85 cougar turbo low miles, misfire w\ boost +

Topic: 85 cougar turbo low miles, misfire w\ boost + (Read 2266 times) previous topic - next topic

85 cougar turbo low miles, misfire w\ boost +

September 10, 2005, 06:54:07 PM

I just bought a 85 cougar xr-7 with a 4 cyl. turbo and a 5 speed manual. the car only has 8000 miles on it. when i got the car home i put a new fuel pump on it and drained the gas which had been there for at least 5 years. the car idles perfectly but when accelerating past 3k rpm i'm getting a terrible hesitation it seems to follow my turbo boost gauge, the more boost the more it hesitates. i have replaced the fuel filter and cleaned the injectors. any comments or suggestions would be helpful.

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #1 – September 10, 2005, 10:04:44 PM

EIGHT THOUSAND MILES??? WHERE DID YOU FIND THAT???

You may have to flush the fuel lines (including the fuel rail and pressure regulator) - the fuel may have crystalized in there and plugged your filter and injectors again. Ya might wanna check the plugs as well, and pull the distributor cap to look for corroded contacts and even corroded advance mechannisms & stuff.

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #2 – September 11, 2005, 01:27:50 AM

A good tune up may be in order, as well as possibly having the injectors cleaned.

An 8000-mile car is nice....but if it's been sitting for any length of time, it's going to need a once over.

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #3 – September 11, 2005, 08:59:02 AM

I took the fuel rail completely out of the car and inspected and cleaned it. I also removed the injectors and pressure cleaned them as well as making sure that the solenoids were working properly. I even went as far as replacing the plugs, cap and rotor. The car runs great until the turbo kicks in. At about 5psi of boost it starts to miss, as soon as the boost backs off the hesitation dissapears. Does anyone know if there is a sensor in there that tells the fuel to increase to match the extra air put into the engine by the turbo?

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #4 – September 11, 2005, 10:20:02 AM

Just the fuel pressure regulator, AFAIK

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #5 – September 11, 2005, 11:40:27 PM

What kind of spark plugs did you use? Gap?

The f/p is just controlled by the FPR and the boost signal from the intake.

You don't have a vac hose connected to the BAP sensor do you? (on the pass strut tower..about 2"x3"...black with an electrical connector). No vac hose is supposed to be hooked to it.

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #6 – September 12, 2005, 11:38:36 AM

Is the FPR mounted directly on the fuel rail? does it have a vacume line attached to it? I purchased the car two weeks ago from a friend of mine whom I've worked with for twelve years. He always talked about his cougar he had in storage with only 8k miles and had never seen rain. I couldn't understand not driving a car like that and never thought I'd be interestedin it. He asked me to list it on ebay for him and when I went to take pics of it I joking made him an offer and he surpisingly exepted. The car truely looks new in every way.

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #7 – September 12, 2005, 01:12:01 PM

Yes, the FPR is on the rail and has a vac line to it.

What type of plugs and gap?

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #8 – September 13, 2005, 09:30:46 AM

I replaced the FPR yesterday evening. No change. The plugs are original and look great but I'm out of ideas so they'll be replaced tonight.

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #9 – September 13, 2005, 09:41:42 AM

gap then at no more than .035"..you might even err towards .030" with stock electronics.

You also might check your wires...there is a possibility they might be arcing under the load.

They haven't seen many miles, but age isn't good for them either. Especially when they are to be used in a higher demand (forced induction) situaton.

Another thing to check. The rubber convoluted hose between the air meter and the turbo. Squeeze it and make sure it doesn't compress easily. They have a coiled wire support inside that keeps them from collapsing under boost (ie when the turbo is sucking more air). Also, do a good inspection of the rubber hose from the turbo to the intake....even a small split can be forced open under boost and cause issues.

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #10 – September 13, 2005, 12:58:22 PM

Hey thanks Chuck W I'll change the plugs and wires this evening and let you know tomorrow what happens.

p.s. I'm a huge holy grail fan....

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #11 – September 13, 2005, 02:02:45 PM

Quote from: Chuck W

gap then at no more than .035"..you might even err towards .030" with stock electronics.QUOTE]

does this go for the 88TC as well?

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #12 – September 13, 2005, 02:09:07 PM

Quote from: 88turbo

Quote from: Chuck W
gap then at no more than .035"..you might even err towards .030" with stock electronics.

does this go for the 88TC as well?

Yeah. You don't want to gap them too wide. Some guys even pull them down to almost .025", but I don't like doing that. Pulling the gaps really small is a sign of a weak ignition.

I think stock is .028-.032"

I was running .040"+ on the turbo Ranger with the DIS coilpack...much hotter spark.

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #13 – September 13, 2005, 03:00:14 PM

pics! hehe.. where are the pics!!!

and i didn't notice chuck W's sig either.. i do so love that movie.

Re: 85 cougar turbo low miles, misfire w\ boost +

Reply #14 – September 13, 2005, 11:48:20 PM

I think I have the same problem as wi002ri. mine misfires and sometimes has no throttle response. could the dist. timing be off a bit?