View Full Version : Which scanner?

09-13-2007, 12:10 PM
What scanner will work for a 92 Spirit r/t?

I've got a intermittent miss that causes the check engine light to come on.

A large jerky miss, about one every couple of seconds. (check engine light)
Irratic idle, it can surge or stay around 2K for extended periods of time, or be normal.
My air/fuel (autometer) gage is bliping over to lean when I get a miss, otherwise it still swings around but at a significantly slower rate.
If I WOT it at any rpm range (1 to 2.5K, I have been staying fairly low since it is missing so badly) it doesn't miss and I am rich according to the gage. It is just barely building boost by the way.
When the A/C is on the misses are more frequent.

This car is stock asside from a grainger set to 14 psi.

I have two theories that contradict each other.
#1 Since the a/f gage hits lean for a second during the miss, that means an injector isn't firing. This causes the o2 sensor to read lean, and obviously a miss.
#2 AIS, o2, or some sensor is acting up. Since the miss never occurs at WOT (programmed fuel curve) one of the sensors, that lets the computer know what is going on, is giving some bad info.

Thoughts on my o2 sensor. It shouldn't be bad since I'm getting "correct" readings on my gage. However maybe it is bad since the normal wild swinging is now a relaxed wave.

I disconnected and cleaned the injector connections, but I didn't have any dielectric grease on hand. I have some now and plan to use it tomorrow, but just the cleaning didn't help. I figure it should have fixed it temporarily at least.

09-13-2007, 12:15 PM
You could have gunky injectors. Put some cleaner through it, or use my recipe, 2oz Isopropyl Alcohol (70% or better), 2oz kerosene or varsol, 1oz tranny fluid to a full tank.

09-13-2007, 10:24 PM
I have an OTC 4000E that I use with my '91 Spirit R/T and it works great. Works great on my other two cars too. It uses the '93 Pathfinder II cartridge. I know the '92 SBEC is a little bit different though.

I would check for intermittent connection within the fuel injector subharness and 6-pin connector. Move it around with the car running and see if it freaks out. Probably set a code 27 if so.

09-13-2007, 10:28 PM
have you pulled the plugs and looked at them? how old are your wires? maybe your just due for a tune up. fuel filter?

just sayn start with the basics. all the scanner is gonna tell you is that its mis-firing. sure you can read o2, iac, and the rest but my money is on the basics.

good luch

09-14-2007, 12:29 AM
Check for vac. leaks, fuel pres. clogged ex. etc. Check this site out for good info:http://www.aicautosite.com/garage/garmenu.asp:thumb:

09-14-2007, 07:32 AM
Check the 02 sensor wiring. It essentially goes over top of the exhaust manifold and over time it gets fried and causes goofy driveability issues. Check that first and confirm it isn't the problem. Then go from there. Ruling out vacuum leaks is a good second step.

I have an OTC scanner 2000. Bought it off ebay real cheap. Works good. Scanners only as good as the info going into it. A scanner won't tell you a mechanical problem like vac leak or fried 02 sensor wires :-)

09-14-2007, 12:14 PM
Have you tried checking the keyon/off codes? If it's tripping the check engine light, it should have something stored. Half the time it seems like it's more of a clue than a cause, but still worth checking if you haven't already.

09-18-2007, 12:32 PM
I had another car giving me some trouble so I didn't get to do much, but....

I removed, inspected, cleaned, and greased the injector harness on both ends.

I have run two prestone injector cleaner bottles though it. The first was very concentrated.

The o2 wires are kept well away from the exhaust.

I did get ALOT of codes. I forgot the list at home, and I'm at work right now. It may be easier to list the ones I didn't get.

I havn't checked the plugs yet. I ran out of time. I will check them tonight though. I ordered an o2 sensor from ebay. I figure it can't hurt, and is reasonably cheep. It has big Magnacore wires that should be OK, but I may try to replace them, and see what that does. I can always return the new ones. I will also replace the fuel filter.

I forgot to mention. My VSS is acting up too. These are both intermittent problems and often occur independently from each other. So, sometimes it will run well without the speedometer working, and sometimes it will run bad with the speedo working. I have to check and maybe clean the wiring here, but I don't think this is causing my drivability problem.

This sucks, and I even had a chance to make a run at a lamborgini Mercialago (spelling?) the other day. He was getting on the highway a few cars ahead of me, and got on it hard once he got to the fast lane. By the time I limped up to speed (it won't miss when I'm being very gentle) and caught another glimpse of him he was an easy 1/8 ahead and moving very fast.

09-18-2007, 12:59 PM
Speed sensor failure can cause idle issues. Are you running a stock blow off valve?

09-18-2007, 01:50 PM
Yes I do have a stock BOV.

Will a VSS be bad but still give me the "correct" speed? Can it tell the speedo the correct speed, but be giving the computer faulty info?

I thought since I had the speedo working with a poor running engine, and vica verca, that the vss wasn't the culpret. If the speedo drops to zero while cruizing, which it will, and then the engine acts up, then I would say yes the VSS is my problem.

