1987 TBI wontstay running, i did tune up and fuel filter already !!

[Rumble]

my truck is actually an 89 crew , so its square body, it ran decent when i bought it, not great, i finally got around to doing a tune up and still ran crappy, just did fuel filter, still wont stay running, it will start.

If i tap the gas constantly it will run rough, but no pedal and and steady pedal and it will die

I noticed a greeen wire on the passenger side of block near exhaust manifold, the tip was broken and dry rotted, looks like it connects to a sensor there, any idea what it is???????

thanx

[bloodybronco]

I have an 88 tbi wiring diagram, doesn't tell me where wires are but if you look at it i just copied the part with green wires on it
could be idle air control wires, tps, or map
hope this helps

[87 V20 Scottsdale]

Have you tried to see if it is throwing any trouble codes?

[Rumble]

no check engine light for the seconds that its running, a friend told me the green wire was coolant temp, he said connect or it would run rediculously rich,
i connected it but still runs like crap, i have to keep pumping the pedal to keep it idling
if there is no check engine light are there any trouble codes? how would i check them, my truck is too old for OBD 2 i think

[jchav62]

It's my understanding that TBI's need the coolant temp sensor to run right. I'm not sure if it's the green wire or not. I'd try repairing that connection and see if it helps.

[Rumble]

i connected that wire

[Rumble]

a mechanic friend of mine told me it was probably the distributor, he said very common problem,
i pulled a spark plug and had someone turn the motor over several times, it was dark out and i could barely see the spark, so we figured the distributor was dying
also it make a wierd noise most of the time i try to start it like an electric drill

[Hulk Will Smash]

The TBI motors also have an oil pressure sensor that shuts the motor down or puts it in limp mode, I think, when it detects low pressure. Hang in there man! These trucks are super cool. You'll love the convenience of the TBI once you get it dialed in.

[pig rig]

the coolent temp wire is at the thermostat just below it the green wire I'm thinking is to the oil pressure gauge
your truck is OBD1 OBD1 was ued up untill 96 then cam OB2

you can check for codes with a paper clip I suggest you get a chilltons or a hynes manual its got lots of info about the way OBD1 works and it also will tell you what the codes mean
once you get your truck running right you'll realy like it and once you start to understand what each sensor does and how it works you can get more power and milage out of your motor

[pig rig]

just got thinking more about that green wire its the coolent temp switch for the auxiliary fan thats in front of your rad.