dumb question here but,

are you fuel injection or carborated?

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96 F150 XL,special
Air/PS/PB/AM-FM-Cass/
Light Package/300 I6/
5 SP Man/...
Nothing fancy just my little baby

[This message has been edited by jimbello (edited 08-25-2000).]

 

he said "87 f150 302 EFI" that's electronic fuel injection. I'm no mechanic but was this
problem happening before you replaced the temp sensor? If this was a carburated engine I'd say the choke was not open for cold starts. In a EFI engine this is accomplished by the computer reading engine temp through the temp sensor(I think?) maybe the temp sensor you installed is bad or a connection wiring problem with its plug. You'll need a more experienced mechanic than myself to tell you how to prob the plug and wires to tell you if the plug/wiring is good. They could also tell you how to test the sensor to see if that is good. I think I would investigate that "wiring harness modification" you mentioned. If you could give us a description about what you mean by "Moditications" we might be able to puzzle something out.

Hobbit

Answers? Free.
Right Answers? Priceless. (But not guarenteed)

 

I have a 87 F-150 302 EFI that has developed a cold start problem. I have replaced plugs,cap,wires,rotor,coil, recently, fuel pump 1yr. ago also coolant temp sensor(computer) recently. After extended cranking it starts when cold , but when warm it starts no problem, any ideas? Also I noticed some wire harness modifications done near the ecm test connector were these done by the previous owner or from a TSB ? any help would be appreciated. Thanks in advance

 

I replaced the temp sensor after the cold-start problem came up. I think I'll try the fuel filter it's overdue for a change anyway . As far as the harness mods they are made on the top of the drivers side front fender there is a bracket that supports a plastic cover that holds two devices (relays ??) as they are solid state, anyway a couple of wires have been cut,spiced with a scotch connector and one has ring terminal put on it to a ground. I've never had trouble with this before. The mod appears to be made from a TSB but, who knows, previous owner is not an option. Thanks for any advice it's appreciated ,Steve

 

Sorry bout that, Missed the "EFI" in his original post.They say the eyes are one of the first to go.
I saw in the last post that some mods were done to the wiring or something like that. Check em all if you can. These 12V systems are very touchy when connections start to corrode.

Dam I miss the old days when ya used to stick a pencil in the carb to hold the butterfly open.


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96 F150 XL,special
Air/PS/PB/AM-FM-Cass/
Light Package/300 I6/
5 SP Man/...
Nothing fancy just my little baby

 

I would still make sure the plug and the wiring is to that temp sensor is good with a multi-meter before you rule it out completely. I have had sensor related problems before when it was the wiring or plug that was bad not the sensor.

As far as the wiring mod, do you have any accessories like fog lights, etc. Can you trace the wires to their end or do they just go into those relays you mentioned. My thought is they may be an add on for something, are the relays powered from the battery? I can't see a dealer making a wiring change like you describe.
Hobbit

 

Check the air bypass valve on the side of the throttle body.If it is clean check to see if the solinoid is working.

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97 F150 Flareside Ext Cab
XLT,4.6 Auto,DK Toreador Red,Ford Signature Atlas rims
275/60 17 Yokohama AVS
3:73 LS,K&N Fipk
Superchip,Flowmaster Force II,Ford 9mm wires
Bosch Platinium +4


[This message has been edited by DG13 (edited 08-28-2000).]

 

I did a little more checking the mods have been made to the wiring harness at the fuel pump relay and eem relay even if they are wrong I've had the truck for 3yrs without any starting problems before. The truck has passed emissions with these mods there are no accesories added . I was just curious what they were. As to the starting problem I'm just about tapped out.(getting close to taking it in) Thanks for all your help.

 

I had a 1990 F250 that exhibited some
of the same issue listed in your post.

What i found to be the problem is there
a module on the front of the distributor
cap that controls the fuel and spark.

Scott

 

I've been doing a lot of research since I last wrote it seems that the computer is bad/and has been bad for a while(before I got the truck) the wiring mods have been made to the fuel pump relay wires it seems that the computer wouldn't allow the pump to start so the *#??%% previous owner jumped the relay to ground,so it still works off the key it just doesn't get any commands from the computer any longer. It also appears that the gasket that seals the computer connector to the firewall has been leaking(rain water) for a while as the alum. heat-sink is corroded and probably corroded inside as well(that would explain why I have been unable to flash-out any trouble codes) has any one heard of this one before ? Where can I get the computer tested (off the truck if possible) before replacing it? Any one have any suggestions??
Thanks, Steve

[This message has been edited by Chubet (edited 08-30-2000).]

 

Just a follow-up, in addition to all the replaced ignition parts I replaced the module on the distributor, while I was in there I noticed that the recently replaced cap and rotor were arced and worn like they were years old (resistance in the cicuit?)has anyone heard of this before ? any ideas would be appreciated, Thanks in advance