09-18-2007, 01:53 PM
VSS shouldn't cause issues while driving around, except when you stop at a light it may stall. Does your speedo jump around? It sounds like an intermittent connection to me. I recently had what I thought was a VSS failure, but it turned out one of the big connectors behind the battery that containted the VSS circuit (white/orange) was messed up and the circuit was open from there on. I crimped the pin so it had a more postive contact and it works again.

09-18-2007, 02:06 PM
When I've had the VSS die, the speedo will stop working. It may work intermittently, but a bad speed sensor can cause issues.

I don't think that is your only problem. If you have the stock BOV they are prone to rupturing and you can lose boost that way. Have you gone over your vacuum lines?

09-18-2007, 02:08 PM
My speedo either moves normally, or is at zero. It idles at 1500 to 2000 rpms when the miss, check engine light starts to act up. Sometimes it will surge, sometimes it won't.

Theres another possibility. I havn't messed with the computers connections, or the ones in that general area.

09-18-2007, 02:48 PM
Another thing you should do is check all the grounds and make sure they are clean. I had one under the battery tray of my R/T cause some issues years ago.

09-20-2007, 12:22 PM
The car had a good day yesterday, and didn't act up at all. Today is back to the same. Spark plugs are good. Grounds are good, I even have an extra. I forgot my code list again.

This isn't a vacuum/intake leak. The high idle and miss are an electrical/fuel issue. When it is inbetween misses it sounds, pulls, and runs normal. The misses have no pattern, and are very harsh, possibly multiple in sequence misses. The idle can change at any time. Ex.. Sitting at a light goes from 3-5 seconds of 1500 rpm, to 10 seconds of 2000 rpm, to regular idle until I go. The changes are instant.

While I decelerate in high gear (exit ramp), what would be a miss while in power turns into what I will call a change in effective compression. I go from having the 8.5:1 slowing me down to say 4.0:1, also in an instant. Thats just what it feels like, obviously not whats happening. The air/fuel gage swings up to rich too. Its normally pegged lean while decelerating. This is above the 2000 rpm idle that is currently the highest I've seen.

I know I'm talking alot without getting much done. I have an engine apart in my other car trying to solve a valvetrain problem. I had a cam get wipped smooth by some bad lifters. I am a glutton for punishment. The old cars I like are orphans, and the newer car I have is an oddball.

09-20-2007, 12:46 PM
I had a similar driveability issue years ago that ended up being the SMEC. That could be a possibility, but I'd try and rule out other things first.

09-20-2007, 02:02 PM
If you can find a basic OTC 4000E (or the usually more expensive 4000 Enhanced) it should work pretty well. The Pathfinder II cartridge works on domestic cars up to '93 and is most common. I've noticed a few issues with a few of the parameters not reading correctly on the '91 and/or '92-93 cars with some of the cartridges like the older pre-Pathfinder II ('93) carts and some of the newer ones like Pathfinder '96. If you want to do just basic checking of a few things and car find one the older OTC 2000 works pretty much the same and uses the same cartridges but has a smaller screen that you can't display as many parameters on at once. There's also software out there to data log using a computer attached to the scan tool so that isn't as big of a problem.

The factory DRB-II (Diagnostic Readout Box, second generation) used at the time the R/T's were new was made by OTC which is one of the main reasons I like using the 2000/4000 scanners. They are both somewhat similar in a few regards. If you can find one an actual DRB-II or a newer DRB-III would work great but are expensive. The DRB-II's seem to still be going for $300-500 range used and you could find a nice OTC 4000E or Enhanced for about half that. If you've used them before and are familiar with them some of the older Snap-On scan tools like the MT2500 with an older cartridge should also work well. I haven't used one on the R/T's but they've dropped in price on the used market in the last couple years where you might be able to pick one up if you keep your eyes open. I'd still probably pick an OTC though unless you have needs for something the Snap-On can do such as OBD-II, etc. The older OTC 2000 can't do that, the 4000E requires an add-on adapter, but you can do on the 4000 Enhanced or 4000 Elite if you have a '96+ cartridge for generic support and can do full manufacturer support on some cars up to '02 with the Deuce '02 cartridge which was the last update for that scanner family.

Eric H.

09-20-2007, 03:19 PM
Good info on the scanners and compatibility Eric, thanks!

I've got an OTC 2000 and it's served me well for a long time on my older mopars. Thinking of getting an OBDII complatible one eventually now that my "new" cars are no longer new...

10-16-2007, 03:36 PM
Its been a while, but I finally got it running good. Its been 3 days and hasn't returned so....

After piddling around here and there with connections. I just took every connection appart cleaned and put back together. I suspect one of the connections behind the battery. They had some crusty white lithium grease in there.

I found that "Deoxit" works pretty good for cleaning and protecting/greasing the old connectors. All I did was squirt a little carb cleaner in the end of the connector incase of any large amounts of grease/oil/whatever, squirt in the Deoxit stuff, work in it by dis/connecting a few times, reapply the Deoxit, and put them together for the final time. The amount of protection is yet to be determined. It is kinda oily, or greasy so it looks like it should do OK. It is very expensive for the quantity you get.