85 SVO runs terrible

[ctemp100]

85 svo/65k mi. Chaged to PE computer,35# injectors,& TC innercooler. Ran great on 10 minute test drive. Went to restart,it would fire & die. Ran bad at higher rpm also. We have flip-flopped parts from 86 svo including; IAC,TPS,TFI,Distributor, & a 2nd set of injectors(1 was leaking by).Fuel pressure is 34# @idle & up to 45# at high rpm. Was running rich with black smoke with leaking injector,but not anymore. Finally kept it running long enough to warm engine & could drive car,but rough idle. let cool over night & same old problem. Any help would be appreciated. Jeff

[svobud]

go back to the basics .... are you sure you didn't melt a spark plug wire? How bout your plugs? How bout checking to make sure you don't have a leak from one of your IC hoses ... checked timing? what about the timing belt? could it have slipped?

[GAboySVO]

Did you add an Air Temp sensor to the intake? If you didn't, that is your problem. Take a look at the '86 lower intake in the center. That is the Air temp sensor. The "Air temperature sensor feeds information to your computer to maintain optimum performance."

I don't think the 85s had this sensor.

[Tony]

I don't think it's an air temp sensor. The 86 manifold does not have the ACT (Air Charge Temp.) sensor. None of the SVOs did. the lower manifold has a coolant temp sensor between the #2-3 runners, a fan switch sensor underneath in the center, and a knock sensor pointing toward the firewall. It has the boss for the ACT, but it is not drilled/tapped for the sensor. The PE does not require an ACT sensor.

As for your problem, Bud's right on the money... Check the basics first. Also, look for vacuum leaks. Sounds like a loose intercooler hose connection or the like. Make sure all the hose clamps are secure and straight between the air cleaner and the throttle body. Also, did you say you swapped the IAC, TPS and distributor? Do you know the history of all these parts? Check for ~.95vdc on your TPS all the way closed, also look for dead spots all the way up to <=5.0vdc. Another thing you will want to consider is the TFI module on the side of the distributor. If those 2 things aren't new, (TPS and TFI) and you don't know how old they are, you may want to replace them on general principal anyway. They are both known problem areas of this motor and should be replaced periodically as general maintainence items. Both have caused similar symptoms in my 85 and the TFI has left me stranded. Good luck and please let us know what it was when you find it so that we can all learn from your experience.

Tony

[ctemp100]

Last night we got the car warmed up & we reset the base idle & adjusted the TPS. Car ran,but very rich. We've already replaced the distributer & TFI. This morning same old story. Today I replaced the VAM with new. Car started & ran at idle. Replaced plugs(2nd set) & O2 sensor. Now at the start of boost & high boost, falls on it's face. Get it to 6-8# of boost & it settles out. I wanted an SVO since 84 & got this 3 months ago. I'm starting to wonder why I ever wanted one.(I actually have 2 now. WHY ME?)

[SVOeric]

how about the spring that is in the hose between the vam, and turbo...

if there isn't a spring in there, or if it is all bunched to one end, that thing will collapse, and it will feel like you stomped the brakes!

[GAboySVO]

Tony

I think you need to double check your facts. My '86 has an air temp sensor. The ECT is on the back side of the manifold down near the crank casr ventilation canister.

Here is a picture of it:

[GAboySVO]

Tony

Both the above sensor and the one below are installed on my '86

Here is a picture of the ECT:

[SVOeric]

no Mike -- he is right---

there is a air-temp sensor on a 86, but it is in the VAM

there is not a air temp sensor anywhere on the intakes of a 86 SVO.

[svobud]

FWIW, when I installed the LA3 EEC in my early 85 .. I didn't make any concessions for an Air Temp sensor as Ryan pointed out as well, it's in the VAM. 4 wires were switched out on the EEC plug harness, installed 35# inj . and that's it. My car runs great. Idles fine. IOW, no side effects.

[svobud]

BTW, I still think ctemp100 needs to back up and regroup. Swapping out pieces and parts randomly is not going to solve his problem quickly.

Check the plugs (gap and BRAND)
Check the wires (for burn spots and BRAND)
Check Timing.
Check IC hoses.
Check for Vaccum Leak.

[Majestic]

Jeff,

Sorry to hear about the problems with the 85. Since that used to be one of mine, and I've done the PE/brown top/TC IC swap about 10 times, I'm going to say that there is something else (probably simple) wrong.

First thing I would check is the ground strap connector to the turbo. Should be a brownish-tan wire that connects to the front of the turbo. If it is loose or disconnected, it can cause problems like you describe.

Next, check your coil to make sure you're getting enough spark. I know that you've been told this 3 times already, but the plugs and wires make a giant difference on these cars. Some NGK's and FOMOCO wires should rule out these areas as the problem.

Also, you DO HAVE THE stock boost controller disconnected, right? If not, do so at once or you are going to toast your new PE. Get a Gillis valve or similiar and disconnect the knock sensor while you're at it.

Good luck and keep us updated.

Chris

[svobud]

Originally posted by Majestic


Also, you DO HAVE THE stock boost controller disconnected, right? If not, do so at once or you are going to toast your new PE. Get a Gillis valve or similiar and disconnect the knock sensor while you're at it.

Holy crap .. I didn't even think about this. He's still using the stock Boost Control Silenoid from a early 85? I just assumed that if he was doing a EEC/injector swap - he would have already ditched the BCS a long time ago.

[Majestic]

Yeah, some of the simple things get overlooked. I hope he gets that one straightened out. That was one of the fastest stock 84-85 SVO's that I ever owned. It ran dead even with my friend's slightly modded (K&N and 18 lbs. boost) 1986. Really just needed some exterior work.

[ctemp100]

Disconnected BCS & control when I installed PE. Spring in turbo inlet hose is just fine. Plugs are Motorcraft & gapped at.030. The guy helping me with this has had several of these cars & is a mechanic (formally for Ford). This car has him stumped. I'm starting to think this is a case of fix the weakest link to find the next weak link. I went out for another test drive & the rt front caliper is now stuck. All of my service trucks are Ford w/160-300K on them. Maybe at 65K this car isn't good & broke in yet. By the way, my 84 w140k is for sale. I will post it when I get my brain restarted.Jeff