Thread: Td5 V8

Originally Posted by TheEntertainer

Don’t [emoji23], upgraded the maf on my td5 and it seems it’s upgraded the engine to a V8.. well at least fuel consumption wise. Getting loads of power… but the EGT on the madman ems3 peaks at 720 with only the smallest inclines. I’ll take a recording on the nanocom tomorrow. Has any one experienced this new maf with extreamly high fuel consumption @ 6kl per L.
Thanks all

No, but if the MAF over reads it will then overfuel on acceleration, as you said the log will help decipher.

What MAF did you fit?

Anything except genuine or VDO are terrible in my experience.

I cannot see how a MAF can do that.
I would be looking at your wastegate thread unwinding and giving low boost=high EGTs.
As I was driving back from Wodonga with my new van , I suddenly saw the EGT gauge looking high and the boost low, and that is what happened. Took me several minutes to diagnose then all well again.
Another reason could be the handbrake dragging or caliper frozen.
Regards PhilipA

Originally Posted by PhilipA

I cannot see how a MAF can do that.

Absolutely it can, if the MAF is not reading correctly, the AFR will be totally messed up.

Probably 90% of failed MAF's I see under read, but I think I have had one over read.

You will get better performance with an over reader, but also smoke and high EGT.


This only applies to EU3 though.

Absolutely it can, if the MAF is not reading correctly, the AFR will be totally messed up.

I had an over reader and it did not do that.
What it did was revert to zero at high load high revs and caused a big miss and dropout.
Regards PhilipA

Originally Posted by PhilipA

I had an over reader and it did not do that.
What it did was revert to zero at high load high revs and caused a big miss and dropout.
Regards PhilipA

A MAF can fail, but the results can be vastly different to another failed MAF.

For instance, in your case I'd take a punt that it had exceeded the stock 710kg/hr reading, then it would read zero, The ECU would fall back to speed density method, you'd get a power glitch and be on your way again.

The other way would be that it could be over or under reading outside of the error checking routine limits in the mapping - not to be confused with the kg/hr limit.

So for instance it could be reading over about 1600mg/stroke at a certain rev range, the ECU will again drop back to speed density, you will get a power glitch and be on your way.

I've had cheap(and some not so cheap) MAFS here that will under read at idle when air temp is low, but then be ok through the mid rev range or when the air temp rises.

This will give you a very very laggy experience off the line, but may be ok when cruising.

The one the OP has may be over reading through mid range flow levels, but then flattening off up high, which will avoid the fuelling method OOR changeover glitch, but still provide smoke and high EGT down lower.

That's why running anything except a genuine or VDO MAF is fraught with issues.

I know fery will say "Genuine only" and I won't argue with him on that, he has probably looked into it much more than I, but I have found the VDO to be at the very least quite serviceable.

It would be interesting to have a new genuine, and VDO and test side by side, but it would take a lot of time and logging.



Cheers
James

I'll have a bit more time shortly and I'll post up a comparison of some different MAF's I have laying around, and also the fuelling consequences of each.

Hi all,
Just back from the property, don't have mobile reception there. Below is heading up a hill with a trailer. I did forget to mention that I've removed the silencer box and replace the mid section with a straight though. The MAF I bought from TR spares and is a VDO sensor. By the time I got to line 2571 or a road speed of 97 down from 103 the EGT was reading 700, I have the ems 3 set at 700 so I started to back of on fuel to keep the temp under 700.
snippit below

Engine speed (rpm)

Road speed

Coolant temp. (C)

Turbo pres. (kPa)

Battery volt. (V)

Ambient pres. (kPa)

Air flow (g/s)

Air inlet temp. (C)

Fuel temp. (C)

Cyl. 1

Cyl. 2

Cyl. 3

Cyl. 4

Cyl. 5

Accel. track 1 (V)

Accel. track 2 (V)

Accel. track 3 (V)

Accel. supply (V)

EGR inlet (%)

EGR mod. (%)

Idle speed error

Wastegate mod.(%)

