running crappy happens, sounds like my problem. Bad connection on power and IAT connectors to Vec.

When it starts running crappy, the a/f mix goes too fat (avg 13.4) and at tip in the egine goes lean (15.5 to 18) and stumbles or hesitates then runs fine until I lift my foot and start cruise again.

Damn speed limits ... it runs great with even slight throttle so if it was OK then I could cruise and 145mph my car would probably run perfect at that speed.

Oh well, I'' go play with my connectors again.

Ted
 

Qualitywires.com

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It's not uncommon for the crank sensors/ Cam sensors to go bad on these cars. Very simple install. Cam sensor is on the front and the crank is on the side of the oil filter if I am not mistaken. They can get gummed up with metal particals on the magnetic pick up after time. Had this happen when I had my GTS and also happened on a few Lamborghinis I worked on. I don't think the parts are expensive for the Viper. Also it might have been mentioned before, but I would look at the connections (wires to the TPS) to make sure they are okay. From memory, I think they go in the harness/connector horizontal. Think of a paper clip bending after awhile, it will break. We all know the Viper engine doesn't idle smoothly and there's allot of shaking going on in the engine bay. Hope this helps.
 
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Dom426h

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thanks ab, cam position sensor has been up there on my radar. BUT, i recently had one go bad on my dodgeDakota. When it went bad i didnt notice the engine running any differently. The check engine light came on and went into limp-mode. but the truck ran fine for a few days untill i replaced it and cleared the code.

Now what are the chances of the sensor going bad (NOTICABLY bad, multiple times for more then a few minuts and Not throwing a code?

You've got me thinking though about:
They can get gummed up with metal particals on the magnetic pick up after time.

If this is True then the sensor would still be 100%functional but just blocked giving the wrong signal.
This might Not trip a CEL because the sensor is still opperatign within its voltage spec.

Now Get This: I am DUE for an oil change, 5,000K on the Dot. Is it possible that simply changing my oil will clean up a dirty CAM/CRANK sensor?

STAY TUNED!:eater:
 

Tom F&L GoR

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No. Engine oil doesn't have anti-magnetism additives. If you suspect metal on the sensor but the sensor is working, just unscrew it, wipe it off and put it back in.
 
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Dom426h

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hmmm, on second thought i think i might just be getting my hopes up. With that notch on the camshaft spinning very fast & close to the sensor i'd think it would be pretty difficult for anything to accumulate on it. Then again i have no idea just how magnetic it is when On...
 

Ratical2

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One variable that you haven't mentioned is temperature. What are the ambient temps when you have a problem? Is it more likely to act up when the temps are higher?
As things heat up they expand. If a wire is broken it can stay connected at lower temps but separate at higher temps. This could happen with a wire or connector or a sensor.
In a former job I would keep a can of freeze it handy to diagnose intermittent problems with electronic gear.
 
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Dom426h

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Radical,
Heat? that did cross my mind. But Nope. It has only happend when im cruzing along at 190deg. Never when hotter with stop/go. Also, if i shut er down for a couple min then start back up with heatsoak, still no prob.

Tom,
yea but since the prob only happens every 200miles or so, switching parts one at a time with someone would be a lengthy process...
also, with reguards to the oil, i Wasnt suggesting that oil would would do Anything magnetical to clean the sensor. I was thinking that when the sensor is ON, my worn old oil is magneticaly sticking to it blocking the signal. When OFF the oild flows and dripps off which might explain why when the prob happens if i shut down and let sit for awhile she starts back up fine. So if this Theory is true, then switching to ANY fresh oil would clear it up.
get it?
 

dave6666

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Like did I stay at a Holiday Inn Express last night kind of get it? :dunno:



Really though, if I was troubleshooting an intermittent gremlin like that, I would start systematically replacing sensors and sending units. Whether they appear to be working, broken or not. A process of elimination that on a 10 year old car is not that silly of a means to do troubleshooting.

Beats the heck out of waiting for my next smartass reply doesn't it? :rolaugh:
 

Rock Morgan

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I had a 97 GTS what felt the same way. We chased it with a lot of expensive parts like sensors, throttle body, plugs, and wires. Just before throwing our hands up we decided to go ahead and replaced the perfectly good old battery we had tested. Problem solved.
 

Tom F&L GoR

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Tom,
yea but since the prob only happens every 200miles or so, switching parts one at a time with someone would be a lengthy process...

Plan B would be to switch all of them and see where the problem goes. If the problem moves, at least then you can celebrate the fact it is a sensor and not a loose wire "somewhere."

The other option is to leave more gauges and measuring devices on it so when it happens in the next 200 miles you have the diagnostic tools already there.

When OFF the oild flows and dripps off which might explain why when the prob happens if i shut down and let sit for awhile she starts back up fine. So if this Theory is true, then switching to ANY fresh oil would clear it up.
get it?

I get it, but I'd have to stay at the Holiday Inn another night. If this Theory is true, you could swish a magnet in the pan of collected used oil and it would come out fuzzy. You don't want that to be true.
 

Tom F&L GoR

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I had a 97 GTS what felt the same way. We chased it with a lot of expensive parts like sensors, throttle body, plugs, and wires. Just before throwing our hands up we decided to go ahead and replaced the perfectly good old battery we had tested. Problem solved.

I have had two batteries just suddenly go dead. Apparently the plates inside get loose, make contact and you go from 12V to 6V and that is it. Somewhat age unrelated, too, although not exactly brand new.

I'm repeating Rock's message because while in older cars you could even remove the battery while the car was running (let alternator power the system) in a newer car I don't think you can get away with this. You really need that good buddy...

BTW, does the tachometer work while you have the problem?
 

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