- Joined
- Jul 11, 2020
- Messages
- 213
- Reaction score
- 44
- Points
- 28
- Age
- 42
- Location
- Los Angeles
- Vehicle Year
- 1988
- Make / Model
- Ford Ranger
- Engine Type
- 2.9 V6
- Transmission
- Automatic
- 2WD / 4WD
- 2WD
Hi friends!
Playing whackamole with idle problems on my '88 XLT resto project. While I still have many knowledge gaps, I definitely appreciate everybody's wisdom here, as that has gotten me very far on this project.
TLDR question:
Can somebody explain to me why the truck is a shitshow in park and totally fine in gear?
Expanded question:
- 1988 2.9l XLT (Little Gold) has new cylinder heads, plugs, fuel pumps, IAC, TPS, MAP, distributor & wires, electric fan w temp switch, thermo, CTS, ICM, O2 sensor.
- After replacing inline fuel pump, truck always started first time and had good fuel pressure, but would take looooooong time to warm up and idle down to 850 rpm - if it ever got there. Once it would go under 1k, it would start missing and be generally fussy/unpleasant. Driving in gear was ok, def weak. MPG ok. Compression ok. OBD1 reader would show 11 (no codes/all good).
- Injectors, plugs, 02 sensor were last items to be upgraded, all at once. 2 injectors had bad o-rings, with one pintle cap long gone. When in D, idle is smooth. Power is great. Startup is a mess. Comes up to temp much quicker, idle falls from 2k, 1.5k, then gets to about 1.1k/1k, and then it stumbles and either stalls, or saves itself, bumps up to 1200 or so, then flirts with 1k rpm before quitting. Starts back up fine, gets into gear fine and is mostly problem free. The occasional misfire/stumble/wobble at a stop light but nothing serious. Doesn't stall. When put back in park, RPM goes all over the place. many misfire/stumbles. searching for right RPM range. it kinda smells like mothballs? I have not pulled codes or done compression test since replacing plugs & injectors.
MY FEARS:
- Did I crack a head while trying to dial in temp switch for electric fan? It was set too high, and saw coolant temp gauge get to the top of threshold before fan kicked in. N in normal. not beyond. Coolant level is fine/not falling. Oil level is fine/not falling. Don't see milkshake in oil, don't see oil in radiator or overflow. Tried glove test and didn't see any inflation/bubbles. have not pulled plugs to do compression test yet.
- I may have killed brake booster check valve? Pumping brake will elevate RPM in park. didnt notice this before replacing injectors. I may have inadvertently yanked too hard on it trying to get fuel rail out.
- Is intake gasket bad? Would a vacuum leak cause these kinds of problems in Park but not in drive?
- Could ICM be bad? I have a replacement from a fat finger mistake, but haven't tested the one in the truck. Wouldn't that affect higher RPM range and not lower if it were bad?
To anyone who has wisdom or thoughts, would love to hear it. Thanks everybody!
Playing whackamole with idle problems on my '88 XLT resto project. While I still have many knowledge gaps, I definitely appreciate everybody's wisdom here, as that has gotten me very far on this project.
TLDR question:
Can somebody explain to me why the truck is a shitshow in park and totally fine in gear?
Expanded question:
- 1988 2.9l XLT (Little Gold) has new cylinder heads, plugs, fuel pumps, IAC, TPS, MAP, distributor & wires, electric fan w temp switch, thermo, CTS, ICM, O2 sensor.
- After replacing inline fuel pump, truck always started first time and had good fuel pressure, but would take looooooong time to warm up and idle down to 850 rpm - if it ever got there. Once it would go under 1k, it would start missing and be generally fussy/unpleasant. Driving in gear was ok, def weak. MPG ok. Compression ok. OBD1 reader would show 11 (no codes/all good).
- Injectors, plugs, 02 sensor were last items to be upgraded, all at once. 2 injectors had bad o-rings, with one pintle cap long gone. When in D, idle is smooth. Power is great. Startup is a mess. Comes up to temp much quicker, idle falls from 2k, 1.5k, then gets to about 1.1k/1k, and then it stumbles and either stalls, or saves itself, bumps up to 1200 or so, then flirts with 1k rpm before quitting. Starts back up fine, gets into gear fine and is mostly problem free. The occasional misfire/stumble/wobble at a stop light but nothing serious. Doesn't stall. When put back in park, RPM goes all over the place. many misfire/stumbles. searching for right RPM range. it kinda smells like mothballs? I have not pulled codes or done compression test since replacing plugs & injectors.
MY FEARS:
- Did I crack a head while trying to dial in temp switch for electric fan? It was set too high, and saw coolant temp gauge get to the top of threshold before fan kicked in. N in normal. not beyond. Coolant level is fine/not falling. Oil level is fine/not falling. Don't see milkshake in oil, don't see oil in radiator or overflow. Tried glove test and didn't see any inflation/bubbles. have not pulled plugs to do compression test yet.
- I may have killed brake booster check valve? Pumping brake will elevate RPM in park. didnt notice this before replacing injectors. I may have inadvertently yanked too hard on it trying to get fuel rail out.
- Is intake gasket bad? Would a vacuum leak cause these kinds of problems in Park but not in drive?
- Could ICM be bad? I have a replacement from a fat finger mistake, but haven't tested the one in the truck. Wouldn't that affect higher RPM range and not lower if it were bad?
To anyone who has wisdom or thoughts, would love to hear it. Thanks everybody!