Ok guys here is an interesting one that you pros maybe be able to help me(newbee)with. I have an 87 GN with 120K on the clock. New plugs and the spring cleaniing complete. The car will fire right up when it is cool, however, after it is warm or on a hot day it will crank for 10-15sec before firing. It kind lopes until computer raises idle to 2k or so then idles back down. By the way it is all stock.
Thanks,
Aaron
no check engine light? Did you check fuel filter/pump/fuel rail pressure with a fuel pressure gauge?
No check engine light. The MAF was bad and bought a reman. That is the only thing that I have changed on it. I have not checked the fuel pressure. I will do that. The car had been sitting for about five years and is now being brought back from the dead. I have changed the fuel and filterand run about three tanks of fuel out of it. You know it might be the fuel pressure because if I give it alittle press on the gas pedal it starts faster. Let me know if anything else comes to mind. Thanks
After sitting for five years I would change and upgrade the fuel pump, regulator and injectors. Keep in mind that about half the remanned MAF's out there are worthless on these cars.
Oh ya, SCAN TOOL, SCAN TOOL, SCAN TOOL!
I agree, it could still be the MAF. Disconnect it and see how its starts.
It might also be the IAC valve. The fact that you have to step on the accelerator leads me to believe that your idle screw is too far out and that the IAC can't bring the air into the plemnum fast enough for the car to idle properly. Have you removed it and checked to make sure the valve itself and the cavity that it sits in is clean? Try that and then try to reset it according to the website procedures. There is a way to do this w/o a scan tool.
If you think the injectors are clogged, there is an injector cleaner kit you can use right on the engine. 3M makes the chemical and then the "kit" that contains the fittings, etc. is borrowed or rented from the car parts store. If you have time, you can send them to Caspers Electronics and they will clean and flow check them. They're quick so the real time is in the shipping.
It is most likely your fuel pump.
Hey, does anyone have an answer for my question titled "Boost too low....?" Thanks. Norm
Hey guys, I am actually having the same problem here, The car will start right up when the engine is cold, but when its warm, its hard to start, and the warmer it is, the harder it is. I have a 87 GN, mostly stock, upgraded fuel system, Walboro 307 pump, hotwire kit, Plugs and wires are good, everything else pretty much original except exhaust.. only 35,000 miles on it. Fuel pressure is fine, it was at 41 vac off, and I set it down to 37, didnt make any difference. Sock is not collapsed, filter is good as far as I know.
No other complaints, Runs amazing, no hesitation, no power loss at wot.. Even tried different chip, was a stock, now a Trasher 92 octane chip. Any ideas guys??? Old fashioned way of thinking here, but almost seems like the fuel is getting so hot in the lines around the engine and fuel rail, that its causing this problem when engine is hot only. Also fuel rail holds pressure for over 20 mins.
If fuel psi. is OK when you turn ignition on, engine off, then it's obviously not the fuel pump or relay. Timing will usually cause this also. If cam setting is incorrect, it will cause a hesitation in starting and more so when hot. But, what I think is the problem is the module (coil/ignition module). From heat soak it will make the module perform in such a way that it will take a few seconds extra of cranking to start or not start at all if completely damaged. I hope this helps.
MARIO
CHECK YOUR STARTER FOR TOO MUCH AMP DRAW. MY CAR WAS SLOW TO START WHEN WARM, TOOK 12 TO 15 SECONDS TO FIRE UP THEN RAN OK. I PULLED THE STARTER & FOUND THE REAR BUSHING WAS WORN OUT, BRUSHES SHOT & WINDINGS W/INSULATION MELTED OFF. NEW STARTER SOLVED MY PROBLEM, CHECK IT OUT.