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Discussion Starter · #1 ·
Hey there fellas my name is Steve, I’m brand new to the site and still fairly new to the Ownership of my Gen 1 Roadster.... my car is a 94’ RT/10 Roadster with a little over 50K Miles. the only bolt on thing I’ve done was install a duel CAI so far. Upon my purchase as I started to drive her more often to familiarize myself with the car.... she Sounded nice, ran out nice then started to go into limp mode or simply shutting off. Didn’t matter what gear, RPM, or speed but mostly seemed to do it after getting warmer or hard acceleration... this sometimes comes with some sputtering and backfire before or as it shuts off... I could restart and it would drive fine for a bit then same thing happens, for starters I jumped on a few random forums and listened in on some very similar issues other guys were trying to figure out.... so with what I read I started in this order replacing basic parts and sensors... first I replaced the battery then both downstream O2 sensors, no luck.... then was pulling a code 14 map sensors voltage to high/low, so replaced the map sensor no luck... found some areas of wear in the oem air intake baffle tube and discovered the Hood was pushing the tube down onto the drive pulleys/belt. Belt and pullys undamaged, so I ordered the aftermarket duel intake setup and installed. I fixed the rubbing on the pully but issue still there... I then replaced all plugs with NGK plugs, and No 4 NGK Silicon wires... note: plugs I pulled out were highly covered in carbon and just plain ugly for the majority of them at least... took off the air intake tubes and did the throttle body cleaning procedures and sprayed about a half can of throttle body cleaner through both TB’s also replaced the PCV valve. THEN It ran awesome with the acception of a rough or irratic idle not rite away but mostly once the car warmed up. Still ran great! No more shutting off or backfires or even sounding like it wants to turn off. I took it on a few road trips and drove her for a couple more months without any issues. Put her to bed for the winter and didn’t think about putting a battery charger or tender on the battery as it sat for a few months. Went to fire her up one day and the battery was dead. So I got the battery tested and it was telling auto parts store it was still good. So I recharged it up got it to hold a consistent charge and installed it... drove it about a half dozen times without issue... then one day I was navigating through a roundabout and when I went to apply the throttle it was air... it had turned off on me for the 1st time since the previous summer. Upon reading more posts on these cars I saw a guy had identical issues with a 93’ so same generation as what I have. His solution was to replace both the camshaft positioning and crankshaft positioning sensors. I checked to see what codes It was throwing by using the ignition on off cycle since I don’t have an obd1 scanner and nobody local shop wise has this type of plug to get a scan done with the acception of my local Dodge dealership and the wait is rediculously long and they want a ton of money just to run a scan. So the ignition cycle kicks out 12, and 14 codes, I believe the 12 code is battery or power related and figured it might have triggered the 14 map code again... so at $200 each I decided to start with the crankshaft positioning sensor and swapped out with a new one. I’m not sure if the relearn process is correct of approximately 4-6 cold to warm start up and drive with the A/C or defrost unit turned on to relearn the pcm with the replaced parts? So I disconnected the positive battery cable and let sit for an hour or so to clear stored codes.... I drove the car upon replacing the crankshaft positioning sensor and it did it again, but as it dies briefly shows the battery icon followed by the engine light.... upon trying to restart it acts like it doesn’t wanna stay on and shuts off immediately. So I disconnected the battery positive cable to clear out again and drove it and after it warmed up around 190• it did it again only throwing the 12 code this time without the 14 code... am I not clearing out my PCM properly or running the relearn process correctly??? Should I mess with replacing the camshaft positioning sensor?? Or that along with the Throttle body positioning sensors?? Or could this be Alternator malfunction or maybe the battery running voltage is simply too low now after it drained down and I recharged it?? Maybe someone could give me a better or more accurate direction or steps to locate this annoying gremlin in my ride?? I love this car and really wanna figure it out as I feel like I’ve had it over a year and still have yet to really enjoy it... I have lots of visual ideas and personal ideas to make the car more my style and looks on the interior and outside body but can’t seem to get it running the way it should be! If anyone out there had issues early on in owning one of these earlier years of vipers then I know you feel me! Any suggestions or experienced ideas would be more than appreciated! Thanks for reading my message I look forward to reading what you guys think! Thanks again...

Steve from Burbank, Wa....
 

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ASD or perhaps fuel pump. RT's require a jigsaw to cut an access hole in the trunk closeout panel for pump access.

'92-95 were OBD-I. I think the Gen 1s used blinky-codes on the message center for diagnostic trouble codes. Early Gen 2s did as well.

Procedure: Key in ... on/off, on/off, on/off, on. Have a piece of paper and pencil handy to write the number of red blinks for first and second digits of stored codes. Codes will increment lowest to highest. I think when it's done you will get either 5 or 6 flashes indicating end of data. It doesn't hurt to do it twice to make sure you got them all.

You may also have cats coming apart and randomly obstructing the exhaust.
 
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Discussion Starter · #6 ·
I have already pulled the code and it gives me a 12 each time and the Diagnostic code book says these are all 4 digit codes so it it telling me that it’s a 0012 or 1200??? Or even 0120?
 

