OT: chevy 4cyl problems

TripleRange · Jan 2, 2009

1999 chevy caviler with 2.4L engine starts hard when hot. Pump the gas once, fires up...runs rough for 10-15 seconds...smooths out and runs fine the rest of the time. What's the cause?
No check engine light. 165,000 miles

happy hooker · Jan 2, 2009

Fuel presure regulator is most likely bad. On the fuel rail there will be a round part with a vac line on it. Put a vac pump on the regulator with a clear hose when the engine is hot and look for fuel being pulled into the clear hose.

Brian Jasper co. Ia · Jan 2, 2009

All you have to do to check for a leaking fuel pressure regulator is pull the vacuum hose off while running. If the diaphragm is leaking, it will be obvious.
Pumping the accelerator on a fuel injected engine before cranking has NO effect on starting. There is no accelerator pump. Pull the plugs out and look at them. I'll bet you find one or 2 with a bunch of white/off white crusty stuff on them indication a leaking head gasket. Quad 4's are known for head gasket trouble.

Brian Jasper co. Ia · Jan 2, 2009

One more thought, cycle the key on and off 3 or 4 times before cranking. If it starts easily and runs smoothly, fuel pump is probably getting weak.

bradk · Jan 2, 2009

Does it smoke black or white once started? Does it use coolant? Culprits are leaking injector(s),ruptured fuel press. regulator or head gasket.

Either fuel or coolant in the cylinder(s) is why you need to crack open the throttle while cranking.

El Toro · Jan 3, 2009

I had a similar problem on a Chevy Citation. It would just die going down the highway, but would restart after the car stopped moving. I installed a fuel gauge between the filter and TBI.
I noticed when you tried to accelerate on a hill the pressure dropped a lot. I always thought it was fuel problem so I dropped the fuel tank and found a lot of rust blocking the inlet to the pump. I cleaned out all the rust and I bought a new pump and installed it with a new sock over the inlet to the pump. That fixed the problem.
My neighbor was over watching me and said I wouldn't change that pump. I said you're not doing all this work that's involved. New pump was about $50.00 from Pep Boys. It also had a lifetime warranty. Hal

Kentb of SWMO · Jan 3, 2009

On EFI engine whether throttle body or port injection stepping on the gas pedal before starting does NOTHING. There IS NOT an accelerator pump like on a carburated engine.
My 89 239 Dakota v-6 ha s a throttle positioner that at engine shutdown open the throttle somr for the next start cycle. Do not know if your Chey has this.

Kent

OT: chevy 4cyl problems

TripleRange

Member

happy hooker

New User

Brian Jasper co. Ia

Well-known Member

Brian Jasper co. Ia

Well-known Member

bradk

Well-known Member

El Toro

Well-known Member

Kentb of SWMO

Well-known Member

Similar threads