No Poker Champ

I'm still at my wits end. My 89 Vet still has me baffled. As I had mentioned in my last post. I have replaced everything from the rooter to the tooter on my vet. That included, IAC, TPR, MAF, Mass Relays, and Fuel pump relay.
I stopped at replacing the fuel pump. I am now feeling my problem is electrical. Reasons being
1) My car will only start and run when I disconnect the TPS and MAF.
It will idle for maybe 20 minutes or until hot, then shut down. I will have to wait for it to cool down again before it starts. Or if I start it up and drive around the block it might make it before it gets hot (not overheating hot).
2) I did a fuel pressure test thinking it might be the fuel pressure. It does not register initially when I do the key on position. But when I start it the gauges goes wildly in the range from 20 to 45. I shut it do and go to key on the gauge drops to 35 then creeps sloly up to 40 in about a minute and stays in that range until I turn the car off completely.
3) therein is the reason I didn't change out the fuel pump. The gauge trickles up to the required 40.

Mt spidee senses are telling me I have a electrical issue (ground).
This all started after getting the 36 code and replacing the part. I now have no codes only when I don't connect the MAF TPS Where do I go now. I really enjoy my vet it ran great prior to the codes. And I don't want to sell it or part it out but I don't know which way to turn

aussie_g

You might want to consider a FPR - Fuel Pressure Regulator.

Sounds to me that is exactly what your problem is.

JMelton

Are you 100% positive that you don't have a massive air leak somewhere?

Tom400CFI

When the symptoms are present and the car won't start....what is missing? Fuel or Spark?

K.I.S.S.

No Poker Champ

It just spins as if there is no fuel or spark

No Poker Champ

No there were no leaks that I could find

No Poker Champ

I had considered that part as well after seeing a Youtube video on checking fuel pump problems. It seemed that if you removed he vacuum line from the FPR and there was a slight rise in the idle the FPR could be eliminated

No Poker Champ

This happens (no start) after I reconnect the MAF, TPS. When I disconnect them, the car starts right up.

Cliff Harris

You might have a bad ignition module (inside the distributor) or it might be lacking the thermal grease which should be under it. It sends a signal to the ECM to let it know when to fire the ignition and the injectors. The ignition module gets very hot when the engine is running and it will shut down if it overheats. It's designed to do that and will recover when it cools off.

tunedport85inject

i've read your previous 3d
timing
ignition
fuel injection/pressure
i mean
is the car at 6 degrees timing ?(est disconnected)
is TPS at .54 v idle (there is a procedure to make it perfect)
do you have a priming fuel pump
do you have steady 43 PSI?
do you have good spark?

did you messed with something that may be wrong?

if you have a good MAF and a TPS sensor tuned at .54v as FSM says,good maf power/burn off relais,steady pressure and good spark the car has to fire up
put these parts on again
set your TPS as for FSM procedure.
ceck your fuel pressure (vacuum disconnected at FPR) at 40-43 psi
ceck your distributor connectors BAT ,TACH,dist 4 way connector
ceck injectors pulse with noid light
ceck for sparks (good sparks are blue )

i had experienced a bad ignition module and the car doesn't start at all,but i can't exclude what Cliff said.

No Poker Champ

I will redo the many things you have suggested. I did a parts tune up shortly after I got the car Aug 2013(plugs, coil. ign mod, cap and rotor). And yes I kept all the old parts.
Even when I put the old parts back in the car I still get the same behaviors. It will only start when I remove the connectors on the MAF & TPS. I even will have the car running and plug one or both of those components in and the car shuts right down. Oh I even replaced the ECM and the same results. Please advise. Again! I would hate to sell it because I think we / I am right on the edge of fixing it. And as it is as a basket case, the most I can get for it may be around $1,500. And that's b/c it still runs. I live in the inner city w/o a garage s parting it out is not a real option.
Wits end

No Poker Champ

I will recheck the ign mod, so as to not over look any options.
The baffling thing is that it starts right up when the MAF & TPS are NOT CONNECTED. A as soon as I connect one or both (MAF or TPS)
The car shuts right down, until I disconnect them (MAF & TPS) again.

summerst

Maybe there is something of use in this thread to help you with your problem:
http://www.thirdgen.org/techboard/tp...n-i-drive.html

Tom400CFI

Well.....why don't you actually CHECK it, and see what is missing. Yikes.

hooked073

first I like to reapir the things that are a known problem. You say you have no fuel pressure when you turn the key on. This is the first thing I would address. the 2nd thing I would check is the tps and make sure it is dead on for some reason long time ago IIRC we had a car in that was driving us crazy that was acting like yours. We made a ton of phone calls to different GM service departments one of my trusted service writers said to chack it sure enough it was way off. corrected it problem solved

hooked073

for the life of me I cannot find my service manual right now but I looked on here and found what should be the correct diagram for the Maf and both the fuel pump relay and oil pressure switch is tied into the maf circuit. You say you have no fuel pressure when you turn the key well the oil pressure switch switch and the oil pressure real both can cause this. Fit the fuel pressure problem first like I said then move on if this does not fix your problem

No Poker Champ

I will go back and check it so as to leave no stone unturned. It only does not start when I connect the TPS & MAF. Otherwise it will start right up usually without a lot of cranking of the engine.

hooked073

100% agree

tunedport85inject

if the car starts with a disconnected maf or TPS and a no start condition comes with MAF TPS on, there's a problem with these 2 devices:

the car may start with and unplugged TPS:ECM uses a "recovery" value for tps and turn the inectors on.

the car may also start with defective MAf but normally she stalls.If you unplug the MAF the same way the ECM uses a default value to start the engine.

this is congruent with your statement:the car starts with MAF and TPS unplugged.

question is :do you have both device/circuit faulty or just one of them?

start the car with both device disconnected and then plug one at a time.

try first with MAF,then TPS.

if both are faulty,or simply both causes the engine stall,go to FSM codes for TPS and MAF and make a circuit check

AGENT 86

If your injectors are factory installed, you may want to ohm test them cold and then hot. The 89 Multec injectors are famous for knocking out the ECM injector driver when the resistance gets low.