When I start it, it cranks for a long time and usually takes two tries to start. Then when I give it gas it falls flat on its face. Once it fully warms up to operating temperature it seems fine.
Today I got a can of Seafoam and split it between the gas tank and a vacuum line, then ran it around for a bit. I'm thinking it's a fuel pressure issue. Any ideas?
It could be 2 issues. Your 'cold start' injector is not doing it's job for sure......but the reason for that is not clear....the other problem may be partially blocked injectors, which should get better with seafoam. Have you checked your fuel filter?
The cold start injector is only active during cranking when the engine is cold. Once the engine is running, the cold start injector is not operating. If the engine runs poorly until it's warmed up, it may be the temperature sensor for the ECM, improper fuel pressure, etc.
------------------ Rod Schneider, Ball Ground, Ga. "You can't have too many toys!" 1988 Fiero GT 1987 Porsche 944S 1987 Corvette 1966 Porsche 911 2001 Chrysler 300M Van's RV-6 airplane
I'm going to test the CTS on Monday. Any methods for testing the CSI?
You could unplug the fuel pump and start the car. If the cold start injector is working it will start for a second or two before dying. I just replaced the fuel pump on my GT today and forgot to plug it in and this is what it did, so it told me the CSI was at least functional.
You could unplug the fuel pump and start the car. If the cold start injector is working it will start for a second or two before dying. I just replaced the fuel pump on my GT today and forgot to plug it in and this is what it did, so it told me the CSI was at least functional.
The cold start injector is just that an injector. It opens when voltage is applied. If there is no fuel pressure behind it no fuel will flow through the injector. So unplugging the fuel pump will cause no fuel to flow thought the injector...
+1 on the fact that the cold start injector is only activated during cranking. It has NO effect on a running engine, unless leaking and allowing extra fuel into the intake. Since your complaint isn't too much fuel in the intake all the time, looking at the cold start injector won't affect your cold running problem.
Does your check engine light illuminate with the key on engine off? It should. If it doesn't your check engine light could be non-functional and covering up errors that the ECM has.
Check your fuel pressure.
Connect my scan cable (I know shameless self plug) and see what your ECM says it is receiving for IAT (Intake Air Temp, aka MAT Manifold Air Temp) and CTS (Coolant Temp Sensor) and make sure they are reading right.
Update: after driving around for a couple of days, it also seems to have a slight miss. It has plenty of power, but hesitates when you get into it. I'm thinking this is also because of the CTS. Am I right?
[This message has been edited by PatrickTRoof (edited 02-12-2014).]
Update: Last night I parked it in my friend's garage and picked up my '91 Volvo 240 wagon in anticipation of the arctic apocalypse we're about to get. Anyway, I filled the Fiero up with high test and parked it. Today I started it cold - one crank - and gave it gas. It did a lot better. Still a miss, but it didn't fall flat on its face. I let it warm up at idle while I worked on the Volvo, and it settled down to a normal idle. I did check the codes and it was giving me 32 and 35. I think my IAC plug is loose. This also lends weight to the fuel pressure issue. I need to get a test gauge that fits. Stay tuned.
Update: I checked the timing in ALDL mode, and it was waaay retarded. I could have sworn I had meticulously set that already! Anyway, I set it to 10* advance and tightened it down again. I went for a drive and it was better, but still some missing, especially in third gear. It bogged down and I floored it, and it slowly wound up.
Also, it just occurred to me that it needs a ground strap from the block to the chassis. I'm sure that could be playing hell with the electrical system.
Update: I pulled off the distributor in order to put a new gasket on it (leaking oil), and noticed that the vanes were all rusted and the pickup coil was in bad shape. So I swapped in a better spare distributor with an almost-new (never used) pickup coil, drove to the auto parts store and got a new cap and rotor. It was still running really crappy, and would stall at idle, and I was getting really frustrated. When I got home I ran it in diagnostic mode, and it cleared right up! Settled down to a nice, smooth idle with a gentle lope between 900 and 1100 rpm. It has plenty of power now, and I can lug it right down to idle speed in 4th gear and bring it back up by gently giving it gas.
)! I've been trying to find this device.
