FordeatinZ71
01-02-2012, 11:45 AM
so lately i've been working on my great grandpa's old '87 F150 getting ready to daily drive it again. it really is a good old truck, it's been in the family since 1993 and i can count on one hand (and not use all my fingers) the times it's been broken down/in the shop. it has the EFI 4.9 (300 cu. in.) inline 6 and the 4-speed manual with OD. it's a RCLB 2wd XL (it's the one in my sig next to the '98). i got it about a year ago and daily drove it for a while, then my dad got into this horrible deal for the '98 i have now (i took over payments fora bit, giving it back in a few weeks #notmyproblem) so he drove the Ford for a while...now i helped him get his '01 Silverado (should have gotten for myself) and now that it's running, the Ford is getting some repairs to get her ready to be my daily driver again...
the main issue i'm trying to conquer is a bad surging idle. it will surge from 500-1000 RPM constantly while idling. before i got it from my uncles, a shop i don't trust put in a new high pressure fuel pump (on the frame rail) and replaced the rear in-tank pump. they also put in 6 new injectors it didn't need to jack the bill up. also new plugs/wires. i got it, and the first things i did to try to fix the surging idle was to replace the IAC valve and the TPS. still no change. i pretty much just dealt with it after that.
fast forward to today, i've decided i'm gonna jump on this problem again...i thought my brake booster might have been leaking so i plugged off the vacuum hose going to it...no change. i was letting it run and i found out that it actually stops surging if you hold the brake down...it goes to about 900-950 RPM (a little high, yes) but is rock solid. release the brake, and the surge comes back. but plugging (heheh, i said butt plug) the booster off doesn't change it. i went to check codes (really stupid setup Ford has on these trucks) and found out i had no light. so i pulled the dash bezel and i really HAD NO LIGHT. i guess it was one of Ford's "better ideas" to make a computer controlled truck with no check engine light. so to check the codes, i attached my test light to the check engine ground port of the self-test connector under the hood.
found my codes:
23-TPS out of self-test range (guess the new one is bad...)
67-Neutral Drive Switch open or A/C or defrost on during test (operator error) (not sure on this one...my A/C doesn't even have a compressor right now and the controls were all off...i guess because i wasn't hitting the clutch the switch was open and not closed?)
95-Fuel Pump circuit open, EEC processor to motor ground (fuel pump unhooked or wiring damage) (gonnahave to check into this one...like i said, i didn't trust the shop it went to...they had it almost 3 months for friggin fuel pumps...
so now i'm waiting on the guys on the F*rd message board to help me out, i'm like a fish out of water working on these older Fords...i miss GM already and mine's not even gone yet. although i will say this...that 300 I6 blows that 262 Vortec out of the water when it comes to low/mid range power. if it had the gearing it'd probably give it a run up top too...
the main issue i'm trying to conquer is a bad surging idle. it will surge from 500-1000 RPM constantly while idling. before i got it from my uncles, a shop i don't trust put in a new high pressure fuel pump (on the frame rail) and replaced the rear in-tank pump. they also put in 6 new injectors it didn't need to jack the bill up. also new plugs/wires. i got it, and the first things i did to try to fix the surging idle was to replace the IAC valve and the TPS. still no change. i pretty much just dealt with it after that.
fast forward to today, i've decided i'm gonna jump on this problem again...i thought my brake booster might have been leaking so i plugged off the vacuum hose going to it...no change. i was letting it run and i found out that it actually stops surging if you hold the brake down...it goes to about 900-950 RPM (a little high, yes) but is rock solid. release the brake, and the surge comes back. but plugging (heheh, i said butt plug) the booster off doesn't change it. i went to check codes (really stupid setup Ford has on these trucks) and found out i had no light. so i pulled the dash bezel and i really HAD NO LIGHT. i guess it was one of Ford's "better ideas" to make a computer controlled truck with no check engine light. so to check the codes, i attached my test light to the check engine ground port of the self-test connector under the hood.
found my codes:
23-TPS out of self-test range (guess the new one is bad...)
67-Neutral Drive Switch open or A/C or defrost on during test (operator error) (not sure on this one...my A/C doesn't even have a compressor right now and the controls were all off...i guess because i wasn't hitting the clutch the switch was open and not closed?)
95-Fuel Pump circuit open, EEC processor to motor ground (fuel pump unhooked or wiring damage) (gonnahave to check into this one...like i said, i didn't trust the shop it went to...they had it almost 3 months for friggin fuel pumps...
so now i'm waiting on the guys on the F*rd message board to help me out, i'm like a fish out of water working on these older Fords...i miss GM already and mine's not even gone yet. although i will say this...that 300 I6 blows that 262 Vortec out of the water when it comes to low/mid range power. if it had the gearing it'd probably give it a run up top too...