2480	103	89.5	159.8	13.78	93.8	303.2	27.6	71.8	-2	0	7	-5	0	2.834	2.285	2.579	5.015	38.68	0	1525	38.5
2442	102	90	155.8	13.91	93.8	289.8	27.8	68.5	-2	2	3	-2	4	2.773	2.341	2.658	5.01	39.31	0	1490	39.2
2407	100	90	154.9	13.97	94.47	289.8	27.8	68.5	-5	1	3	-8	5	2.773	2.346	2.658	5.01	39.93	0	1445	39.9
2356	97	90	154.9	13.94	94.06	283.8	28.1	68.5	0	1	-1	-4	-2	2.773	2.341	2.663	5.01	40	0	1414	40
2329	97	90.3	156	13.88	93.8	279.2	28.2	68.6	2	1	1	-3	2	2.796	2.319	2.628	5.01	40	0	1368	40
2288	95	90.3	155.8	13.91	93.8	284.7	28.5	68.5	0	4	1	-3	-3	2.806	2.306	2.614	5.01	40	0	1333	40
2253	94	90.3	152	13.94	94.06	272.2	28.5	68.5	-4	2	3	-1	-1	2.757	2.352	2.678	5.01	40	0	1305	40
2224	92	90.3	153.3	13.91	93.94	264.2	28.6	68.5	-1	4	5	-3	-5	2.78	2.335	2.648	5.01	40	0	1272	40
2201	91	90.6	153.7	13.94	94.33	269.8	28.7	68.5	2	2	3	-2	-3	2.78	2.335	2.653	5.01	40	0	1257	40
2173	90	90.6	153.1	13.94	93.94	258.5	28.7	68.5	1	-4	5	-2	-3	2.773	2.341	2.653	5.01	40	0	1227	40
2145	90	91	152.6	13.94	93.8	252.6	28.8	68.5	-1	-1	6	-2	-2	2.773	2.341	2.658	5.01	40	0	1201	40
2133	89	91	153.4	13.94	93.8	252.6	29	68.5	-2	0	4	2	-4	2.773	2.341	2.658	5.01	40	0	1182	40
2107	88	91	152.8	13.72	94.06	253.5	29.1	68.5	0	0	2	-2	-3	2.773	2.341	2.658	5.01	40	0	1168	40
2088	86	91	152.6	13.97	93.94	249.8	29.1	68.5	-1	0	5	-2	2	2.773	2.341	2.658	5.015	40	0	1151	40
2083	86	91.5	152.8	13.91	93.94	251.3	29.2	68.5	1	-1	2	-3	1	2.773	2.341	2.658	5.01	40	0	1136	40
2064	85	91.5	152.6	13.94	93.8	246.3	29.2	68.5	-1	-1	1	0	0	2.78	2.335	2.653	5.01	40	0	1130	40
2056	85	91.5	153.7	13.91	94.06	249.6	29.2	68.5	-1	-1	4	1	-3	2.871	2.25	2.53	5.01	40	0	1111	40
2045	84	91.9	158.4	13.94	94.06	253.5	29.3	68.5	-2	-1	6	-4	-1	2.871	2.25	2.53	5.01	40	0	1108	40
2047	84	91.9	158.1	13.78	93.54	250.1	29.5	68.5	-3	3	5	1	-2	2.865	2.25	2.53	5.01	40	0	1104	40
2041	84	91.9	157.8	13.94	93.94	249.3	29.5	68.5	2	6	3	-3	-2	2.871	2.244	2.526	5.01	40	0	1101	40
2045	85	91.9	157.5	13.85	93.8	255	29.7	68.5	1	-1	1	0	-5	2.865	2.25	2.536	5.01	40	0	1107	40
2041	84	91.5	145.4	13.75	94.06	220.5	29.7	68.3	-4	3	0	-1	-1	2.246	2.852	3.367	5.015	40	0	1093	39.84
2028	84	91.9	139.5	13.56	93.8	224.3	29.7	68.4	1	0	3	-3	-3	2.769	2.346	2.668	5.01	40	0	1094	40
2028	84	91.9	153.5	13.94	93.94	247.1	29.7	68.5	-2	2	6	-2	-4	2.849	2.267	2.561	5.01	40	0	1090	40
2036	84	92.1	155.7	13.91	93.94	249.3	29.7	68.5	-1	-1	2	0	-2	2.849	2.267	2.54	5.015	40	0	1092	40
2040	84	92.1	153.7	13.94	93.68	246.3	29.7	68.5	0	0	2	0	-4	2.806	2.306	2.614	5.01	40	0	1101	40
2050	84	92.1	152	13.94	93.68	243.8	29.8	68.5	0	1	2	0	-2	2.742	2.375	2.701	5.01	40	0	1107	40
2052	85	92.1	149.9	13.91	93.68	242.3	29.8	68.3	0	0	1	0	-3	2.742	2.369	2.701	5.01	40	0	1115	40
2068	85	92.5	149.9	13.91	94.06	242	30.1	68.3	2	1	5	-3	-5	2.742	2.369	2.701	5.015	40	0	1129	40
2069	86	92.5	144.7	13.88	93.8	232.6	29.8	68.3	0	0	3	-1	-1	2.661	2.454	2.815	5.01	40	0	1139	40
2079	86	92.5	147	13.94	94.06	242.8	29.8	68.6	2	2	-1	1	-1	2.72	2.391	2.732	5.01	40	0	1140	40
2085	86	92.3	140.3	13.5	93.94	222.6	30.1	68.3	-1	-1	2	-1	0	2.354	2.75	3.224	5.01	40	0	1147	40
2094	88	92.5	132.8	13.94	94.19	215.8	30.1	68.3	1	-1	0	1	-2	2.461	2.648	3.084	5.01	40	0	1155	40
2102	86	93	137.1	13.94	94.06	229.3	30	68.3	-1	0	4	1	-3	2.569	2.539	2.937	5.01	40	0	1171	40