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88 Mustang GT- Running Terrible,Please Help!!!

Hello, Ive posted questions before and received great help.Here we go again. Vehicle:88 gt 5.0 with mass air conversion.bassani x pipe w/cats.hi flo cat back system,the rest is stock.

Here are the symptoms: Idle does not stay where it should.Idle is too low (550rpm).It only used to idle low until it warmed up,now idles low all the time.

Cruising at 2000 rpm the car will start to buck and jerk severely.I had to drive home in 35mph zone in 2nd gear just to drive it.

The smell coming from the exhaust is physically sickening.It is either running lean or rich,I don't know how to tell the difference.

Rattling sound coming from valvetrain while accelerating.I assume it is detonation.

Temp Gauge never gets past first line just above 130.I don't know if this a true reading or malfunctioning gauge.

Any help would be greatly appreciated. Bob

Reply to
5.0bob
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5.0bob Here are the symptoms:

You mean all that is happening and the check engine light is off, and no codes?

Start with getting the codes, check fuel pressure. Check all engine grounds and the BAP.

Check timing... make sure it's advancing and steady.

Reply to
Backyard Mechanic

I converted my old '88 PA car to MAF currently have a stock '88 VA car. '88 non-California cars didn't come with the MIL option. There's a spot on the dash but no bulb in it. I'd doubt that when the MAF conversion was done the OP put the bulb in to make it functional.

Yeah, there's some *serious* problems with that car. Ouch. Any mods other than the MAF conversion?

JS

Reply to
JS

Sounds like you are in "Limp In" mode. The CPU is inop and all the electronic gadgets are in their default state if so. It's real easy to blow the CPU when mess with the sensors, or try to dump the codes using the wrong procedure. (I did this twice to myself.)

"5.0bob >>" again.

Reply to
Ironrod

I don't think the Limp Mode was available that early. Someone correct me if I'm wrong.

Blue Gator

1989 LX 5.0

Reply to
Blue Gator
5.0bob,

I just changed over to mass air on an 88 Cougar motor that's in my son's

89 mustang. It would hardly run and wouldn't idle. Without going into too much discussion, its major symptom was that it was running rich. (It has no cats.) After severely beating my head against the ground and harassing everyone in here I found that it was the injectors. Appearantly it would run OK as a speed density but for some reason it wouldn't or couldn't as a mass air. I changed to new injectors and now it purrs.

DaveT

5.0bob Hello, Ive posted questions before and received great help.Here we go
Reply to
frog

Since I blowed up my 88's CPU twice I know from sad experience that it does have some version of it. All that happens is in lieu of the CPU telling the electronics to do otherwise they will always default to a condition where the car is still capable of running, poorly but still running. The timing is locked at 10 degrees, and the injectors are locked wide open are two of the things that happen.

Reply to
Ironrod

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