crazy codes, mystery wire 89 318 changes by hour
 

here is history. 1989 dodge b250 318. severe foaming radiator and water in oil. engine ran fine idled an drove great (overheating, and obvious oil/water issues aside) broke down and decided to do the work. replaced head gaskets, intake, exhaust etc. during re assembly i broke a mystery wire and also hooked up the map sensor to the TPS and vice versa. when i finally figured that one out with the help of another poster engine started up and seemed to run but would not idle especially under load (in gear) finally found broken vacuum hose to some kind of crazy looking wire bunch on pass side valve cover. when i put the hose back on engine idled much smoother and seemed to idle no problem in gear. BTW the map sensor wire has been cut and bypassed. so now that i was at this point (things appearing to work) i only got a 12(battery) 13(map sensor) and 55(end) for codes. today when i went to start it and move it out of the garage the engine started right up but idled rough. did run in gear and was able to move it but it sounded like it was running on 4 cyl. so what the heck? checked the codes and in this order 12,26,13,27,55. strange order. but now i am getting fuel injector codes that weren't there yesterday and i did nothing to the vehicle. now while it sounds rough like i said it does idle and does idle in gear and did move the vehicle. now to the mystery wire. on the TBI there is a 4 wire plug that goes to the injectors. on the second wire from the top (tan) someone spliced into this wire and ran it across the engine up under the dash. now i never looked to see where it went and during the dissassembly and somewhere along the line it got disconnected. so one time i start it and it doesnt idle or handle a load and when i do start it it idles up fast and takes a while to settle, the next time i start it i get the vacuum hose spliced and things seem to be fine (only one code) and then the next time 3 codes and it runs terrible. no electrical components were replaced or changed during this repair and vehicle did run and idle very well prior to beginning the repair

While I also have an '89, same engine and such, I can only guess that your mysto wire was the previous owners attempt to add a antitheft fuel cutoff switch.

Those three solenoids on the pass side valve cover are for the EGR valve, cannister purge, and one other whose purpose I forget. Make sure the pintle moves up and down(EGR) with the throttle with a slight delay. If it doesn't move, take it off and clean it, and try to loosen it up.

Rough idling or a 4 cylinder feeling might be caused by an egr valve which is stuck open. Or you messed up the wiring order, or your distributor or wires are toast.

You post is very difficult to read without there being any paragraphs.

There is also the possibility your catalytic converter is plugged, depending on how long you drove it with blown head gaskets.

i believe firing order is correct as it did run fine for a while as stated and nothing changed.

it was mentioned to me that the mystery wire was part of an alarm or other such thing from the previous owner, i only bring it up as it goes to a "fuel delivery" wire and it seems i am having a "fuel delivery" problem.

i only drove the engine for a very short period of time (20 miles) when the gaskets were blown. and i am still not sure that was what caused the problem as the gaskets i took off looked okay, but that is another story and i think that would eliminate the cat. onv. plugging.

as i indicated above. when the hose to the three solenoids was disconnected the engine did start but idled high for a minute and slowly settled down. the engine would stall when i put it into gear. if memory served the codes were 12,13,24,42,55. when i hooked up the hose the engine idle slowed down and would idle even in gear. i checked the codes and had 12,13,55.

the next morning(today) without changing anything i started engine and very quickly noticed that the sound of the engine was different and seemed to "sound" like it was idling rough. i put the vehicle in gear and had backed up and pulled it forward and the engine would idle even in gear but i could tell something was wrong. so i checked the codes. and as stated above got the strange order and different codes than before. i checked the codes twice.

i know parts can break at any time but the cap and rotor are very new (less than 500 miles) wires are less than 2000 miles.

when i had the engine apart, i did not remove the dist, but did remove the cap and wires. (my firing order and #1 position does not match the manual) that took a while to figure out. if some dirt or debris fell down in the dist(doubtful) would this cause the injectors to act up or for me to get the injector codes?

12 battery disconnect,13 and 24 are map sensor codes,27 is a injector code, and 55 is end of test.

master tech, i am aware of the codes thanks to someone posting a link to all the codes in a previous thread. what my question is why are they changing, and what would cause me to have the 26,27 all of a sudden.

does someone know a way to trouble shoot that code or does someone know what electrical problem may exist that would cause the injectors to act up intermittantly?

Maybe shorted wires or bad contact at the injectors, or even the PCM drivers. Could also be the injectors themselfs.

did not pull injectors or caps during the work so limited chance they could get damaged or bad contact. dont know what pcm driver is. it if were to be a shorted wire any guess as to where to start? when i went out to begin working on van today, engine started up and ran rough for a little while, i put it on the street to run it under a load and somewhere along the line it started running better. idle slowed down, started right up etc. pulled back in garage, started to deal with newly discovered water leak, went to start engine back up. very difficult to start, finally started high idle.

swapped out TPS still same problem finally did get it started at one point and idle slowed down until it finally just stalled. now wont crank.

The PCM drivers are within the engine computer, meaning the ECM/PCM/smec could be bad, and that is my best guess as to what is going on with yours.

When my ECM was failing, I was getting an occasional relay clicking, stuttering stumbling and backfiring through the TB, that after 30 to 45 seconds would smooth out and be normal.

Keep in mind Cardone( a major brand of ECM rebuilders) says they rarely fail on their own, something causes them to Fail.

Mine failed because one wire leading to a solenoid in the transmission was grounding out on the trannies bell housing.

I believe the light blue wire with the black stripe feeds 5 volts to both the Map and TPS sensors. That other mysto wire going from your injectors and dissappearing under your dash must be figured out. We cannot do that for you. It is not stock.

When my ECM was beginning to fail, When I would disconnect the battery for a while, then restart, it would eliminate the 30 to 45 seconds of stumbling and backfiring, for a few weeks anyway, before I finally found the grounded tranny wire, then replaced the ECM.

Good luck, over and out.

yes agree the mysto wire is not stock and several people have suggested some type of alarm from previous owner. i am attempting to test the TPS ( i have 2 of them) they read 200 ohms in idle position but when i turn up throttle they go to dead short. am i testing them wrong?

new thing i noticed with the running after repairs is severe black soot on plugs. they are not wet oily but dry black - never had this before.

i agree with you that ECM need to go bad for a reason. that is why i am so hesitant to stray to far from the basics. some of my problems stem from not knowing where/what things are. example was told to test resistance between ecm harness and injector connector driver just have no idea where the ecm harness is.

and checked the codes again as they seem to change every time i crank the engine. the fuel injector codes are gone now have battery 12, map 13 map 13, TPS 24, and end. when your ECM was failing did it constantly give you different codes?

When my ecm was failing I was getting a couple codes, one was the map sensor, But one would expect that to light with the engine stuttering stumbling and backfiring. The other that kept coming up was the battery temp sensor code. I forget which number that is. There were occasionally some others, I forget.

Your ECm lis located on the firewall, up top nearer the passenger side.

It has 2 connectors. A 14 pin connector, and a 60 pin connector.

I have had issues with my 14 pin connector, and jury rigged some connections by drilling through the connector and inserting the stripped wire through it and bending it back upon the pin recepticles.

The 60 pin connector or the 14, if wet can cause all sorts of zany issues.

This link tells you what all the pins are for.
http://minimopar.knizefamily.net/ecu/sbec-1990-tbi.html
A little searching on that site will also yield a pin readout for the 14 pin connector.

You should get a haynes or chilton manual or better yet a factory service manual from e bay.. They have procedures for testing the sensors.