compositecrafte

Bought a 1958 Chevy 4x4 truck with 350, thought I would convert to 88 TPI and completely rebuild engine. Completely rebuilt TPI powdercoated, all sensors replaced with GM units, New injectors 22lb Stand equipment GM units all tested ohms and conections. Complete new fuel system from tank sender,pump,filter,lines tested 35psi idle 40 or so under acceleration. New regulator,Dist,Wires, Plugs no expence spared. TPS read .50volt O2 sensor works perfect even checke for correct ground at the computer plug and wiring to o2 sensor checked OK. Ive checked coolant,O2 Tps, IAC, knock.
Problem is: after warmup and entering close loop operation, the engine stumbles trys to keep running then dies, it will always die if the elec fans kick on. I have replaced the MAF with a New unit, not rebuilt. Today it seem to be ruuning good and upon acceleration stummbled really bad and would not gain in rpms. The truck has 2 brand new batterys wired together, since truck has wench, so I know the batteries are good, New high amp gm one wire alt. Everything is grounded with new grounds and I mean from everywhere,starter,block,alt,back of block,cab have even checked at the computer harness plug was ok. New computer, computer chip is from a 88 350 and i purchased a No vats bypass chip that plugs in before factory chip, chip bypass programmed for no egr,no startup injector,no vats,no speed limit. I get no codes but 12, I have tried unplugging Maf during running, Nothing, I have reset the IAC several times, nothing. Runs great intill it goes into closed loop, I have switched out computer, nothing still same. I have replaced the new electronic unit est in distributor, still nothing, I have replaced ESC module, nothing, I have purchased the Chevy TPI swappers guide, still nothing.

rgarcia63

Try, disconnecting the vacuum under the TB for the EGR solenoid and plug it. Take a test run, you might get a code.
Do you have headers?

compositecrafte

Tpi has EGR blockoff plates, Header are stainless steel with O2 sensor within 8 to 10 inches. I have read that the bung should be installed no father than 12" so the o2 can heat to 600 degrees before it enter closed loop operration.

BuzzLOL

.. Have you read the "Performance Prom" stickie above?

compositecrafte

Just read through the Perf Prom thread, Nice. I'm running a stock 88 350 camero chip, I'm just looking for a good running stock setup, but I still have the problem of closed loop hesitation and rpm drop off??

305sbc

iTrader: (3)

I would hook up a laptop and do some datalogging. Getting a good look at the BLMs and sensor readings would probably point you in the right direction.

Have you tried a heated O2 sensor yet? I ask because you have stainless headers and you said that the problem starts once you go closed-loop.

rgarcia63

The O2 was the reason I asked if he had headers because I had the same problem and after disabling the EGR, and doing some data logging I saw that the O2 was cooling off when it should have been nice and warm so I switched to a heated O2 which solved my problem.

Raul

compositecrafte

I'll order one today, I'm going to try and stay clear of the Bosch brand as I hear they don't work as well

compositecrafte

So I have a Heated O2 sensor kit coming, and hooked a cheap $40 code flasher from autozone today and started the truck, during open loop it flashes fast, once it switches to close loop it slows. it takes a couple of mins to switch from open to close. but I noticed from time to time the light would hold solid, Im not sure what this means, but judging from the poor performance I take this as some sort of O2 fault????
During open loop/just started it has Great thottle, Neck snapping! Close loop it grumbles to build rpm's.
I would also like to know what and where I would find software and plug to hook my laptop into the system. I only have a cheap code flasher.

Tuned Performance

iTrader: (92)

You bought a $40 paper clip

Tuned Performance

iTrader: (92)

http://www.moates.net/aldu1-and-cabl....html?cPath=64

I bought one of those years ago for cheap and it had wheel weights in it. I modified the case and installed a board to work with winaldl.

compositecrafte

Yes, but it comes in pretty plastic, with really neat writing on it. Im a plug and play sort of person, figure it was nice that it plugged in neat and clean. I have used the paper clip, but there so small and get lost all the time.

compositecrafte

I'm learning as I go, someday when I pass this on to the next person, they with figure out one side plug into the other. Only Perfesionals know the paper clip trick.

BuzzLOL

.. I was trying to resist saying that...

compositecrafte

Well, I installed the heated O2 sensor kit, checked connection and power. It seemed to run slightly better but every time the electric cooling fans came on the engine sputtered and Died, I restarted and tried to keep it running but I could not get any RPM's to build up.
I am running the cooling fans off a seprate wiring harness, that is not connected to the TPI system in any way, it has its own Temp sending unit and the relays are wired directly to the second battery, the fan relay trigger wire is hooked in to a seperate fuse panel used only for truck lighting and in no way is hooked to the stand alone TPI harness.
I tried to hook the fan relay trigger from the TPI harness that should start fans at 210 degrees but the fans never triggered. the truck temp got up to 240 Degrees and started to shot coolant out the overflow. No sure why the cooling fan wire from TPI harness will not trigger Fans.
So I purchased a Hypertech chip to see if that might be the problem, still would no trigger the fans via the TPI harness so I reconnected the fans to there own system, but once the fans are triggered at about 180 on there seperate wiring system the truck still dies. I cant figure that one out.
I order the above datalogging system so I can hook my laptop in so Im still without a clue.

compositecrafte

Ok so I figured out why I am not getting the computer to start the cooling fans, the Grn/wht white from the stand alone harness is for ground and does not trigger the relay with 12volt, it only completes the circuit by grounding. So tomorrow I will retry and see if I can get the computer to start the cooling fans.

