I have come across another problem.

When I come to a stop especially out of 3rd or 4th it will just die while I'm slowing down. This happens while I'm holding the clutch and the brake down. or just the clutch.

My other problem is when I come to a stoplight and hold the clutch and brake in with the tranny in 1st. It will idle good for about 5-10 seconds, and then start loping really bad. About 25% of the time it will die.

Whats going on?

Try this link http://clubs.hemmings.com/clubsites/fieroswest/Tech%20Scene/Idle/Tech012002.htm It might give you some ideas, it's for the 2.8 engine.

[This message has been edited by avengador1 (edited 05-07-2004).]

How is the ECM wired? Does it think it's in drive?

Jon

I used ed parks manual harness. It idles fine while in neutral when I start it up. I will idle forever. It only does this when coming out of gear, or while holding the clutch in.

Do you have an ohm meter and know how to use it?

[This message has been edited by rockcrawl (edited 05-08-2004).]

no, but maybe I could learn?
Please tell me more.

I have the same problem. I have a 4.9 with a 4 speed and Ed Park’s wiring harness. If I am in 4th gear (have not tried it in 2nd or 3rd) and push the clutch in the RPMs drop off to zero. But if I let off the gas slowly and bring the engine down to an idle and push the clutch the engine will idle all day. I also need your help rockcrawl and I have an ohmmeter.

Disconnect the harness from the ECM. set the meter to ohms and put one meter lead on ground. use the other lead to probe the ECM connectors. Check pins A2, C10, F7, and F8. Let me know what you find.

I'm glad to hear I'm not alone.

I also have the same setup. 4.9, 3.65 4 speed, ed parks harness

I will try to get some readings. I think my dad has an ohm meter.

rockcrawl, I am new at this 4.9 stuff. Will I know where A2, C10, F7 and F8 are on the ECM when I look at it?

Thanks for your help.

ok, i have an ohm meter, and I'm gonna go get some readings right now.

my options on the meter are X1, X10, X1K, and another symbol that looks like a sound wave.

set the meter to X10 - connect the 2 meter ends together, you should get 0 (digital meter I assume), if not, make note at what it does read (or get a better meter).

Connect one lead to C10 and the other lead to ground (make sure you have a good connection) - should read 0 (or other noted reading), repeat for F7.

If not 0, check your ground connections - these 2 pins should be grounded. Thanks to Rockcrawl for this info.

ok, I adjusted it so it reads 0 when touching the leads.

F7 = 0 ohms

C10 = 0 ohms

A12 = 0 ohms?

there is no F8 or A2 in my harness

F7 = 0 ohms
C10 = 0 ohms
there is no F8 or A2 in my harness

That's what you want. Now we move onto the next item. Are any of you guys with this problem running one of my chips? If not, plug in a scantool and go for a ride. Look at vehicle speed on the scantool and compare it to the speedometer. Does the scantool value = ~1/6 of the speedometer value? If so, I can help you.

I am running your chip. My idle is 800 rpm.

Well I am trying to catch up here. I removed the consol and I am looking at the computer. There are 3 connectors on the driver’s side. I see no markings. How do I find A2, C10, F7 and F8? I am using the stock chip, computer is out of a 92 Deville.

look very closely! on the side with the pins there are numbers. on the side with the wires, there are letters. one connector is A/B, another is C/D, and the top one is E/F

I found the numbers, but the letters are just not there. If the top connector I E/F, I hope the center is C/d and the bottom one is A/B. Is the A, C, and E to the front of the and B, D, and E to the backside of the plug. If so F7 = 0 ohms and in connector A/B (the bottom connector) I did not have any wires in A2 or B2. Just to make sure I am looking at this correctly, all 3 connectors are facing the driver’s seat.

A, C, and E are on the top. E/F is top, C/D is middle, E/F is bottom.

bump

Well I am confused about the connectors and pins, I tinke I will move on and try and find someone in the area with a scantool and do that check.

J Gunsett, do you have his chip? I can't really do that test since my speedo isnt working. I am told my harness from ed was defective. and that I only need to cut 2 wires and it will work. I'm just not sure which ones. yellow and purple I think he said. hopefully rockcrawl will chime in and give me some advice. I'm headed to the massive junkyard to find some small radiator fans to put under my deck vents.

I am using a stock chip. I sent a request to rockcrawl to get a chip. My speedo should be correct as I did not change any thing on the 4 speed or the gauge cluster. I do know that the tach is off by about 450 rpm (I'll work on that). I noticed that mine seem to happen (the dieing problem) after the engine gets hot. I do get some good gas milage, 24 mpg and that was running at 80 mph for about 9 hours.

Jack

Possibly your speedo problem is that it lacks a ground. In my 84 the speedo was grounded through the factory PCM. When I removed the PCM, the ground was gone, and the speedo didn't work. Do you still have the factory PCM in there?

I've posted on the idle problem before. I'm a 3800 guy, but I think the same applies to you.

Seems like the problem occurs when engine braking. If you take your foot off the gas, the PCM closes the Idle Air Control solenoid to get it to hit the set idle point. The manual trans is 'pushing' the engine, then when you push the clutch in, the RPMs drop like a rock, and the IAC cannot open fast enough to keep it from dying.

I don't know if it's the same problem you're having, but I hope it helps a bit. For me it's not a big deal.

-Tim

We had that problem with our car (4.9 5spd) It was the oil pressure sender becuse it would idle down and the oil pressure would drop and it ecm thought that it was 0 and kill it. So we put a 88 oil pressure sender unit on it runs like a champ.

Joe Sokol III

interesting ideas. did you put a cadillac oil pressure sensor in? why 88? I'm assuming you used an 88' fiero oil pressure sensor?

There is no low oil pressure cutout. The oil pressure switch can't shut off the engine unless it's wired wrong or the fuel pump relay or ECM is bad.

what do you think is causing this rockcrawl?