I was wondering if I could ask for some advice. I Have a 95 TA with a 6 speed. I Did the LT4 conversion about 6 months ago. While doing the conversion I removed the AIR pump and EGR valve, and also replaced the Opti. The thing was running great until recently. Lately the car has been running really rough, and will sometimes just cut off, even when driving down the highway! But at other times it runs just fine. I Just replaced the coil, plugs and wires, and cleaned the throttle body. I also just replaced the Opti again since I had a extra laying around. What should I do next?

 

Check your MAF? Tap on it with a screw driver or somethign and if the RPM's go up, you need a new one.

 

I'll try that. If I can keep it running long enough. thanks

 

I would also see if you have any vacuum leaks. I've had a couple vacuum leaks before that have shut the car off while cruising, and very rough idle.

 

Tried it and there was no effect what so ever. Someone mentioned my IAC valve, but would that still cause it to cut off driving down the road. Usually before it cuts off the RPMs get really erratic.

 

So heres an update. About 2 weeks ago the car cuts off in the middle of an intersection and won't start back up. I have to get the car towed to the dealership. And before every time this thing stuttered or cutoff I always got a "Service Engine Soon" light. So the entire WEEK my car is in the shop she runs like a dream and never cuts off or stuters once. The guys at the dealership didn't charge me for my diagnostic because they seen no problems. But The day After I picked it up it was raining and it cut off again! It only seems to happen if the humidity is high or something. And Now it takes a solid 3 minutes to start everytime, about 5 or 6 tries. And Advice?

 

what do u mean it takes 5-6 times to start does it start up and shut off to where u have to restart it again? cause thats what mine is doing.. everything that i have done all the dianosing has pointed to the opti and the pcm

 

Fuel Pump?

 

 

Looks to me like it wouldn't have hung on this long. We tried this on our Blazer once to see if it was getting fuel--while someone was cranking it, poured gas down the throttle body and it started. Turns out it wasn't getting fuel. On the forward fed intake, this would be nearly impossible. I would start by turning the key on and seeing if you can hear the fuel pump prime up. If so, try taking an injector off and see if you can get fuel running out of the rail while you're cranking.

 

i sprayed starter fluid in the TB on my 93 once when it wouldn't start and it fired right up.

 

It cranks but won't start right away. I replaced the fuel pump and filter and checked my fuel pressure on the fuel rails. The pressure is good. Sometimes the thing works perfect, and other times...well. I have all new plugs, wires, coil and opti. maybe it is my ignition module?

 

if ur ignition module was bad it would throw a code 43 or 42 ignition grounded..i just replaced mine after checking everything else.

 

I'd look at that ignition module; I had a similar experience and after checking the usual suspects it was the ignition module. It didn't throw any code specific to the module.

 

This happened to me, it turned out to be a bad starter AND alternator Mine died in an intersection too, rpms were erratic before it happened, wouldn't restart. Then it turned over when the tow truck guy got there