Hey Guys I Need Help Quick

[someotherguy]

If you have access to one, a small propane bottle with a torch nozzle (UNLIT obviously) I find easier to control than spraying carb cleaner around.

Richard

 

[Nick88]

At this point all you are doing is guessing,hook a scan tool to the truck and find out what live data is telling you.

I’ve used a multimeter to test the other sensors and they came back good backblading and testing resistance, the whole issue is a don’t have a scan tool and I’m not even sure what to look for, I’ve tried looking it up but all I can find is those little obd1 ”scanners” that work the same as a paper clip in the diagnostic terminals.

 

[Nick88]

If you have access to one, a small propane bottle with a torch nozzle (UNLIT obviously) I find easier to control than spraying carb cleaner around.

Richard

The only thing that bothers me about if it is a vacuum leak is it kind of happened out of no where and I havent touch the vacuum lines recently at all, just before the truck was idling like a brand new car and was driving amazing, it mostly started after touching the grounds but they are clean and tight so I’m at a loss.

 

[someotherguy]

You've got something to go on there. "Always suspect prior work" even if it's your own. The grounds may have been marginal before, and cleaning them might have put a connection over the edge.

Like Erik said you might replace the connectors at the ends, but I'll take it a step farther and suggest you consider checking the wiring diagrams and unplug them to ohm them out see if the wire is damaged. If you haven't checked the ground straps from the rear of the passenger head to the firewall then from that same spot to the frame, those are often suspect, too.

The CTS (ECT) circuit operates off resistance, and the higher the resistance the colder the ECM thinks your engine is. Your sensor may read correctly at the sensor's socket itself, but if the circuit has excess resistance due to wiring damage or ground issues that can throw the signal off completely. A scanner with live data would show you what it's reporting to the ECM. Lacking that we are guessing for sure, but you can at least ensure the wiring and grounds are all good.

Richard

 

[Nick88]

You've got something to go on there. "Always suspect prior work" even if it's your own. The grounds may have been marginal before, and cleaning them might have put a connection over the edge.

Like Erik said you might replace the connectors at the ends, but I'll take it a step farther and suggest you consider checking the wiring diagrams and unplug them to ohm them out see if the wire is damaged. If you haven't checked the ground straps from the rear of the passenger head to the firewall then from that same spot to the frame, those are often suspect, too.

The CTS (ECT) circuit operates off resistance, and the higher the resistance the colder the ECM thinks your engine is. Your sensor may read correctly at the sensor's socket itself, but if the circuit has excess resistance due to wiring damage or ground issues that can throw the signal off completely. A scanner with live data would show you what it's reporting to the ECM. Lacking that we are guessing for sure, but you can at least ensure the wiring and grounds are all good.

Richard

Any idea where I would be able to find one of those scanners to get live data for obd1?

 

[BVRPLZR]

You said the new O2 sensor was a Bosch unit.

I've read a few times that for whatever reason the TBI's don't like the Bosch O2 sensors. I believe it was RBob who mentioned it in an EBL Flash tuning thread on thirdgen.org? I can't remember, but I do remember reading some grumbles about TBI and Bosch O2 sensors.

As far as a scan tool, check Boosted NW. Make sure you're getting the connector with the correct number of pins. I think they come in 10 and 12 pin varieties.

 

[Pinger]

Going slightly leftfield... is the ducting leading to the air filter clear of obstruction?

 

[Frank Enstein]

Worn timing chain? Check the timing. If it fluctuates it is likely the chain.

 

[Scooterwrench]

The only thing that bothers me about if it is a vacuum leak is it kind of happened out of no where and I havent touch the vacuum lines recently at all, just before the truck was idling like a brand new car and was driving amazing, it mostly started after touching the grounds but they are clean and tight so I’m at a loss.

May want to check the ground wires up from the terminals. Could be one was corroded up inside the insulation and disturbing it finished it off. Pull the grounds loose again and flex the wires. A the wire will feel limp where the conductor is broken. Now would be a good time to find the schematic for that truck so you can check your grounds point A to point B with a continuity tester.
A quick check for a sticking injector would be with a stethoscope or long screwdriver. While the engine is running touch it to the top of the injector and listen for the clicks. If the injector is not ticking while the engine is running and it is spraying during prime you may have a shorted driver in the ECM. If it does spray during prime unhook the injector connector,if it quits it's definitely the ECM,if it continues to spray it's the injector.

 

[Nick88]

You said the new O2 sensor was a Bosch unit.

I've read a few times that for whatever reason the TBI's don't like the Bosch O2 sensors. I believe it was RBob who mentioned it in an EBL Flash tuning thread on thirdgen.org? I can't remember, but I do remember reading some grumbles about TBI and Bosch O2 sensors.

As far as a scan tool, check Boosted NW. Make sure you're getting the connector with the correct number of pins. I think they come in 10 and 12 pin varieties.

Do you think it would be possible that it just randomly went out, because it seemed fine before with the Bosch unit