'87 Colony Park, stutters, bucks, and stalls. Help Pls!

[jeff97062]

I picked up an 87 Colony Park wagon with a 302 in it. It stalled a LOT for awhile, but I figured I'd get it sorted. Well, it's better, but only by a very little bit. I've spent 5 times what I paid for the vehicle letting a mechanic try to solve my issues. All to no avail. He fixed other stuff that probably needed fixing, but not the rough/stalling issue.

Symptoms:
- stalls at stop lights/signs
- stutters and stalls when put into gear (idles in park just fine)
- bucks when going up hills
What I've tried to fix it, unsuccessfully:
- replace fuel filter
- replaced fuel pump with electronic pump
- replaced fuel injectors
- replaced fuel injector wiring with new wiring harness
- replaced TFI
- replaced Dizzy
- Replaced sparkplug wiring
- Replaced ECU
- Bypassed SMOG diverter
- Replaced fuel regulator
- Replaced idle air control
- smoke tested and fixed all leaking hoses that I could find

Next steps I'm considering:
- check spark with spark tester
- check ignition to see if fuel is at constant PSI, even when stalls
- Run new wire to fuel injector and ground properly (since old wire may be faulty)
- Beat my head against the wall mercilessly....if nothing works

I'm really at my wits end with this thing. Any help/suggestions GREATLY appreciated.

[FordMan77]

Dumb question, but when the distributor was replaced was it re-timed properly? Should be set with the SPOUT connector disconnected and at 10* before TDC iirc. Did you use an OEM Ford TFI module or aftermarket?

[jeff97062]

I think so. My mechanic did it. The TFI is after market

[Arquemann]

Check TPS and EGR, bad spots in the TPS sweep or out of calibration. EGR valve might be full of crap and hanging open.

http://www.grandmarq.net/oldfuelinjection/page30.html

[Tiggie]

In addition to the above, I don't see spark plugs on your list. I'd replace those if they haven't been replaced. Get the copper ones, usually the cheaper choice at the parts store. Easy to do yourself if you have a few hand tools.

I'd also check to see that the base idle is correct. https://www.muscularmustangs.com/idlereset.php

There are some other idle troubleshooting tips on that website as well.

[jeff97062]

Thanks Fordman!

[jeff97062]

Thanks Tiggie! Will try all this and report back!

[WagonMan]

How many miles on the engine? Timing chain been replaced? WagonMan

[friskyfrankie]

May or may not matter but I wouldn't trust an aftermarket TFI. May be difficult to find an OEM but I would make to effort to do so.

[jaywish]

How does it run when not trying to idle?

[friskyfrankie]

Actually, Rockauto shows it for an '87 GM which is the same part for about $86 (MOTORCRAFT DY1284 {DU2Z12A297A} should you decide to go that way. Haven't looked at EBAY to see if the price can be beaten or anywhere else, for the matter.

[TheEnglishChap]

I too have an 87 CP. So here is some thoughts (if you have not done these already).
For the plenum on the upper intake manifold and throttle body gaskets, as well as fuel pump o-ring, I used aviation grease (not sure of the motor-world name) to help with the seals. This certainly solved my high-idle (turns out I had not greased the new IAC gasket and it compressed to the point of allowing air to sneak by it in one spot).
If not greased, you may have to get new gaskets, plenum, etc...

[gadget73]

1987 specifically sometimes had the old crappy single row timing chain. Would be worth checking that for slop. Only practical way of doing that without opening the engine is to remove the distributor cap and put a breaker bar on the crank. Rock the crank and note how far it turns before the rotor follows. A tight chain will be minimal movement, a sloppy one will have significant travel. If its loose enough it can give you erratic spark timing, and since fuel injector pulse comes from your ignition pickup, it makes that flaky too.


ever scan it for codes? Sometimes that will give a lot of insight.

honestly sounds like someone loaded up the parts cannon and just threw things at it. Some of that stuff may have needed replacing but the injector harness is not a typical fail item. Neither is the ECM. These things aren't that complicated, but they also don't have a lot in the way of self-diagnostics so it takes some obsolete knowledge (or the factory shop manual) to figure it out.

[jeff97062]

May be a good call TheEnglishChap. I put the idle air control in with no grease. I'll try that, along with the base idle check suggested by Tiggie.

[jeff97062]

Not sure on mileage. It rolled once or twice at 99,999,999. It say 44,XXX,XXX now. So could be 144 or 244. My guess is 144,xxx,xxx