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Looking for suggestions. Is it normal to push down on the accelerator to get motor to start when engine is cool. I believe I may have issue with the cold start valve. Any suggestions on how to confirm this?
I don't touch the accelerator pedal at all when I start, hot or cold, either of my 85's or any of my fuel injected vehicles no matter the year. Not 100% sure but I don't believe an 87 has a cold start valve or injector (what an 85 has). Not sure if I helped you. I'm sure someone more knowledgeable about the 87's will chime in.
87 cold start valve is on drivers side between intake manifold runners for cyl's 3 & 5 on drivers side and the switch I believe is in front near coolant temp sensor. Have you checked fuel pressure ?
Any codes? How does is run once it is started? Do you have 2 seconds of fuel pump when key is turned to first position (Run) ?
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I checked the fuel pressure awhile ago, it was around 36 psi with key turned on. I do recall the pressure dropping off fairly fast after turning key off. I wonder if that is the start problem. Car runs fine once it’s running.
From: Liliha Bakery stuffing my face with coco puffs!
36 psi is what it should be while the engine is running. With the vacuum line removed and capped engine running, it should be at 43 psi. With key on engine off, the ECM energizes the fuel pump for 2 seconds. With that said, make sure with the KOEO test you observe the fuel pressure on the gauge within the 2 seconds of prime and it should read 43 psi.
36 psi is what it should be while the engine is running. With the vacuum line removed and capped engine running, it should be at 43 psi. With key on engine off, the ECM energizes the fuel pump for 2 seconds. With that said, make sure with the KOEO test you observe the fuel pressure on the gauge within the 2 seconds of prime and it should read 43 psi.
Everything checked out good. 43 psi after the two second prime. So I’ve been playing it with it, with the cold start valve disconnected the engine fires off rapidly on first start of day however then on restarts I’m back to pressing on accelerator to get it to start faster. It appears the cold start valve is over flooding the engine on the first cold start up but then the opposite is happening with it disconnected on starting where the engine is relatively warm.
Mine also, but mine is more likely the 35 year old fuel injectors. Easy to start cold, Easy to start hot, but in between is difficult. I have the, fuel pressure regulator, IAC, EGR valve, MAT, injectors, gaskets, CTS and lot more ready for the day this great weather changes.
1. Did the 43 psi remain on the gauge ? for how long ? Key on, key off, what is the psi for the next few minutes?
You mentioned in your first post "when the engine is cool", Is that the first start of the day?
Mine also, but mine is more likely the 35 year old fuel injectors. Easy to start cold, Easy to start hot, but in between is difficult. I have the IAC, EGR valve, MAT, injectors, gaskets, CTS and lot more ready for the day this great weather changes.
1. Did the 43 psi remain on the gauge ? for how long ? Key on, key off, what is the psi for the next few minutes?
You mentioned in your first post "when the engine is cool", Is that the first start of the day?
ARE there any codes ????????????????
YES… It held 43 psi for at least 15 minutes after turning key off. Then it only dropped a few psi. Overnight it was down to about 12-15 psi and came right back up to 43 psi when turning key back on. YES to your question on cool engine (first start of day). No codes… I suspect you may be right about 36 year old injectors even though the car only has 14K miles on it.
Hard cold starting on 1987 C4
