I have a good one for one of you tpi genuses. I have an 86 305 tpi that I have to "grind" on in the morning , about 5 minutes to get started. Once started the rest of the day is smooth sailing. I have replaced EVERYTHING and still no quick start up? I have taken advise from every kind of mechanic that you can think of and still nothing. The engine is brand new 3,000 miles or less new holley fuel pump (second pump I have tried) new regulator (stock), injectors cleaned and recalibrated all new sensors including the cold start thermo switch,etc. Is there any other 86 owner that has had this problem? I have checked and rechecked
my fuel pressure the second I turn the key it has 42 psi in the fuel rail. Any ideas, I don't? Kyle

 

Assuming the cold start injector was also "cleaned and recalibrated"
disconnect the PCV hose from the PCV valve and pour a swig of gas through it, reconnect and start, if it starts right up, you have a cold start fuel problem. You should be able to remove the cold start injector from the hole put it in a glass jar, but leave it connected to the fuel rail, temporarily plug the hole and crank to check for flow. if it doesn't flow then there is a fault in the wiring, or the ECM is bad, or the ECM thinks the engine is already at or above oeprating temperature (>170°.) which can also be caused by faulty wiring. Insure that you have good engine and chassis grounds.

Keep us posted.

 

i have a 86 iroc with tpi and i have kind of the same problem, i have to give it a little bit of throttle to get it started, ill bet that the cold start injector if my prob, thanks for the thread, great info

 

I have an 86 305 tpi also. I alo am having the same problem. I've done a plugs cap and rotor, wires, coldstart injector, cleamed the injectectors, and the coldsart injector switch. I still have the same problem. This looks like something common to 86 305 tpi.

 

My '88 does the same thing. The CSI isn't related to the ECM, so if it doesn't flow its not an ECM problem. There is a switch on the front of the intake base that controls the CSI.

 

This sounds like a throttle position sensor out of calibration.
Also make sure that there isnt a bunch of oil or gunk build up behind and around the throttle body blades..

 

Bad oil pressure switch or connection to this switch? The oil pressure switch will prevent you from starting until it builds up a few psi pressure.

 

You're correct, my bad.

 

Does an 86' have one?

It only takes 8psi to enable the oil pressure switch, 5 minutes is a long time to pump up to 8psi of oil pressure.

 

If you're getting fuel pressure with key on and it "stays" while cranking then the oil switch is not the problem. The distributor reference pulses turn on the fuel pump relay each time a pulse is detected. If the relay fails, then the oil switch must close to enable the fuel pump. Sometimes that can take more than a few turns of the crank to operate.
Definatly check the TPS and reset the IAC to be sure they are where they should be.

 

My TPI does the same thing its an 1989. I havent worried about it since it starts after giving it some gas. I think its just a vaccum leak somewhere. My guess was its the o ring seals on the fuel rail or the seals on the injectors. If they are cracked and worn that would definantly cause that problem.

 

A couple of things to think about. Some MAF cars like the starter to be turned over for a couple of seconds and then stop. Then crank again right away. Mine will start right up that way.

If you are getting low voltage to the spark control module in the distributor and the coil because of the current draw from your starter you will have a hard time starting. Make sure your wiring is in good condition and all grounds wires and connections are up to snuff. Allen

 

Yes, that is something GM put into the prom chips in the 89 TPI's and is easily thwarted with chip burning.

 

Was that to preheat the MAF or something?
Sorry to barge.

 

same thing with my 88 350 tpi. it will start hard sometimes doesnt really happen under certain curcumstances. just kinda whenever it wants it will start hard. i replaced the TPS and IAC and they are both spot on havent looked into the fuel system yet and i also need to check out the egr system or the lack of one i should say. anyone take thier egr off? i didnt do it but the guy i bought it from did and i dont know if that is the problem? starts hard and ****ty throttle responce.

 

No, it was GM's way of ensuring that there was oil pumping through the engine before it fired off.

 

I had the same intermittent starting issue with my 1989 GTA 350 TPI for about year and I was getting bad mpg. Some days it would start okay and other days it would take awhile. I replaced just about everything: tps, iac, spark plug, wires, alternator, egr, pcv, still yield no result. Turned out to be a FUEL PRESSURE REGULATOR that was going. It finally went out on me last month as I was driving home from work. I had to get my car towed because there was fuel everywhere. The FUEL PRESSURE REGULATOR only cost $23 at Autozone. I suspected this way back but was too lazy to even change it. Now it starts everytime and my MPG has jumped from 10mpg to 15mpg city.

 

Get yourself a new or used MSD 6 or 6A and she will fire up right away.

 

what kind of running problems did you have? because somtimes i will sit there and crank it for a while then give it some gas and then it will fire. and then the next day i can just turn the key and it fires right up? and it also get horroble gas milage. when a fuel pressure regulator goes "bad" what actually happens? does it not keep the same pressure each time the pump is cycled? or does it leak pressure offf? or what? if you had these same problems with your 89 let me know. i will get an ajustable regulator from T.P.I.S thanks!

 

The problems due to a bad fuel pressure regulator are lost horsepower, excessive cranking time, and poor gas mileage. First, somedays the car would not pull as a hard as if I lost some horsepowers but other days it hauled azz this was intermittent. Secondly, it would require a good 6-8 second of cranking (engine cold or hot) before firing. And when it fired up, the RMP would drop so low that the engine would want to die but would pick right up again instantly. Idle is always smooth and was never an issue. Some days it fired right away and would take a second to crank but still the rpm drops and almost sputters for a second as always. Thirdly, another symptom was poor gas mileage at 10 mpg city and 13 mpg highway. Within a year I replaced the following: computer/chip/ignition module/distributor/oxygen sensor/spark plug/wires/TPS sensor/Idle Air Control/Fuel Filter/Air Filter/2 catalytic convertor. After 15 years it was a good idea to change the above parts anyway. The best I could pull with my tuned stock 1989 GTA is 6.1 sec 0-60 mph – 14.7 sec in a 1/4 mile via G-Tech. However, with the fuel pressure regulator problem my times suffered with a 6.9 sec 0-60mph 15.4 sec in a 1/4 mile via G-Tech. So the verdict - CHANGE THE FUEL PRESSURE REGULATOR!

 

I agree with CALIROC get a high out put ignition, replacing every part of your ignition doesnt even come close to the spark power of having and after market ignition.
I used to have a motor that spitted and sputtered and burned a little oil which fowled my plugs easily that was until I got a Crane Hi 6 ignition with a blaster 3 coil. The spark was so strong that even with bad plugs the motor fired right up all of the time.
and the spark jumped 6 to 8 inches compared to barely seeing the stock spark with a stock everything new tune up.