Stumbling and Studdering

[fast65]

Alright, I'll see what I can find. Thanks!

[GAboySVO]

You mean the other two are VAM and VAT. The SVO doesn't have a MAF or IAT unless its been converted.

[BrianO]

exactly

[fast65]

A test of the VAM showed 255mV at rest, so I need a new VAM?

[fast65]

I was also wondering, how would I know if it was the actual computer causing problems, rather than other things?

[BrianO]

heres teh thread on testing it.. with diagram courtesy of navy

http://www.svoca.com/forum/showthread.php?t=23681

[fast65]

Thanks Brian, I tested and it came back with 255mV, so do I need a new VAM?

[fast65]

Well I replaced the VAM and the problem still persists. What else could it be?

The fuel pressure isn't dumping when the problem happens either, it's remaining constant.

[GAboySVO]

Well I replaced the VAM and the problem still persists. What else could it be?

The fuel pressure isn't dumping when the problem happens either, it's remaining constant.

Wires to the VAM or VAT.

[SeaFoam]

Thanks Brian, I tested and it came back with 255mV, so do I need a new VAM?

I just tested mine the other day - there was another thread on here about testing the VAM. You probably can't take that new one back, but if you can the resting is 255 and full open is around 4.5!

[pstocker]

Just a quick question for you. How long does it run before it starts to lose power, and, when it does and you come to a stop, does the engine quit?

[fast65]

Just a quick question for you. How long does it run before it starts to lose power, and, when it does and you come to a stop, does the engine quit?

Quite honestly I can't remember exactly. Initially it took about 10 minutes before it started, but then that time period shortened. I don't believe it does die when I come to a stop, but I'm not 100% sure.

[pstocker]

Possible fuel pump or maybe fuel filter? Have you tried replacing the filter?

[Alex L]

You mean the other two are VAM and VAT. The SVO doesn't have a MAF or IAT unless its been converted.

54 = failure of ACT/IAT. VAT throws a 58 on LA3. 54 is an expected code unless you've added an ACT sensor with the LA3 swap. so that leaves ..

the 66, which is MAF/VAM went below .4v during operation, there are a few things that can cause this. since you already eliminated the VAM as a possible issue, the problem likely lies in the harness. did you check the VREF as well as the VAF pins as documented in the troubleshooting guide that navy posted in the other thread? VAF should be 1-5v full sweep. if you're getting .255v at the VAF pin at the VAM, vane closed, with both new and old VAMs, something else is wrong. either VREF is low at the VAM, or VAF is shorting to ground.

either of which likely points to something busted up in the harness. if i were in your shoes, id just start unwrapping the harness starting at the VAM connector and surveying the damages. 84s are not known for their quality harness insulation; most likely that chunk of harness is turning to dust.

[fast65]

54 = failure of ACT/IAT. VAT throws a 58 on LA3. 54 is an expected code unless you've added an ACT sensor with the LA3 swap. so that leaves ..

the 66, which is MAF/VAM went below .4v during operation, there are a few things that can cause this. since you already eliminated the VAM as a possible issue, the problem likely lies in the harness. did you check the VREF as well as the VAF pins as documented in the troubleshooting guide that navy posted in the other thread? VAF should be 1-5v full sweep. if you're getting .255v at the VAF pin at the VAM, vane closed, with both new and old VAMs, something else is wrong. either VREF is low at the VAM, or VAF is shorting to ground.

either of which likely points to something busted up in the harness. if i were in your shoes, id just start unwrapping the harness starting at the VAM connector and surveying the damages. 84s are not known for their quality harness insulation; most likely that chunk of harness is turning to dust.

Alright, thanks, I'll call my brother and see if he can check that...seeings as I'm 4 hours away from the car :/