Recently my 98 Cobra convert. has become very hard starting and has poor idle quailty. It will start and idle @ 900rpm, but soon after it develops a dead miss, and the idle falls off to around 400rpm and it will struggle to stay running. It clears out and runs ok after 2000rpm or so, but will always try to die as it idles down. It has a new fuel pump, filter, fuel lines, and an adj. fuel pressure regulator set at 40psi at idle. The car has about 95000mi. on it, and has fairly new denso irridium plugs. Other than that, it is bone stock. I am thinking that I may have a bad injector, but I am tired of throwing money at it. Any ideas? This is getting old quick.
Does it have any codes stored? It doesn't necessarily need to trigger a check engine light to have some present. If any sensors are still reading within the operating parameters in the computer, but incorrect for the current operating conditions, they won't trigger the CEL.
As a matter of fact it stored 6 codes. PO175 - Too Rich Bank 2; PO172 - Too Rich Bank 1; PO308 - #8 cyl misfire; P1131 - Lack of HO2s Bank 1 indicating lean; P1152 - Lack of HO2s Bank 2 indicating Rich; and the famous P1516 - IMRC input error. Quite a list considering I was unaware of any stored codes. The P1131 is puzzleing, but the rest would seem to indicate that I have too much fuel pressure. 40lbs should be right in the ballpark I would think, but maybe my gauge is off. What do you think? By the way, I cleaned the maf sensor wire with sea foam and a q-tip after I started having this trouble and didn't notice any change. I still wonder about injectors.
Well, I turned the fuel pressure down to 32lbs; cleared the codes, and the engine now idles fine, but it is still hard starting after it warms up. It starts right up when it is cold, first thing in the morning, but after it is up to operating temp. it cranks for a long time before it starts, and then it smells flooded, smokes black, and stumbles until it clears out the excess fuel. The good news is, no new codes stored. Could my injectors be leaking down, or..................what? Help me out here, surely somebody has had to of had a similar problem.
My 03 cobra was doing all of those codes.ended up being a bad valve.pull all plugs and look for a wet plug.