BuzzLOL

.. Shouldn't need the fans while driving on the open road... have you tried disconnecting the fans and driving in closed loop?

.. Sounds like there's a shortage of juice somehow for both the fans and ECM/injectors...

.. Should be 14.0 - 14.2 volts at battery at all times when engine is running...

john36mc

let me know how you are doing i have the same problem.

vetteoz

iTrader: (13)

Need this cable for data logging
http://www.aldlcable.com/

http://www.ttspowersystems.com/DataM...ownloads2.html
http://www.tunerpro.net/

compositecrafte

Ok, well after X-mas dinner and perfect weather I went out to trouble shoot and am more stumpped then before. Upon starting the truck in open loop it runs Great, with the New Heated O2 it takes less than a min to go into close loop and then the truck Stumbles and tries to keep running but dies, if you put it into gear it will stumble and die as well. and for some reason the truck Smells very rich!
I was thinking that the computer can not tell what the the fuel pressure is and if the injectors are leaking or not.
The fuel presure is 35lbs at idle and upon thottle can go as high as 42/43lbs.
The only other thing I can think of is that the (New) Standard Equipment OE injectors might be leaking????
What other reasons would the truck be running so rich????

compositecrafte

Can someone tell me if there are a better injector, maybe one that doesnt use a pintle. I have heard that some have 4 to 6 holes and use another method like a ball or disc.
I am looking for 22lb, I think stock 88 camaros have 22lb?

compositecrafte

I order the Moates ALDU1 and CABL1 XtremeALDL and NewCAB1 Combo
http://www.moates.net/aldu1-and-cabl....html?cPath=64

cuisinartvette

Have you checked the Coolant Temp Sensor out?

vetteoz

iTrader: (13)

If CTS is sending wrong temp info to the ECM then ECM will give wrong fueling
Worth the $14 cost to check

or you can check with a DVM
http://www.chevythunder.com/cts_diagnostics.htm

compositecrafte

I have replaced the New temp sensor with another New temp sensor, still has problems. First Temp sensor was an AC Delco unit, Second Autozone.

I noticed that the fans come on during start up and its winter. I have read this is a sign of a Bad computer, and it is in Limp Mode. Wouldnt there be some sort of Code set?? I have also read that if you take the computer chip out or hook a different computer to the harness without installing the Chip and the fans come on the computer is Bad and in Limp mode????

compositecrafte

Tomorrow I will run a Ohms meter on the coolant sensor to check.

vetteoz

iTrader: (13)

Usual sign it is in limp home mode.
If ECM is not seeing correct input from essential sensors it will also go into limp home

compositecrafte

The Check Engine lights on start up to indicate Good ECM.
I really need to get my new datalogger to see whats really going on, but upon first starting in open loop it runs really good, but I dont know if the computer controls this aspect of first startup to closed loop operation?
I never thought going to Fuel injection would be such a Pain, I just wanted reliablity and fuel milage on a vintage 4x4.

compositecrafte

essential sensors being, Temp,O2,MAF,TPS,IAC,Knock, and Dist feedback ??

I know the two main sensors are the Temp and O2, I was hoping by going to a Heated O2 this would fix the problem. I even checked the O2 wiring form the computer to sensor and checked for proper ground to the computer to O2 and all was OK. Today I turn key to Ign on but not start and the O2 did get Warm but not anywhere near 600 degrees? I even checked it with a heat probe and the outside temp of the O2 was 222degrees. I guess the 600 degrees is an internal temp?? The computer did switch from open to close in about 1min to 1 1/2mins so I guess the computer got the signal from the O2 that it was at the 600 degree mark to make that switch ??

vetteoz

iTrader: (13)

No feedback from IAC .is only controlled by ECM as it tries to adjust idle to set figure
No dist ref signal ; no injector pulse = no start
Knock I am not sure.
ECM does self test on KS , if faulty it will limit spark advance over 1500 but should not affect CL idle problem
that you are getting

There is a timer in the programming that delays CL operation.Stock it is 180 seconds from cold before ECM looks for O2 signal
Heated O2 only makes the O2 work; ECM is looking for the varying hi/low voltage signal from the O2 ; not the operating temp

Datalogging will let you see exactly what inputs the ECM is getting.

compositecrafte

OK, so I think figured out that if you have the ALDL pins a an b shorted for code mode and service test mode the fan come on during key on ign. With ALDL not shorted the fan with not come on during Ign on/Key on.

rgarcia63

True.

