ok time for some help...
Ive replaced the computer coil cap bug TPS Idle control plugs wires had the ignition module tested. no codes runs horrible wont idle at all with the brown wire disconnected runs real smooth till you drop to about 1200 RPM then just like you turned off the key it dies.
used the lights on the injectors all working fan doesnt seem to want to kick on changed the thermostat to a 195 someone had a 160 that was locked open in it.
MAF is a year old seems to be dumping way to much gas flooding out
any ideas??

 

Is your timing correct? 6* btdc. Check temp sensor also.

 

Can't really get a light on it
won't idle with the brown black wire unplugged
been timing it a little by ear
but have to adjust the timing when it
warms up

 

Also runs much better with the timing wire unplugged
but won't idle.

 

Sounds like you have the timing fubar'd.

 

Check your fuel Pressure, Do an Ohm check on injectors, check for vac leaks...Is voltage correct for TPS? Check EGR for vac leak, check PCV valve, vac line under throttle body. reset IAC, check all sensor wires for cracks or quick connects, all low voltage wires must be soldered if they were cut and repaired. A biggie is the O2 sensor, it controls lean and rich conditions.

I'm just trying to help give you some more ideas.

 

Thanks for the help im stumped Do these things have any value? i looking to resale if i can get it running right moter was rebuilt in 09 ran good when the guy i got it from bought it he burned up a couple of plug wires and it hasnt run right since its a T-Top car paint is rough but body is straight front end completely redone wheel to wheel new tire all the way around what can i expect to get out of it?

checked fuel pressure ok
how do i ohm check the injectors i used the noid lights all blinked
what voltage should the TPS be at?
how do i reset the IAC
is there a check i can do on the O2 sensor?

 

You can check out the FAQ on the main page for some info, but it won't do much good if your base timing is off. Also check the tech. articles.

 

Is there a way to time it close without unplugging the wire thats supposed to be unplugged?

 

Pull out the number one plug (plug farthest forward on driver's side) and have someone crank (bump) the engine with your thumb over the whole. When your thumb is blown off (the whole not your hand), that is the compression stroke and you will be close to top dead center (TDC). As you are facing your engine standing in front of the car, your rotor under the cap should be pointing to roughly 5 PM. This will be the number one position on the cap. Make sure your plug wires are routed properly. Go around the cap and attach the wires in the firing order sequence 1-8-4-3-6-5-7-2. Prior to attaching to the cap, take some masking tape and label each wire as to which plug it is attached to. To set the timing, you need to pull the electrical signal plug which is over by the air conditioning blow motor on the passenger firewall.

If you pull your distributor out, the drop in isn't perfectly straight. It rotates a little bit as you install it. Gauge the amount of rotation and compensate as needed.

The ECM can rotate timing up to 180* and a plug wire off location will still run (I remember you posted about burnt plug wires, so I am assuming they were replaced).

 

you need to pull the electrical signal plug which is over by the air conditioning blow motor on the passenger firewall.

This is the wire that when i unplug it will not idle below about 1200
shuts off like you turn off the key
ive checked and double checked the firing order
can i time close at 1200 RPM?

 

No.

 

First make sure there are no vacuum lines broke, cracked or off. You may have to try to time it by ear, but it needs to be timed right on 6* btdc for the computer to advance it correctly.

 

Runs good until it warms up a little then as soon as the computer kicks in it starts backfiring popping and coughing if i unplug the timing wire it smoothes back out.
vacume lines were replaced before i got it
when i pul the vacuum line off the EGR valve it doesnt seem to make any difference.
nor do i feel any vacuum when i put my finger over the hose...
i have 2 vac lines on th passenger side that have caps on them?
smog device has been removed completely A/C compressor is off.
computer doesnt kick on the fans...
im about ready to take offers.

 

Smog air pump can be removed with no problems. As for the fans, this could be the fan relay and or the temp sensor on the engine. As for no vacuum, you should have plenty of vacuum at idle, I can't remember off hand the amount, but you should have a noticeable vacuum at idle. I know this stuff can be frustrating, but with some patience you can find the problem. Do you have any repair manuals? They help too. One more thing, and this is big, Don't rely on what the previous owner did as correct, I went through problems the previous owner's mechanic told him were unfixable. A couple sensors and relays, with the proper vacuum lines in place and wah lah, running like a pro. As long as the engine runs, it can be fixed.

