1988 d100 318 tbi.truck runs perfect. It’s just a long cranking. Any ideas why??????
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1988 d100 318 tbi.truck runs perfect. It’s just a long cranking. Any ideas why??????
So the truck runs perfect no hesitation very smooth. When you floor it has a great pick up. When you’re at a red light you can barely feel it running. Only Problem is the engine takes several revolutions each morning and most of the time when you go to start it. My buddies at work always laugh and tell me it’s a good thing you have a strong battery. when we leave lol. I am wondering if the throttle-body is supposed to inject two squirts of gas as you turn the key to the starting position?
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From: Clayton MI
PCM will enrich fuel while cranking. It shouldn't shoot any unless it actually sees the engine turning.
If you cycle the key a couple times, so the fuel pump primes twice or thrice, will it fire right up then?
If you cycle the key a couple times, so the fuel pump primes twice or thrice, will it fire right up then?
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How old are your ignition parts? Get good spark to the plugs?
I might be tempted to go thru the hassle of actually checking fuel pressure on that one.....
I might be tempted to go thru the hassle of actually checking fuel pressure on that one.....
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They are all newer. I did replace the coolant temp sensor. I have tried different injectiors. I also installed a new ECM and asd. When I first got the truck. I had no spark. so I went through all that stuff.and now I have this issue. truck only has 58,000 original miles on it. I also have a 89 w150 315,000 miles on it. It starts before I let go of the keyswitch . Sorry for the long reply.
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They are all newer. I did replace the coolant temp sensor. I have tried different injectiors. I also installed a new ECM and asd. When I first got the truck. I had no spark. so I went through all that stuff.and now I have this issue. truck only has 58,000 original miles on it. I also have a 89 w150 315,000 miles on it. It starts before I let go of the keyswitch . Sorry for the long reply.
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where are you testing fuel pressure? i am pretty sure you should be seeing higher readings than that. 14.5 is acceptable to run but the pump should probably be putting out 40-60psi and just returning what isn't needed. you probably shouldn't be loosing fuel pressure immediately. there is a good chance the check valve in the pump has failed.
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All the mangoes I have read from 88 until 91 all have a 14 1/2 pressure rating
I believe you are thinking of the 92 and 93 dodge Magnum motors. When they went to Sequential port injection. I know they run a much higher fuel pressure rating. All the Manuels I have read from 88 until 91 all have a 14 1/2 pressure rating. I’m just not sure how long they are supposed to hold pressure in the off position.
where are you testing fuel pressure? i am pretty sure you should be seeing higher readings than that. 14.5 is acceptable to run but the pump should probably be putting out 40-60psi and just returning what isn't needed. you probably shouldn't be loosing fuel pressure immediately. there is a good chance the check valve in the pump has failed.
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i am not mixing things up. the output of the pump should be more than 14.5. it requires at least 14.5 to keep the TBI working but the pump should still be putting out more than that. the regulator on the TB returns what is not needed. i had a pump that was putting out 60-70psi hooked up to my 89. currently got that pump in my 81 for the fitech. if you have replaced the injectors and you are loosing pressure the moment you shut it off the check valve in the pump is bad or your regulator may be bad. you can try pinching off the return line to see if fuel pressure rises and pressure does not drop off immediately.
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So the truck runs perfect no hesitation very smooth. When you floor it has a great pick up. When you’re at a red light you can barely feel it running. Only Problem is the engine takes several revolutions each morning and most of the time when you go to start it. My buddies at work always laugh and tell me it’s a good thing you have a strong battery. when we leave lol. I am wondering if the throttle-body is supposed to inject two squirts of gas as you turn the key to the starting position?
Last edited by Sammys68charger; Mar 10, 2019 at 08:38 AM.