compositecrafte

Well today I thought I would try to disconnect the heated O2 sensor during closed loop when the truck begins to shutter and sputter, I then hooked a normal one wire O2 and kept it sitting not screwed into the header. The truck seemed to run much better but still very Rich. I also notice there seems to be more water vapor coming from the exhaust side with the O2 sensor in.
I also changed the New AC Delco IAC sensor with a New Autozone unit, still same problem.
Then changed the whole computer and chip with a spare I have and still same problem.

john36mc

I feel your pain I also have changed every censor and part on the tuneport system. mine wont run on start up with the maf plugged in . but it runs good with it unplugged. it is a pain in the ***.

compositecrafte

Im guess I should have went with a EZ EFI computer and harness combo. I thought that by going with a GM based system I would have better access to replacement parts and a system to has been proven.
Yesterday I was at Pepboy and seen they had a INNOVA 3120 scan tool that can be used for an ODB1 system for $199 so I purchased it why I wait for my Datalogger and the INNOVA cant connect as when i enter a 1988 with the 8th digit being An 8 for (350) the scanner just goes blank and returns to the first screen. Yea! Ha! just add it to the spare parts Pile.

compositecrafte

The only thing I can think of at this Point Is to remove the upper TPI and check for Leaking Injectors, They are all New but this seems to be a large problem from what I read. I have a second set of new Standard Equipment Brand injectors. I was hopping maybe other readers might tell me of a higher qaulity 22lb injector maybe ACCEL?? something that has several holes vers just one.

rgarcia63

If you do tear it down to test for injector leakage and don't find any, before reassembly test for flow imbalance by:
Removing coil to distributor spark cable.
Place glass container under each injector and cycle the engine for 1 minute.
Allow the fuel in the containers to settle, check for difference in levels and for contamination especially for water which will separate and sink to the bottom.
Won't cost you much more than time and a little gas.

john36mc

I am struggling with my home made harness I removed from a firebird. what did you do with the ground wire for the park and neutral switch? I have mine in a p/u also

vetteoz

iTrader: (13)

Should start a new post over here
https://www.thirdgen.org/forums/elec.../?daysprune=-1

instead of jumping in on a unrelated one

john36mc

are you replying to me? I was try to help him out because if he didn't hook the wire up to a ground in park it wouldn't run right.

compositecrafte

I have a switch hooked to the ground.

305sbc

iTrader: (3)

You may be on the right track now checking for a mechanical problem on the bank that feeds the O2 sensor. It seems to only act up when the ECM takes control, and that control is based on what it sees in the exhaust on that bank.
If you have too much O2 or fuel delivery on that side for whatever reason it could very well be the cause of the rough running.
I would try putting a wideband O2 in your O2 hole and try to see what is going on there. Better yet you could add an extra bung for the WBO2 near your original O2 so that it will go closed loop and you can monitor the true AFR that way too.

1MeanZ

iTrader: (9)

gotta get a datalogger on this and tell us what the ECM is seeing for inputs, plain and simple. You're flying blind until you can see what data the ECM is seeing.

compositecrafte

I currently Have 4 ECM 7165 units, 3 used, 1 new reman from auto zone. Then I have 1 stock 1988 camaro 350 for auto, memcal with a bypass hooked in front of it, and 1 Hypertech 88 camaro 350 for auto. Today I figured out why the Innova scan tool would not work .My ALDL plug needed to have the Orange (M) on the plug moved to the (E) location serial data.
I ended up getting a code 41 ECM ,42 EST ,43 ESC ,45 O2 RICH ,52 ECM FAULT ,54 FUEL RELAY.
Now every sensor is new and has been repleced with a second new sensor. $$$$
The ECM with the ALDL papercliped shows No faults, but truck does stummble and die after closed loop and very rich. But the Innova shows all these codes???? cant figure that one and everything is NEW.
So tomorrow I will play switch out with the ECM, does anyone know where I can have these checked or a way to self check ECM/computer.
I'm holding off checking the injectors till I figure this out.

john36mc

The switch you have on the park and neutral ground.do you switch it so when you are driving around you get a electric vss signal on the transmission?

compositecrafte

Yes the switch is hooked to the sterring colum, Yes the VSS is pulsing. After getting my Pepboys Innova 3120 scanner to work seems its coming up with the idea my ECM has a problem, but the self test on start up say's differnt, it's says everything is Good???? Very confusing. I guess it should be exspected on a 20yr old system.
I am thinking of just going to some aftermarket compter.

compositecrafte

If I am having trouble like this and everything is New and I have 2 or more of everything, what happens when Im miles in the back country and something goes wrong with this GM TPI??

compositecrafte

I was looking for a reliable system whitout getting into a Master mechanic PHD.

john36mc

i feel your pain . I thought you already tried computers? I can only get mine to run with the maf unplugged . I just ordered all 3 relays. time will tell. you don't have a friend with a scanner that you can do some logging? I have one but i don't know what all the symbols mean.

compositecrafte

I tried 2 computers so now I guess Im going though all of them, I ordered a datalogger, so Im just waiting. But I really wanted a trouble free setup, user friendly and this system is not user friendly. Thats why I was thinking of cutting my loses and going with a aftermarket userfriendly system. I dont mind some trouble shooting but there are limits to my free time.