[plumkrzy3]

So my 91 Turbo car has been sitting for a couple months, but needed it as another one the POS's died. Get in, fires right up, runs for a minute, maybe, the check engine light comes on and it starts to run like crap, missing and engine speed slows down enough to kill it.

Check the codes:

13- MAP sensor or vacuum line may not be working
Easy enough, check the vacuum hose and maybe replace the MAP

27- (turbo) injector circuit #2 not switching right
Don't have a clue on this one and more than likely the cause of the running issue.

Any ideas?

 

[Bob Lincoln]

Check the vacuum lines, especially to the MAP, for cracking. Check the engine grounds at the firewall-to-manifold braided strap, and the ring tongue terminal to the block on the driver's side rear corner. It's also possible that there is condensation in the vacuum line.

Check also for rodent nesting and nibbling of electrical and vacuum lines.

 

[ChargedDust]

Also check the Baro solenoid, the line to the MAP runs through the BARO first. You can remove that solenoid and shoot a little WD-40 in it and use some jumper wire to cycle it a bunch of times, then a some air to blast out any remaining WD-40 so it doesn't foul the MAP sensor.

I would pull the whole injector wiring sub-harness and clean all the terminals, both at the injector connection point and where it plugs into the main harness. Cut some small strips of fine sandpaper and fold the over enough so that they're big enough to sand the terminals on both sides, then give the terminals a little tweak bend close so that they make good contact on the injector pins. Also use the sandpaper to clean the injector pins. And having the harness out gives you a chance to properly inspect it for melting wires, broken wires, shorts ect.

 

[ImperialCrown]

A simple stall can set a MAP vacuum (13) code because of the sudden loss of vacuum upon a stall while the TPS would disagree with that happening.
Loss of the #2 cylinder fuel injector power or ground (module) side is probably the root cause. It is rarely the injector itself. Any connector corrosion or wire chewing going on?

 

[plumkrzy3]

Standing in front of the car, looking at the engine compartment, is the MAP and Baro on the pass side of the firewall, just above where the a/c expansion valve is?

I did disconnect the injector harness at the main plug in, just to see if it was all corroded, didn't look bad, but need to check into it further. Do the plug ins just pull off each injector or is there a clip or something? The engine was hot when I was looking at it last night, so I didn't dig into it too much.

 

[ImperialCrown]

There should be a steel retainer clip on the injector connector. You can spread it to release it:
injector-plug-harness-2-500.jpg

Also there may be the intermediate harness and the SBEC connector to look at. Heat will cook wire insulation:

LQNIp.jpg

SBEC_60.jpg

8y5ds2.jpg