 

Thanks redrock it is frustrating hard to
diag when it so inconsistant hard to check
sensors when I don't know what can cause what
to me it's when cold start kicks off and it
starts reading sensors it craps out
I'm thinking about replacing the o2 sensor
and just start there and spend a fortune
one sensor at a time
anyone got an order that I should replace?

 

GOT CODES!
22, 33, 36, 42
logging onto shopkey has wonderfull diag test and flowcharts with schematics
wish me luck

 

You certainly had good advice so far, you can Google GM TPI and find a ton of information. If all else fails you can go to this site and start from scratch. (http://performanceparts.com/part.php?partID=268962).

Remember, your car is right at 25 yrs old. I had a 87 Chevy TBI and when the computer went bad it did the coughing and backfire like you described. I barely made it to the shop and had it replaced. It ran great after that. The bill was $450 back in 97. I use the Internet and web sites like this one to help me do my own repairs. If the code corrections don't fix the problem, see if you can find a 87 IROC that runs good and ask to swap ECM's and go from there. There are a lot of 3rd Gen enthusiast willing to offer advice and help, don't give up and sell your car! I even had Vette people help me with mine on the TPI.

 

I've had a lot of experience with 22,33,36, so any questions, just ask. I was thinking you should of had codes, but then you said you didn't have them, anyway you have a place to start now.

 

Ok well i cleared the codes with a scan tool tech1
and tryed to recreate fesh codes by running the car I hooked up the scanner and read all the stuff but not sure whats right or wrong but no codes since cleared

TPS is running about .6 volts
but.... it has some kind of fuel backup test and when i turned it n car smoothed out and ran beautifully as soon as it kicked out of the test went right back to popping and backfiring.
anyone tell me what im looking for on the setting that im looking at?
it has a load of things it reads what am i looking for?

 

Back up fuel is MEMCAL default fueling test. Its basically a test of your primary fuel management system. Mainly, it checks MAF sensor function. Use the TECH 1 to track MAF voltage as you accelerate from a stop to 60 MPH. Clean the MAF with MAF cleaner, then repeat the acceleration test, looking for an increase in MAF voltage. Check for any air leaks behind the MAF, including around the plenum and intake. Use the TECH 1 to monitor ECT and compare it to actual coolant temp. Monitor datstream and look for anything that may be off.

 

Prom id 8161
Mat intair temp 88
Coolant temp 214
Mass air flow 18
Airflow 17gs
Throttle position .92
Lv8 eng load 65
Oxygen sensor 300-600
Ink pulse width 2.0mSec
Spark advance 0 @ 1100 rpm
Fuel integrater 123
Block learn 118
Closed loop*
Block learn cell 1 cell
Knock retard 0
Knock signal no
Exhaust Rec 0
Egr diag switch off
Idle aircintrol 124
Air control sol divert
Air switch sol converter
Trouble code 42 est bypass fail

anything jump out that looks odd?
Just replaced the MAF sensor seems to
be running a little better but still won't idle

 

Tps should be between .54-.75, (i personally like .65) A code 42, I would check the wires to the EST also check your fuel pump relay. Have you gotten the timing on at 6* btdc?

 

Red Rock,

On a 87, is the ESC mounted on the firewall or is it intergrated on the memcal?

I had a ESC go bad on a 86 Ranger and barely ran.

 

The TPS I think is high because I'm holding
the throttle at 11- 1200 to keep it running
still can't get it to idle long enough to
time it right
noteworthy that it ran better with the code 41
than without it.
Tell me what and where the esc that I'm needing to check?
Is that the module in the dizzy? I pulled it
had it checked at oriellys it checked good

...... Crushers are giving how much for these things??

 

How do I "check" the fuel pump relay?

 

The wire runs on the pass firewall.

 

You need to check the tps with the engine off. The tan wire with a black stripe coming out of the wire loom on the pass. side is the electronic spark wire. You need to go to the main page under tech. articles and click on how to adjust your timing.