'89 BII 2.9 problems

[97fordrunner]

Hey all

My '89 BII is having issues again. I can't seem to clear the codes from the computer. I have tried the method of getting the codes flashing and then disconecting the jumper wire, Or disconnecting the battery overnight and also tried hooking up my works Snap-on Modis computer to it but with that one when its running or not it won't clear codes or run tests it just says battery voltage to low and that is with a charger hooked up to it as well, I am lost and am not sure whats next. My boss is convinced the computer is fried but I don't want to throw money towards that unless i'm sure.

Thanks all

Jon

 

[adsm08]

Whats the code?

 

[97fordrunner]

There is all sorts of them, I got fed up on night and while it was running started unplugging things to see if it changed the idle. Thats why I wanna clear them to see if anything new pops up

 

[97fordrunner]

Update: Fuel Psi is good, I also put the vac gauge on it and at idle it runs at only 9 then it climbs a bit when revved up and once it goes back to idle it hangs around 10-12. Timing looks good with the spout disconnected still can't get rid of the codes stored though!

 

[bronco_lou]

Update: Fuel Psi is good, I also put the vac gauge on it and at idle it runs at only 9 then it climbs a bit when revved up and once it goes back to idle it hangs around 10-12. Timing looks good with the spout disconnected still can't get rid of the codes stored though!

what are the codes that it is flashing?
Louis

 

[adsm08]

If you are getting enough unrelated codes I'd guess the PCM has a problem, but I'd still like to know what they all are before I say condem the PCM.

 

[97fordrunner]

I'll see what its throwing again today.

 

[Bent Bolt]

I'll see what its throwing again today.

And the symptoms that you're having as well.

 

[97fordrunner]

OK here are the codes that are in the computer.

22-MAP sensor which is brand new but I unplugged it once to check RPM change.
51-ECT haven't touched that so probably get a new one in Monday.
53-TPS, I did unplug that to check RPM change as well
54-IAT don't think I messed with that one at all


The last three are Auto trans codes which are being thrown cause I swapped in the M5OD.
67-Park/Neutral fault
89- Converter Clutch Overide Solenoid
86-3/4 shift solenoid

As far as what it is doing, It usually starts easy and runs good for a sec or two then the idle goes way down and it has a bad miss and is running really rich, like raw fuel coming out the tail pipe. FPR looks ok no fuel in the vac line or anything, fuel PSI is in the normal range, Plugs,Wires,TFI, Cap & Rotor are newer. A few weeks ago I was able to drive it around for quite awhile, it wasn't running perfect but it at least could accelerate without backfiring and poping. I have gone thru the wireing and havn't found anything on the engine harness bad, I have cleaned all he grounds. No Vac leaks that I can find anywhere. VAC gauge on it only pulled around 8-10 until revved then back at idle it ran in the 10-12 range but was steady.

 

[eclipse2001gt]

Do you have a exhaust leak up by the engine? the headers that is.

 

[Spitfire1975]

That's pretty low vacuum from I understand. Should hold steady between ~19-22 in. Not saying it is the cause of your problems, but also not necessarily good.

 

[97fordrunner]

there is a minor exhaust leak in the drivers side manifold. Low Vacuum=Low Compression?

 

[kimcrwbr1]

You probably have done so but go through and check all your wires and connectors pull the connectors apart to inspect and put them back together with dielectric grease and make sure all the pins are all the way in. check all the vacuum lines for cracks TB and EGR gaskets and intake manifold bolts are tite. The vacuum is way low hence the map code once the wires and vacuum issue is addressed and you fix the codes as they come up lower numbers first then erase the memory first the disconnect the batt for 1/2 hour. Then you need to run the engine at medium speeds until the engine reaches operating temp and run the codes hot. There is probably nothing wrong with the computer first lose the map code then address the next in line one at a time one sensor can throw multiple codes and always reset the computer whenever you change or clean a sensor to set the new values.

 

[adsm08]

Spitfire is right, that is kind low for vacuum, and since you have a vacuum driven pressure regulator low vacuum will simulate a higher than actual throttle position, thus causing it to dump fuel.

Low vacuum doesn't always mean low compression, but that is one possible cause. I would suspect intake gaskets, bad vac lines, or even a bad brake booster before I tear into the engine. A compression test isn't out of order at this point however.

I'm also interested in your two temperature sensors that are out of range. I don't have diagram handy, but I think those two sensor share a ground somewhere. But then again on an 89 it could just be two bad sensors.

 

[kimcrwbr1]

Put your hand over the TB when it is running and see if the vacuum reading goes up will tell you if you have a vacuum leak somewhere the best way I have found to find a leak is tape a soft piece of wire to the end of a vacuum hose about three feet long leaving the end of the hose open. Stick the hose up to your ear and search around all the gaskets and hoses listening for leaks you will hear a hissing noise when you get close and can bend the wire to reach tite places but I am guessing either throttle body or egr gasket loose or needs replaced and yea the brake booster can have a internal leak push on the brake and see if the engine reacts or pull and plug the vac to it. If the compression is even focus on the intake in the tech library it tells you how to read the vacuum guage scroll down close to the bottom. It says 17-21 at an idle but the 2.9 should be at least 19 if the valves and rings are good.