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99 obd2 pump troubles

So It starts without the cps. Plug that back in and unplug the optic sensor and see if it starts. You dont need to drive it a single mile.

Whats with the switch idea? What are you trying to do?
 
I think he's talking putting a disconnect switch in line with the CPS to turn it "off" once the engine warms up.
 
blumpkin said:
Thankyou everybody for your help, good info, it looks as iff i have to disassemble the air intake pipe to get at it,. I have been busy, so i've been putting up with the long crank times.
(22f) here.
Click to expand...

It's Six bolts (10mm heads) and a clamp for the turbo. T Shirt type of job even in your weather it goes so quick. Be careful putting the bolts back in as the front and rear strip real easy if not already stripped.
 
We had a warm couple of days,.
I unplugged the O/S, it cranked a long time then fired, revved to 900 then promptly stalled, i did this 3 times then added a little throttle to keep it running but it surged constantly like an alcohol blown motor. So again i plugged everything back in and tried a koko. It ran a little lumpy changed its tune then ran smooth!!
So i thought i had it fixed, i was pretty happy,. It drove great for 2 miles then i stopped at a stop sign and the real rough idle with clouds of smelly smoke was back,.(retarded overfueling)
I disconnected the cps sensor again,. And we are back to long crank times, runs shifts great, just no cruise control (which i had for 2 miles)
 
I have a wiring dia of ecm, so i am going to run 3 new wires, i will cut and solder on to the 2 inches or so at ecm then to the cps plug by the thermostat and solder on to 1" before plug. If that doesn't work then i guess last resort will be an ac delco cps instead of bosch?

Thing that is bothering me is i was playing around adding the two fast idle pins and wires, ( they work fine) and i noticed a dk blu wire and a grey/ blk wire cut and soldered and both wires runing over to behind the cluster i think,.
But my wiring dia doesn't really tell me which plug is a/b/c/d etc and there are more than 1 dk blu wires,.
Sure is a learning curve at the moment.
 
I would swap the bosch for an AC Delco sensor first.

2 reasons:
1. Chopping into a harness is a last option. If it fixes it- great. But problems reoccur now there is a new fail point. Proper protocol.

2. Bosch does a bunch of things “good”, sensors from bosch are down a step in the “ok” category. AC Delco some things “good”. But their sensors and thermostats have been the “best” for 4-5 decades running.

If a sensor is really easy to get to and less than 1/2 the cost of AC Delco, I would try bosch. But being a hard to get to sensor, I will only run AC Delco. Gm, Ford, Nissan- don’t care- it gets an AC Delco. It is not about brand loyalty. Motorcraft has always made the best solenoids, actuators, door pins, etc.
 
Also check the terminals inside of the plugs. Make sure there is absolutely NO discoloration and that they are bright and shiny.
any terminal that is even a little bit dingy looking is creating resistance. with the low voltages, any resistance whatever is going to affect the way the voltages are going to be read at the ECM.
I plugged up a thread of postings about the woes of cleaning terminals on My 2000. After everything was set right, that now is one sweet running truck.
 
Crazy update!!
So i had the bright idea to run a new cs signal wire i unpinned the yellow wire from cs plug ( had 5v and groud ok) ran it direct to ecm.
Bupkiss. I tried to koko,. No luck almost as if truck was stuck in koko, idle slow tons of smoke then a quick rev with advance to 8-900 rpm then idle again. So frustrated i read the interwebs again, and a short thread where guy had same problem about 2wks after a new pmd. A pump guy told him to use his original resistor and it ran fine.
I pulled the plug on mine ( on heat sink on inner fender) and looked at resistor, scratched my head looked fine,. So i plugged in my other pmd then first thing i cleared codes and initiated koko then fired it
Holy F!!k idle smooth,. Took it for a drive,. Perfect no check engine lights, went to town did errands multiple shut offs and starts all good!!
So a bad resistor?
One other thing i learned, you can unplug optical sensor fuel temp wire into ecm and it makes no difference!
Can i assume the ecm goes from closed to open loop at 175f?
so the resistor plays a big part in transitioning from closed loop to open? Which happens at 175f,
 
3 weeks later and truck is still running perfectly,.
I bribed a guy to put his tech2 box on it, it has 10.5 deg advance at idle with -1.50 offset. The guy decided to try and do a tdco learn and it started to run rough and smoke, ( i freaked a little) so he cancelled it and all is good.
It is getting a steady 19.2 mpg overall.
I now have plans to add the better exhaust, and a H1c turbo, and then a tune.
Thanks to all that contributed.
 
LeroyDiesel.com has the Diamondeye 4” exhaust and tunes by Kojo. If you can manage to keep from playing with the go fast pedal once you get those 3 installed, you should see a bit better mpg, power, and lower egt/ect temps.

Are you going to do anything else like coatings on the new turbo or inner cooler/ exchanger?
 
blumpkin said:
3 weeks later and truck is still running perfectly,.
I bribed a guy to put his tech2 box on it, it has 10.5 deg advance at idle with -1.50 offset. The guy decided to try and do a tdco learn and it started to run rough and smoke, ( i freaked a little) so he cancelled it and all is good.
It is getting a steady 19.2 mpg overall.
I now have plans to add the better exhaust, and a H1c turbo, and then a tune.
Thanks to all that contributed.
Click to expand...
The rough running with a TDCOffset is normal, freaked me out the first time. It does that then learns a new offset and then smooths out.
 
NVW said:
The rough running with a TDCOffset is normal, freaked me out the first time. It does that then learns a new offset and then smooths out.
Click to expand...
I don't remember if it was the Offset or Learn that it ran rough. All I can remember is I had just got my GMTDScantech and did it the night before I had a 3 hour trip. I had wished for about a 1/2 minute I had left well enough alone:)
 
offset relearn freaked Me out too the first time. engine stalled, advanced the pump, engine fired up and run rough, black smoke, then smoothed out and run as it should.
 
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well spring is here and truck has been working great,. i'm looking for a h1 c for it, then i'll get racedaymechanics adapter stuff,. It has 1 glow plug dead now so very cold starts are a little smokey untill that hole lights off.
i wont be doing an intercooler, but will definitely see which water pump is on there and likely get the better fan too if i change it,. truck js only a part time people mover grocery getter.
I did add 4 led headlights with fancy relay setup to have all 4 on hi. its painful to look at i also added led bulbs to all interior and door lights, perfect for older guys that dont see as good in the dark anymore .
 
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