Looking for a little help. I have a 89 GTA 350 TPI. I bought the car as a theft recovery 10 years ago so its been sitting around a while. I rebuilt the motor and tranny. The problem is that it really hard to start and when it does run it seems sluggish when you step on the gas. Other times it wont start at all - those times its getting no fuel. Fuel pressure is good. New FP relay as well. Scanner will pull no fault codes. My first thoughts are the ECM or PROM but could a ground wire becausing all of this? TPS is reading .64 volts prior to starting. Scanner says VATS is working fine. Also the primary cooling fan comes on shortly after turning the key on. Thanks in advance.

 

Welcome to the boards! Sounds like a fuel pump, maybe a bad fuel filter or clogged injectors. What is your fuel pressure while running. The filter is cheap and easy, the pump is neither of these things. Sometimes if you tap lightly on an injector it can help unstick it. Just some possibilities.

 

Thanks for the welcome. I have replaced the Fuel pump and filter. Fuel pressure is right around 43 psi. And you are correct changing the fuel pump will expand you vocabulary.

 

Check the injectors with a noid light. If they are firing you can start ruling out electrical. Have you checked your distributor and the module in it? What is your timing set at? When you said it was not getting fuel when sluggish, how did you check this?

 

Actually I havent done that. I know I skipped a few steps by not doing that but no place near where I live had them. I made an assumption of them not firing because the there were no fuel on the plugs. As far as the dist module I am getting rpm during cranking and the shop manual says that should rule that out - I dont know if thats true. I'm not sure what was causing it to be sluggish once it did run. I checked the spark and it is ok. I do need to check the timing again though.

 

Check your MAF sensor and air filters, a combination of too much dirt caught on the MAF screen and dirty filters cause my 88 Iroc to be slower than molasses.

Also check to see if your injectors aren't too big or sticking open when throttling, too much fuel will also bog the engine. Best thing to do is get it to run, let it get to operating temperature (when the temp needle stops climbing), let it cool off for a few minutes and Ohm the resistance in the injectors, your manual should have the values, worked on my 305.

Here is a chart with the resistance values.


Hope some of this helps!!

 

When I first got the car back together I thought that injectors may be the problem because at first it seemed to foul the plugs with too much fuel. I did put in a new air cleaner. As far as the MAF goes I tried uplugging it to make the ECM use a default signal and did not change the symptoms. I measured the resistance of the injectors prior to operating temp and they were all over 10 ohms. Thanks for the chart!

 

But was the resistance within the specs in the chart?? If it is lower you are running rich because it takes less power to open the injector which means too much fuel, if they are more than you are running lean which could bog the car too.

 

If I remember correctly the manual stated to replace any injectors with less than 10 ohms. I might be wrong I will have to double check that tonight. I dont recall seeing a chart like the one you posted.

 

I am really leaning toward injectors. Check resistance and go to autozone and get a cheap noid light. I assume you have checked the injector fuses in the box.

 

I checked autozone they do not carry them anymore. I will order online and post what I find out from that.

 

The manuals are kind of general, they cover all the options, engine and equipment things, I got that chart from Alldata (shh I get it at school) and it was specifically for an 89 Trans Am, and thats where your resistance should be, it might be different in the book because that make be for when it is running or when the injectors are hot.

 

I borrowed a noid light and found that infact the injectors are getting a pulse. However the engine has to crank for about 3 seconds before noid will begin to blink. I assume this lack of fuel during the first few seconds of cranking is causing the hard start. Any ideas?

 

Perhaps a break in a wire and it take a minute for the electricity to bridge the gap, causing heat to build up and expand the wires so they touch. Or the computer isn't getting a signal from something right away and it takes a few seconds