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Your car is OBD1 and therefore not a 4 digit code but a 2 digit. Code 12 retrieved by cycling the key means the battery was disconnected within the last 50 key cycles. As Dean stated code 55 is "end of message". There should be a dedicated diagnostic port somewhere under the hood as other Chrysler vehicles of that era and a dedicated scan tool will retrieve those codes and allow real time viewing of important data stream from sensors that include but not limited to the following: TPS, MAP, CTS, IAT, CRANK/CAM, VSS, IAC.
 

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Kitty Wrangler Denali Owner
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I have already pulled the code and it gives me a 12 each time..?
More pieces to the puzzle!

Everything I find on code 12:

"This code shows up when power to the computer has been interrupted as when the computer has been reset by disconnecting the battery"

"Direct Battery input to PCM disconnected within last 50 ignition key-on cycles. Normal if battery has been disconnected, otherwise check battery power and ground connections."

"Computer lost power recently. Nothing to worry about if you disconnected your battery for some reason."


"Battery or power line recently disconnected - This code is normal if the electrical system has been worked on or the battery has recently been disconnected. It will be removed after 50 ignition switch on/off cycles."

"Low system voltage, bad battery or battery terminals - If the system recently had a power drop (due to a dead battery or bad alternator), this code will appear. If the battery terminals are bad and the engine was jumped, this code will appear."

"Bad connection or wiring - Check the wiring and connections between the battery, power module, and logic module (or SMEC). Check all fusible links and power connectors to the battery. Clean and regrease any corroded connectors with dielectric grease and repair any shorts"

So, I'd start with your battery and work your way to the PDC. Good luck man.

Also, don't forget your original post said:

Or could this be Alternator malfunction or maybe the battery running voltage is simply too low now after it drained down and I recharged it??
Maybe you already figured it.
 

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Discussion Starter · #9 ·
Okay so the battery I had was still good but weak, so they swapped me out with a brand new battery it wasn’t currently throwing any codes other than the 50 key cycle disconnect (12) code. Got a brand new camshaft position sensor that came with an updated version of pigtail for the plug and I spliced the 3 wires together perfectly, properly marked the space required for the sensor face to the face of the cam gear inside the timing case on the (high step) part of the gear as it calls for. Ended up having to shave off the red plastic in the positive end of my battery wire because the collar on ring connecter that the battery maintainer or trickle charger has it too thick to tighten down almost stripped out the threads on the positive side because of it. So I’m not sure how Important that red molding is around the end of the positive wire but it allowed me to install the positive side of the battery tender plug but maybe it’s loosing power without having the red cap over it and shaving it off?? Or would I be better off installing the battery tender plug up in the engine bay where it’s jump started from?? After I tried to start the relearn process on the 1st cold to hot start and run it sputtered the 1st roundabout I throttled down to take the got on freeway and it ran great for the next 12 miles or so... parked it for about an hour did another drive cycle the same distance, no issues... today I took it to work about another 12 miles and it never sputtered once or shut off... of course it’s cooler in the AM... lunch time I took it for another cycle for about 6 miles round trip to the store and back to work no issues... after work I ran errands in town drove about 10-15 miles and went to slow down for a red light and It turned off on me.... stated up light turned green and it tried sputtering a bit then ran fine again??? It’s something simple i know it... because it runs great when not doing this shit.. what’s the best scanner for these cars and are they accurate and affordable?? Probably have to order online somewhere anyone have any direction on that? Damn this is really starting to discourage me from keeping my car but I wanna fix it and understand what exactly is happening. Not a lot of people who are local will know anything about this thing and most especially the dealerships all run from it because of the rarity... seems like it does this mostly after it’s over 190 degrees so heat is triggering it maybe... I’m thinking about relocating the battery to the low left or drivers side inside the truck compartment, should be able to reach with original battery wires just need to secure it down and get a longer negitive wire and might be better placement but idk if it’ll depreciate it’s value for that kinda modification or not if anyone has any input on that idea I’m all ears... thanks for everyone who has chimed in on my post so far it’s greatly appreciated and you’re time in doing so is very appreciated so keep any other ideas or comments coming... I’m a sponge and I’m learning more everyday.
 

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Gawd damn it's hard to read your posts! Do you know about the <Enter> key on your keyboard? Do you know about things called paragraphs?

Your battery is SUPPOSED TO BE ON THE LEFT behind the tire. If it's in the middle of the trunk floor under a cover, then you have a '92 or '93. Do you have a coolant tank on the passenger front fender liner? The battery bracket has a round plastic puck on the backside with a wire connected to it. It is a temperature sensor and it is critical for proper PCM operation.

Most people put the battery tender wires under the hood near the door hinge covers.

It almost sounds like you have bad ground(s) somewhere and these cars are very sensitive to that.
 

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Kitty Wrangler Denali Owner
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It almost sounds like you have bad ground(s) somewhere and these cars are very sensitive to that.
This has been suggested/alluded to enough times in this thread, should've already been done.

Feels like it's the same questions over and over without checking out the battery to PDC connection integrity already. For example, the +/- cables coming off the battery.

C'mon Op, let's go.
 

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That's quite alright. Brevity is your friend.
 
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